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## PART I.

# PHYSIOLOGY.

## CHAPTER I.

# BIOLOGY.

In this chapter we propose to consider Life in its primitive manifestations. Biology is the science of living bodies, or the science of life. Every organ of a living body has a function to perform, and Physiology treats of these functions.

Function means the peculiar action of some particular organ or part. There can be no vital action without change, and no change without organs. Every living thing has a structure, and Anatomy treats of the structures of organized bodies. Several chapters of this work are devoted to Physiological Anatomy, which treats of the human organism and its functions.

The beginning of life is called generation; its perpetuation, reproduction. By the former function, individual life is insured; by the latter, it is maintained. Since nutrition sustains life, it has been pertinently termed perpetual reproduction.

Latent Life is contained in a small globule, a mere atom of matter, in the sperm-cell. This element is something which, under certain conditions, develops into a living organism. The entire realm of nature teems with these interesting phenomena, thus manifesting that admirable adjustment of internal to external relations, which claims our profound attention. We [pg 12]are simply humble scholars, waiting on the threshold of nature's glorious sanctuary, to receive the interpretation of her divine mysteries.

Some have conjectured that chemical and physical forces account for all the phenomena of life, and that organization is not the result of vital forces. Physical science cannot inform us what the beginning was, or how vitality is the result of chemical forces; nor can it tell us what transmutations will occur at the end of organized existence. This mysterious life-principle eludes the grasp of the profoundest scientists, and its presence in the world will ever continue to be an astonishing and indubitable testimony of Divine Power.

The physical act of generation is accomplished by the union of two cells; and as this conjugation is known to be so generally indispensable to the organization of life, we may fairly infer that it is a universal necessity. Investigations with the microscope have destroyed the hypothesis of "spontaneous generation." These show us that even the minutest living forms are derived from a parent organization.

Generation. So long as the vital principle remains in the sperm-cell, it lies dormant. That part of the cell which contains this principle is called the spermatozoön, which consists of a flattened body, having a long appendage tapering to the finest point. If it be remembered that a line is the one-twelfth part of an inch in length, some idea may be formed of the extreme minuteness of the body of a human spermatozoön, when we state that it is from 1/800 to 1/600 part of a line, and the filiform tail 1/50 of a line, in length. This life-atom, which can be discerned only with a powerful magnifying glass, is perfectly transparent, and moves about by executing a vibratile motion with its long appendage. Within this speck of matter are hidden the multifarious forces which, under certain favorable conditions, result in organization. Magnify this infinitesimal atom a thousand times, and no congeries of formative powers is perceived wherewith to work out the wonders of its existence. Yet it contains the principle, which is the contribution on the part of the male toward the generation of a new being.

The ovum or germ-cell, is the special contribution on the [pg 13]part of the female for the production of another being. The human ovum, though larger than the spermatozoön, is also extremely small, measuring not more than from 1/20 to 1/10 of a line, or from 1/240 to 1/120 of an inch, in diameter.

Fig. 1. A. Human Spermatozoön magnified about 3,800 diameters. B. Vertical and lateral views of spermatozoa of man. C, D, E, F. Development of spermatozoa within the vesicles of evolution. G. Cell of the sponge resembling a spermatozoön. H. Vesicles of evolution from the seminal fluid of the dog in the parent cell I. Single vesicles of different sizes. J. Human spermatozoön forming in its cell. K. Rupture of the cell and escape of the spermatozoön.

The sperm and the germ-cells contain the primary elements of all organic structures, and both possess the special qualities and conditions by which they may evolve organic beings. Every cell is composed of minute grains, within which vital action takes [pg 14]place. The interior of a cell consists of growing matter; the exterior, of matter which has assumed its form and is less active.

When the vital principle is communicated to it, the cell undergoes a rapid transformation. While this alteration takes place within the cell, deteriorating changes occur in the cell-wall. Although vital operations build up these structures, yet the animal and nervous functions are continually disintegrating, or wasting, them.

Throughout the animal kingdom, germ-cells present the same external aspect when carefully examined with the microscope. No difference can be observed between the cells of the flowers of the oak and those of the apple, but the cells of the one always produce oak trees, while those of the other always produce apple trees. The same is true of the germs of animals, there being not the slightest apparent difference. We are unable to perceive how one cell should give origin to a dog, while another exactly like it becomes a man. For aught we know, the ultimate atoms of these cells are identical in physical character; at least we have no means of detecting any difference.

Species. The term species is generally used merely as a convenient name to designate certain assemblages of individuals having various striking points of resemblance. Scientific writers, as a rule, no longer hold that what are usually called species are constantly unvarying and unchangeable quantities. Recent researches point to the conclusion that all species vary more or less, and, in some instances, that the variation is so great that the limits of general specific distinctness are sometimes exceeded.

Our space will not permit us to do more than merely indicate the two great fundamental ideas upon which the leading theories of the time respecting the origin of species are based. These are usually termed the doctrine of Special Creation and the doctrine of Evolution. According to the doctrine of Special Creation, it is thought that species are practically immutable productions, each species having a specific centre where it was originally created, and from which it spread over a certain area until its further progress was obstructed by unfavorable conditions. The advocates of the doctrine of Evolution hold, on the contrary, that species are not permanent and immutable, but that they are subject to modification, and that "the existing forms of life are [pg 15]descendants by true generation of pre-existing forms."[1] Most naturalists are now inclined to admit the general truth of the theory of evolution, but they differ widely respecting the mode in which it occurred.

### THE PROCESS OF GENERATION.

The vital principle, represented in the sperm-cell by a spermatozoön, must be imparted to a germ-cell in order to effect impregnation. After touching each other, separate them immediately, and observe the result. If, with the aid of a powerful lens, we directly examine the spermatozoön, it will be perceived that, for a short time, it preserves its dimensions and retains all its material aspects. But it does not long withstand the siege of decay, and, having fulfilled its destiny, loses its organic characteristics, and begins to shrink.

If we examine the fertilized germ, we discover unusual activity, the result of impregnation. Organic processes succeed one another with wonderful regularity, as if wrought out by inexplicable intelligence. Here begin the functions which constitute human physiology.

Generation requires that a spermatozoön be brought into actual contact with a germ that fecundation may follow. If a spermatic cell, or spermatozoön, together with several unimpregnated ova, no matter how near to one another, if not actually touching, be placed on the concave surface of a watch-crystal, and covered with another crystal, keeping them warm, and even though the vapor of the ova envelops it, no impregnation will occur. Place the spermatozoön in contact with an ovum, and impregnation is instantly and perfectly accomplished. Should this vitalizing power be termed nerve-force, electricity, heat, or motion? It is known that these forces may be metamorphosed; for instance, nervous force may be converted into electricity, electricity into heat, and heat into motion, thus illustrating their affiliation and capability of transformation. But nothing is explained respecting the real nature of the vital principle, if we assert its identity with any of these forces; for who can reveal the true nature of any of these, or even of matter?

[pg 16]

### ALTERNATE GENERATION.

In several insect families, the species is not wholly represented in the adult individuals of both sexes, or in their development, but, to complete this series, supplementary individuals, as it were, of one or of several preceding generations, are required. The son may not resemble the father, but the grandfather, and in some instances, the likeness re-appears only in latter generations. Agassiz states: "Alternate generation was first observed among the Salpæ. These are marine mollusks, without shells, belonging to the family Tunicata. They are distinguished by the curious peculiarity of being united together in considerable numbers so as to form long chains, which float in the sea, the mouth(m) however being free in each.

Fig. 2.

Fig. 3.

"Fig. 2. The individuals thus joined in floating colonies produce eggs; but in each animal there is generally but one egg formed, which is developed in the body of the parent, and from which is hatched a little mollusk.

"Fig. 3, which remains solitary, and differs in many respects from the parent. This little animal, on the other hand, does not produce eggs, but propagates, by a kind of budding, which gives rise to chains already seen in the body of their parent(a), and these again bring forth solitary individuals, etc."

It therefore follows that generation in some animals require? two different bodies with intermediate ones, by means of which and their different modes of reproduction, a return to the original stock is effected.

Universality of Animalcular Life.—Living organisms are universally diffused over every part of the globe. The gentle zephyr wafts from flower to flower invisible, fructifying atoms, which quicken beauty and fragrance, giving the promise of a golden fruitage, to gladden and nourish a dependent world. Nature's own sweet cunning invests all living things [pg 17]constraining into her service chemical affinities, arranging the elements and disposing them for her own benefit, in such numberless ways that we involuntarily exclaim,

> "The course of Nature is the art of God."

The microscope reveals the fact that matter measuring only 1/120000 of an inch diameter may be endowed with vitality, and that countless numbers of animalcules often inhabit a single drop of stagnant water. These monads do not vary in form, whether in motion or at rest. The life of one, even, is an inexplicable mystery to the philosopher. Ehrenberg writes: "Not only in the polar regions is there an uninterrupted development of active microscopic life, where larger animals cannot exist, but we find that those minute beings collected in the Antarctic expedition of Captain James Ross exhibit a remarkable abundance of unknown, and often most beautiful forms."

Even the interior of animal bodies is inhabited by animalcules. They have been found in the blood of the frog and the salmon, and in the optic fluid of fishes. Organic beings are found in the interior of the earth, into which the industry of the miner has made extensive excavations, sunk deep shafts, and thus revealed their forms; likewise, the smallest fossil organisms form subterranean strata many fathoms deep. Not only do lakes and inland seas abound with life, but also, from unknown depths, in volcanic districts, arise thermal springs which contain living insects. Were we endowed with a microscopic eye, we might see myriads of ethereal voyagers wafted by on every breeze, as we now behold drifting clouds of aqueous vapor. While the continents of earth furnishes evidences of the universality of organic beings, recent observations prove that "animal life predominates amid the eternal night of the depths of the liquid ocean."

### THE ORIGIN OF LIFE.

The ancients, rude in many of their ideas, referred the origin of life to divine determination. The thought was crudely expressed, but well represented, in the following verse:

> "Then God smites his hands together,
> And strikes out a soul as a spark,
> Into the organized glory of things.
> From the deeps of the dark."

[pg 18]According to a Greek myth, Prometheus formed a human image from the dust of the ground, and then, by fire stolen from heaven, animated it with a living soul. Spontaneous generation once held its sway, and now the idea of natural evolution is popular. Some believe that the inpenetrable mystery of life is evolved from the endowments of nature, and build their imperfect theory on observations of her concrete forms and their manifestations, to which all our investigations are restricted. But every function indicates purpose, every organism evinces intelligent design, and all proclaim a Divine Power. Something cannot come out of nothing. With reason and philosophy, chance is an impossibility. We, therefore, accept the display of wisdom in nature as indicative of the designs of God. Thus "has He written His claims for our profoundest admiration and homage all over every object that He has made." If you ask: Is there any advantage in considering the phenomena of nature as the result of DIVINE VOLITION? we answer, that this belief corresponds with the universally acknowledged ideas of accountability; for, with a wise, and efficient Cause, we infer there is an intelligent creation, and the desire to communicate, guide and bless, is responded to by man, who loves, obeys, and enjoys. Nothing is gained by attributing to nature vicegerent forces. Is it not preferable to say that she responds to intelligent, loving Omnipotence? Our finiteness is illustrated by our initiation into organized being. Emerging from a rayless atom, too diminutive for the sight, we gradually develop and advance to the maturity of those conscious powers, the exercise of which furnishes indubitable evidence of our immortality. We are pervaded with invisible influences, which, like the needle of the compass trembling on its pivot, point us to immortality as our ultimate goal, where in the sunny clime of Love, even in a spiritual realm of joy and happiness, we may eternally reign with Him who is all in all.

[pg 19]

## CHAPTER II.

# PHYSIOLOGICAL ANATOMY.

### THE BONES.

All living bodies are made up of tissues. There is no part, no organ, however soft and yielding, or hard and resisting, which has not this peculiarity of structure. The bones of animals, as well as their flesh and fat, are composed of tissues, and all alike made up of cells. When viewed under a microscope, each cell is seen to consist of three distinct parts, a nucleolus, or dark spot, in the center of the cell, around which lies a mass of granules, called the nucleus; and this, in turn, is surrounded with a delicate, transparent membrane, termed the envelope. Each of the granules composing the nucleus assimilates nourishment, thereby growing into an independent cell, which possesses a triple organization similar to that of its parent, and in like manner reproduces other cells.

Fig. 4. Nucleated cell. From Goeber. 1. Periphery of the cell, or cell-wall. 2. Nucleus. 3. Nucleolus in the center.

A variety of tissues enters into the composition of an animal structure, yet their differences are not always distinctly marked, since the characteristics of some are not unlike those of others. We shall notice, however, only the more important of the tissues.

The Areolar, or Connective Tissue, is a complete network of delicate fibers, spread over the body, and serves to bind the various organs and parts together. The fibrous and serous tissues are modifications of the areolar.

[pg 20]The Nervous Tissue is of two kinds: The gray, which is pulpy and granulated, and the white fibrous tissue. The Adipose Tissue is an extremely thin membrane, composed of closed cells which contain fat. It is found principally just beneath the skin, giving it a smooth, plump appearance.

Fig. 5. Arrangement of fibers in the Areolar Tissue. Magnified 135 diameters.

The Cartilaginous Tissue consists of nucleated cells, and, with the exception of bone, is the hardest part of the animal frame. The Osseous Tissue, or bone, is more compact and solid than the cartilaginous, for it contains a greater quantity of lime. The Muscular Tissue is composed of bundles of fibers, which are enclosed in a cellular membrane.

Fig. 6. Human Adipose Tissue.

Various opinions have been entertained in regard to the formation, or growth, of bone. Some anatomists have supposed that all bone is formed in cartilage. But this is not true, for there is an intra-membranous, as well as an intra-cartilaginous, formation of bone, as may be seen in the development of the cranial bones, where the gradual calcification takes place upon the inner layers of the fibrous coverings. Intra-cartilaginous deposit is found in the vicinity of the blood-vessels, within the cartilaginous canals; also, there are certain points first observed in the shafts of long bones, called centers of ossification. These points are no sooner formed than the cartilage corpuscles arrange themselves in concentric zones, and, lying in contact with one another, become very compact. As ossification proceeds, the cup-shaped cavities are converted into closed interstices of bone, with extremely thin lamellæ, or layers. These, however, soon increase [pg 21]in density, and no blood-vessels can be observed within them.

Fig. 7. Vertical section of cartilage near the surface of ossification. 1. Ordinary appearance of the temporary cartilage. 1'. Portion of the same more highly magnified. 2. The cells beginning to form into concentric zones. 2'. Portion more magnified. 3. The ossification is extending in the inter-cellular spaces, and the rows of cells are seen resting in the cavities so formed, the nuclei being more separated than above. 3'. Portion of the same more highly magnified.

Fig. 8. Thigh-bone, sawn open lengthwise.

Fig. 9. Lower end of the thigh-bone sawn across, showing its central cavity.

The bony plates form the boundaries of the Haversian, or nutritive canals of the bones. In the second stage of ossification, the cartilage corpuscles are converted into bone. Becoming flattened against the osseous lamellæ already formed, they crowd upon one another so as to entirely obliterate the lines that distinguish them; and, simultaneously with these changes, a calcareous deposit takes place upon their interior. Bones grow by additions to their ends and surfaces. In the child, their extremities are [pg 22]separated from the body of the bone by layer of cartilage, and the cancellated, or cellular structure, which remains for a time in the interior, represents the early condition of the ossifying substances.

The bones contain more earthy matter in their composition than any other part of the human body, being firm, hard, and of a lime color. They compose the skeleton or frame work, and, when united by natural ligaments, form what is known as the natural skeleton; when they are wired together, they are called an artificial skeleton. The number of bones in the human body is variously estimated; for those regarded as single by some anatomists are considered by others to consist of several distinct pieces. There are two hundred distinct bones in the human skeleton besides the teeth. These may be divided into those of the Head, Trunk, Upper Extremities, and Lower Extremities.

Fig. 10. The bones of the skull separated. 1. Frontal, only half is seen. 2. Parietal. 3. Occipital, only half is seen. 4. Temporal. 5. Nasal. 6. Malar. 7. Superior maxillary (upper jaw). 8. Lachrymal. 9. Inferior maxillary (lower jaw). Between 4 and 6 a part of the sphenoid or wedge-shaped bone, is seen. Another bone assisting to form the skull, but not here seen, is called the ethmoid (sieve-like, from being full of holes), and is situated between the sockets of the eyes, forming the roof of the nose.

The Bones of the Head are classed as follows: eight belonging to the Cranium, and fourteen to the Face. The bones of the Cranium are the occipital, two parietal, two temporal, frontal, sphenoid, and ethmoid. Those composing the face are, the two nasal, two superior maxillary, two lachrymal, two malar two palate, two inferior turbinated, vomer, and inferior maxillary. The cranial bones are composed of two dense plates, between which there is, in most places a cancellated or cellular tissue. The external [pg 23]plate is fibrous, the internal, compact and vitreous. The skull is nearly oval in form, convex externally, the bone being much thicker at the base than elsewhere, and it is, in every respect admirably adapted to resist any injury to which it may be exposed, thus affording ample protection to the brain substance which it envelops. The internal surface of the cranium presents eminences and depressions for lodging the convolutions of the brain, and numerous furrows for the ramifications of the blood-vessels. The bones of the cranium are united to one another by ragged edges called sutures, which are quite distinct in the child but which in old age are nearly effaced. Some authorities suppose that by this arrangement the cranium is less liable to be fractured by blows; others think that the sutures allow the growth of these bones, which takes place by a gradual osseous enlargement at the margins. The bones of the Face are joined at the lower part and in front of the cranium, and serve for the attachment of powerful muscles which assist in the process of mastication. Although the soft parts of the face cover the bony structure, yet they do not conceal its principal features, or materially change its proportions. The form of the head and face presents some remarkable dissimilarities in different races.

Fig. 11. 1. The first bone of the sternum (breast-bone). 2. The second bone of the sternum. 3. The cartilage of the sternum. 4. The first dorsal vertebra (a bone of the spinal column). 5. The last dorsal vertebra. 6. The first rib. 7. Its head. 8. Its neck. 9. Its tubercle. 10. The seventh or last true rib. 11. The cartilage of the third rib. 12. The floating ribs.

Fig. 12. A vertebra of the neck. 1. The body of the vertebra. 2. The spinal canal. 4. The spinous process cleft at its extremity. 5. The transverse process. 7. The interior articular process. 8. The superior articular process.

The Trunk has fifty-four bones, which are as follows: The Os Hyoides, the Sternum, twenty-four Ribs, twenty-four vertebræ or bones of the Spinal Column, the Sacrum, the Coccyx, and two Ossa Innominata. The Os Hyoides, situated at the base of the tongue, is the most isolated bone of the skeleton, and serves for the attachment of [pg 24]muscles. The Sternum, or breast-bone, in a child is composed of six pieces, in the adult of three, which in old age are consolidated into one bone. The Ribs are thin, curved bones, being convex externally. There are twelve on each side, and all are attached to the spinal column. The seven upper ribs, which are united in front of the sternum, are termed true ribs; the next three, which are not attached to the sternum, but to one another are called false ribs; and the last two, which are joined only to the vertebræ, are designated as floating ribs. The first rib is the shortest, and they increase in length as far as the eighth, after which this order is reversed.

Fig. 13. 1. The cartilaginous substance which connects the bodies of the vertebræ. 2. The body of the vertebra. 3. The spinous process. 4,4. The transverse processes. 5,5. The articular processes. 6,6. A portion of the bony bridge which assists in forming the spinal canal (7).

Fig. 14. Backbone, spinal column, or vertebral column. All animals possessing such a row of bones are called vertebrates. Above b are the cervical (neck) vertebræ; b to c, dorsal (back) or chest vertebræ; c to d, lumbar (loins) vertebræ; d to e, sacrum; e to f, coccyx.

The Spinal Column or backbone, when viewed from the front presents a perpendicular appearance, but a side view shows four distinct curves. The bones composing it are called vertebræ. The body part of a vertebra is light and spongy in texture, having seven projections called processes, four of which are the articular processes, which furnish surfaces to join the different vertebræ of the spinal column. Two are called transverse, and the remaining one is termed the spinous. The transverse [pg 25]and spinous processes serve for the attachment of the muscles belonging to the back. All these processes are more compact than the body of the vertebra, and, when naturally connected, are so arranged as to form a tube which contains the medulla spinalis, or spinal cord. Between the vertebræ is a highly-elastic, cartilaginous and cushion-like substance, which freely admits of motion, and allows the spine to bend as occasion requires. The natural curvatures of the spinal column diminish the shock produced by falling, running or leaping, which would otherwise be more directly transmitted to the brain. The ribs at the sides, the sternum in front, and the twelve dorsal bones of the spinal column behind, bound the thoracic cavity, which contains the lungs, heart, and large blood-vessels.

Fig. 15. A representation of the pelvic bones. e. The lumbo-sacral joint. 2. The sacrum. 3. Coccyx. 1, 1. The innominata. 4,4. Acetabula.

The Pelvis is an open bony structure, consisting of the Os Innominata, one on either side, and the Sacrum and Coccyx behind. The Sacrum, during childhood, consists of five bones, which in later years unite to form one bone. It is light and spongy in texture, and the upper surface articulates with the lowest vertebra, while it is united at its inferior margin to the coccyx. The Coccyx is the terminal bone of the spinal column. In infancy it is cartilaginous and composed of several pieces, but in the adult these unite and form one bone. The Innominata, or nameless bones, during youth, consist of three separate pieces on each side; but as age advances they coalesce and form one bone. A deep socket, called the acetabulum, is found near their junction, which serves for the reception of the head of the thigh-bone.

Fig. 16. 1. Portions of the backbone. 2. Cranial bones. 4. Breast-bone. 5. Ribs. 7. Collar-bone. 8. Arm-bone (humerus). 9. Shoulder-joint. 10, 11. Bones of the fore-arm (ulna and radius). 12. Elbow-joint. 13. Wrist-joint. 14. Bones of the hand. 15, 16. Pelvic bones. 17. Hip-joint. 18. Femur. 19, 20. Bones of the knee-joint. 21, 22. Fibula and tibia. 23. Ankle bone. 24. Bones of the foot.

The Bones of the Upper Extremities are sixty-four in number, and are classified as follows: The Scapula, [pg 26]Clavicle, Humerus, Ulna, Radius, Carpus, Metacarpus, and Phalanges. The Scapula, or shoulder-blade, is an irregular, thin, triangular bone, situated at the posterior part of the shoulder, and attached to the upper and back part of the chest. The Clavicle, or collar-bone, is located at the upper part of the chest, between the sternum and scapula, and connects with both. Its form resembles that of the italic letter f, and it prevents the arms from sliding forward. The Humerus, the first bone of the arm, is long, cylindrical, and situated between the scapula and fore-arm. The Ulna is nearly parallel with the radius, and situated on the inner side of the fore-arm. It is the longer and larger of the two bones, and in its articulation with the humerus, forms a perfect hinge-joint. The Radius, so called from its resemblance to a spoke, is on the outer side of the fore-arm, and articulates with the bones of the wrist, forming a joint. The ulna and radius also articulate with each other at their extremities. The Carpus, or wrist, consists of eight bones, arranged in two rows. The Metacarpus, or palm of the hand, is composed of five bones [pg 27]situated between the carpus and fingers. The Phalanges, fourteen in number, are the bones of the fingers and thumb, the fingers each having three and the thumb two.

The Bones of the Lower Extremities, sixty in number, are classed as follows: The Femur, Patella, Tibia, Fibula, Tarsus, Metatarsus, and Phalanges. The Femur, or thigh-bone, is the longest bone in the body. It has a large round head, which is received into the acetabulum, thus affording a good illustration of a ball and socket joint. The Patella, or knee-pan, is the most complicated articulation of the body. It is of a round form, connects with the tibia by means of a strong ligament, and serves to protect the front of the joint, and to increase the leverage of the muscles attached to it, by causing them to act at a greater angle. The Tibia, or shin bone, is enlarged at each extremity and articulates with the femur above and the astragalus, the upper bone of the tarsus, below. The Fibula, the small bone of the leg, is situated on the outer side of the tibia, and is firmly bound to it at each extremity. The Tarsus, or instep, is composed of seven bones, and corresponds to the carpus of the upper extremities. The Metatarsus, the middle of the foot, bears a dose resemblance to the metacarpus, and consists of five bones situated between the tarsus and the phalanges. The tarsal and the metatarsal bones are so united as to give an arched appearance to the foot, thus imparting elasticity. The Phalanges, the toes, consist of fourteen bones, arranged in a manner similar to that of the fingers.

We are not less interested in tracing the formation of bone through its several stages, than in considering other parts of the human system. The formation of the Haversian canals for the passage of blood-vessels to nourish the bones, the earlier construction of bony tissue by a metamorphosis of cartilaginous substance, and also the commencement of ossification at distinct points, called centers of ossification, are all important subjects, requiring the student's careful attention. The bones are protected by an external membranous envelope, which, from its situation is called the periosteum. The bones are divided into four classes, long, short, flat and irregular, being thus adapted to subserve a variety of purposes.

The Long Bones are found in the limbs, where they act as [pg 28]levers to sustain the body and aid in locomotion. Eachlong bone is composed of a cylinder, known as the shaft, and two extremities. The shaft is hollow, its wails being thickest in the middle and growing thinner toward the extremities. The extremities are usually considerably enlarged, for convenience of connection with other bones, and to afford a broad surface for the attachment of muscles. The clavical, humerus, radius, ulna, femur, tibia, fibula, the bones of the metacarpus, metatarsus and the phalanges, are classed as long bones.

Where the principal object to be attained is strength, and the motion of the skeleton is limited, the individual bones are short and compressed, as the bones of the carpus and tarsus. The structure of these bones is spongy, except at the surface, where there is a thin crust of compact matter.

Fig. 17. Anatomy of a joint, 1, 1. Bones of a joint. 2, 2. Cartilage. 3, 3, 3, 3. Synovial membrane.

Fig. 18. Anatomy of knee joint. 1. Lower end of thigh-bone. 3. Knee-pan. 2, 4 Ligaments of the knee-pan. 5. Upper end of the tibia, or shin-bone. 6, 12. Cartilages.

When protection is required for the organs of the body, or a broad flat surface for the attachment of the muscles, the bones are expanded into plates, as in the cranium and shoulder-blades.

The irregular or mixed bones are those which, from their peculiar shape, cannot be classed among any of the foregoing divisions. Their structure is similar to the others, consisting of cancellar tissue, surrounded by a crust of compact matter.

The vertebræ, sacrum, coccyx, temporal, sphenoid, ethmoid, malar, two maxillary, palate, inferior turbinated, and hyoid are known as irregular bones.

The formation of the joints requires not only bones, but also [pg 29]cartilages, ligaments, and the synovial membrane, to complete the articulation. Cartilage is a smooth, elastic substance, softer than bone, and invested with a thin membrane, called perichondrium. When cartilage is placed upon convex surfaces, the reverse is true. The Ligaments are white, inelastic, tendinous substances, softer than cartilage, but harder than membrane. Their function is to bind together the bones. The Synovial Membrane covers the cartilages, and is then reflected upon the ligaments, thus forming a thin, closed sac, called the synovial capsule.

All the synovial membranes secrete a lubricating fluid, termed synovia, which enables the surfaces of the bones and ligaments to move freely upon one another. When this fluid is secreted in excessive quantities, it produces a disease known as "dropsy of the joints." There are numerous smaller sacs besides the synovial, called bursæ mucosæ, which in structure are analogous to them, and secrete a similar fluid. Some joints permit motion in every direction, as the shoulders, some in two directions only, as the elbows, while others do not admit of any movement. The bones, ligaments, cartilages, and synovial membrane, are supplied with nerves, arteries, and veins.

When an animal is provided with an internal bony structure, it indicates a high rank in the scale of organization. An elaborate texture of bone is found in no class below the vertebrates. Even in the lower order of this sub-kingdom, which is the highest of animals, bone does not exist, as is the case in some tribes of fishes, such as sharks, etc., and in all classes below that of the cartilaginous fishes, the inflexible substance which sustains the soft parts is either shell or some modification of bone, and is usually found on the outside of the body. True bone, on the contrary, is found in the interior, and, therefore, in higher animals, the skeleton is always internal, while the soft parts are placed external to the bony frame. While many animals of the lowest species, being composed of soft gelatinous matter, are buoyant in water, the highest type of animals requires not only a bony skeleton, but also a flexible, muscular system, for locomotion in the water or upon the land. Each species of the animal kingdom is thus organically adapted to its condition and sphere of life.

[pg 30]

## CHAPTER III.

# PHYSIOLOGICAL ANATOMY.

### THE MUSCLES.

Fig. 19. Muscular fillers highly magnified.

The Muscles are those organs of the body by which motion is produced, and are commonly known as flesh. A muscle is composed of fascieuli, or bundles of fibers, parallel to one another. They are soft, varying in size, of a reddish color, and inclosed in a cellular, membranous sheath. Each fasciculus contains a number of small fibers, which, when subjected to a microscopic examination, are found to consist of fibrillæ, or little fibers; each of these fibrillæ in turn being invested with a delicate sheath. The fibers terminate in a glistening, white tendon, or hard cord, which is attached to the bone. So firmly are they united, that the bone will break before the tendon can be released. When the tendon is spread out, so as to resemble a membrane, it is called fascia. Being of various extent and thickness, it is distributed over the body, as a covering and protection for the more delicate parts, and aids also in motion, by firmly uniting the muscular fibers. The spaces between the muscles are frequently filled with fat, which gives roundness and beauty to the limbs. The muscles are of various forms; some are longitudinal, each extremity terminating in a tendon, which gives them a fusiform or spindle-shaped appearance; others are either fan-shaped, flat, or cylindrical.

[pg 31]

Fig. 20. 1. A spindle-shaped muscle, with tendinous terminations. 2. Fan-shaped muscle. 3. Penniform muscle. 4. Bipenniform muscle.

Fig. 21. Striped muscular fibre showing cleavage in opposite directions. 1. Longitudinal cleavage. 2. Transverse cleavage. 3. Transverse section of disc. 4. Disc nearly detached. 5. Detached disc, showing the sarcous elements. 6. Fibrillæ. 7, 8. Separated fibrillæ highly magnified.

Every muscle has an origin and an insertion. The term origin is applied to the more fixed or central attachment of a muscle, and the term insertion to the movable point to which the force of the muscle is directed; but the origin is not absolutely fixed, except in a small number of muscles, as those of the face, which are attached at one extremity to the bone, and at the other to the movable integument, or skin. In most instances, the muscles may act from either extremity. The muscles are divided into the Voluntary, or muscles of animal life, and the Involuntary, or muscles of organic life. There are, however, some muscles which cannot properly be classified with either, termed Intermediate. The Voluntary Muscles are chiefly controlled by the will, relaxing and contracting at its pleasure, as in the motion of the eyes, mouth, and limbs. The fibers are of a dark red color, and possess great strength. These fibers are parallel, seldom interlacing, but presenting a striped or striated appearance; and a microscopic examination of them shows that even the most minute consist of parallel filaments marked by longitudinal and transverse striæ, or minute channels. The fibers are nearly the same length as the muscles to which they belong. Each muscular fiber is capable of [pg 32]contraction; it may act singly, though usually it acts in unison with others. By a close inspection, it has been found that fibers may be drawn apart longitudinally, in which case they are termed fibrillæ, or they may be separated transversely, forming a series of discs. The Sarcolemma, or investing sheath of the muscles, appears to be formed even before there are any visible traces of the muscle itself. It is a transparent and delicate membrane, but very elastic. The Involuntary Muscles are influenced by the sympathetic nervous system, and their action pertains to the nutritive functions of the body. They differ from the voluntary muscles in not being striated, having no tendons, and in the net-work arrangements of their fibers. The Intermediate Muscles are composed of striated and unstriated fibers; they are, therefore, both voluntary and involuntary in their functions. The muscles employed in respiration are of this class, for we can breathe rapidly or slowly, and, for a short time, even suspend their action; but soon, however, the organic muscles assert their instinctive control, and respiration is resumed.

Fig. 22. Unstriated muscular fiber; at b, in its natural state; at a, showing the nuclei after the action of acetic acid.

Fig. 23. A view of the under side of the diaphragm.

The Diaphragm, or midriff, is the muscular division between the thorax and the abdomen. It has been compared to an inverted basin, the concavity of which is [pg 33][pg 34]directed toward the abdomen. The muscles receive their nourishment from the numerous blood-vessels which penetrate their tissues. The voluntary muscles are abundantly supplied with nerves, while the involuntary are not so numerously furnished. The color of the muscles is chiefly due to the blood which they contain. They vary in size according to their respective functions. For example, the functions of the heart require large and powerful muscles, and those of the eye, small and delicate ones. There are between four hundred and sixty and five hundred muscles in the human body.

Fig. 24. A representation of the superficial layer of muscles on the anterior portion of the body.

Fig. 25. A representation of the superficial layer of muscles on the posterior portion of the body.

Very rarely is motion produced by the action of a single muscle, but by the harmonious action of several. There is infinite variety in the arrangement of the muscles, each being adapted to its purpose, in strength, tenacity, or elasticity. While some involuntarily respond to the wants of organic life, others obey, with mechanical precision, the edicts of the will. The peculiar characteristic of the muscles is their contractility; for example, when the tip of the finger is placed in the ear, an incessant vibration, due to the contraction of the muscles of the ear, can be heard. When the muscles contract, they become shorter; but what is lost in length is gained in breadth and thickness, so that their actual volume remains the same. Muscles alternately contract and relax, and thus act upon the bones. The economy of muscular power thus displayed is truly remarkable. In easy and graceful walking, the forward motion of the limbs is not altogether due to the exercise of muscular power, but partly to the force of gravity, and only a slight assistance of the muscles is required to elevate the leg sufficiently to allow it to oscillate.

Motion is a characteristic of living bodies. This is true, not only in animals, but also in plants. The oyster, although not possessing the power of locomotion, opens and closes its shell at pleasure. The coral insect appears at the door of its cell, and retreats at will. All the varied motions of animals are due to a peculiar property of the muscles, termed contractility. Although plants are influenced by external agents, as light, heat, electricity, etc., yet it is supposed that they may move in response to inward impulses. The sensitive stamens of the barberry, when touched at their base on the inner side, resent the intrusion, by making a sudden jerk forward. Venus's [pg 35][pg 36]fly-trap, a plant found in North Carolina, is remarkable for the sensitiveness of its leaves; which close suddenly and capture insects which chance to alight upon them. The muscles of the articulates are situated within the solid framework, unlike the vertebrates, whose muscles are external to the bony skeleton. All animals have the power of motion, from the lowest radiate to the highest vertebrate, from the most repulsive polyp to that type of organized life made in the very image of God.

The muscles, then, subserve an endless variety of purposes. By their aid the farmer employs his implements of husbandry, the mechanic deftly wields his tools, the artist plies his brush, while the fervid orator gives utterance to thoughts glowing with heavenly emotions. It is by their agency that the sublimest spiritual conceptions can be brought to the sphere of the senses, and the noblest, loftiest aims of to-day can be made glorious realizations of the future.

[pg 37]

## CHAPTER IV.

# PHYSIOLOGICAL ANATOMY.

### THE DIGESTIVE ORGANS.

Digestion signifies the act of separating or distributing, hence its application to the process by which food is made available for nutritive purposes. The organs of digestion are the Mouth, Teeth, Tongue, Salivary Glands, Pharynx, Esophagus, the Stomach and the Intestines, with their glands, the Liver, Pancreas, Lacteals, and the Thoracic Duct.

Fig. 26. A view of the lower jaw. 1. The body. 2, 2. Rami, or branches. 3, 3. Processes of the lower jaw. m. Molar teeth. b. Bicuspids, c. Cuspids. i. Incisors.

The Mouth is an irregular cavity, situated between the upper and the lower jaw, and contains the organs of mastication. It is bounded by the lips in front, by the cheeks at the sides, by the roof of the mouth and teeth of the upper jaw above, and behind and beneath by the teeth of the lower jaw, soft parts, and palate. The soft palate is a sort of pendulum attached only at one of its extremities, while the other involuntarily opens and closes the passage from the mouth to the pharynx. The interior of the mouth, as well as other portions of the alimentary canal, is lined with a delicate tissue, called mucous membrane.

The Teeth are firmly inserted in the alveoli or sockets, of the upper and the lower jaw. The first set, twenty in number, are temporary, and appear during infancy. They are replaced [pg 38]by permanent teeth, of which there are sixteen in each jaw; four incisors, or front teeth, four cuspids, or eye teeth, four bicuspids, or grinders, and four molars, or large grinders. Each tooth is divided into the crown, body, and root. The crown is the grinding surface; the body, the part projecting from the jaw, is the seat of sensation and nutrition; the root is that portion of the tooth which is inserted in the alveolus. The teeth are composed of dentine, or ivory, and enamel. The ivory forms the greater portion of the body and root, while the enamel covers the exposed surface. The small white cords communicating with the teeth are the nerves.

The Tongue is a flat oval organ, the base of which is attached to the os hyoides, while the apex, the most sensitive part of the body, is free. Its surface is covered with a membrane, which, at the sides and lower part, is continuous with the lining of the mouth. On the lower surface of the tongue, this membrane is thin and smooth, but on the upper side it is covered with numerous papillæ, which, in structure, are similar to the sensitive papillæ of the skin.

Fig. 27. The salivary glands. The largest one, near the ear, is the parotid gland. The next below it is the submaxillary gland. The one under the tongue is the sublingual gland.

The Salivary Glands are six in number, three on each side of the mouth. Their function is to secrete a fluid called saliva, which aids in mastication. The largest of these glands, the Parotid, is situated in front and below the ear; its structure, like that of all the salivary glands, is cellular. The Submaxillary gland is circular in form, and situated midway between the [pg 39]angle of the lower jaw and the middle of the chin. The Sublingual is a long flattened gland, and, as its name indicates, is located below the tongue, which when elevated, discloses the saliva issuing from its porous openings.

The Pharynx is nearly four inches in length, formed of muscular and membranous cells, and situated between the base of the cranium and the esophagus, in front of the spinal column. It is narrow at the upper part, distended in the middle, contracting again at its junction with the esophagus. The pharynx communicates with the nose, mouth, larynx, and esophagus.

The Esophagus, a cylindrical organ, is a continuation of the pharynx, and extends through the diaphragm to the stomach. It has three coats: first, the muscular, consisting of an exterior layer of fibers running longitudinally, and an interior layer of transverse fibers; second, the cellular, which is interposed between the muscular and the mucous coat; third, the mucous membrane, or internal coat, which is continuous with the mucous lining of the pharynx.

Fig. 28. A representation of the interior of the stomach. 1. The esophagus. 2. Cardiac orifice opening into the stomach. 6. The middle or muscular coat. 7. The interior or mucous coat. 10. The beginning of the duodenum. 11. The pyloric orifice.

The Stomach is a musculo-membranous, conoidal sac, communicating with the esophagus by means of the cardiac orifice (see Fig. 28). It is situated obliquely with reference to the body, its base lying at the left side, while the apex is directed toward the right side. The stomach is between the liver and spleen, subjacent to the diaphragm, and communicates with the intestinal canal by the pyloric orifice. It has three coats. The peritoneal, or external coat is composed of compact, cellular tissue, woven into a thin, serous membrane, and assists in keeping the stomach in place. The middle coat is formed of three layers of muscular fibers: in the first, the fibres run [pg 40]longitudinally; in the second, in a circular direction; and in the third, they are placed obliquely to the others. The interior, or mucous coat, lines this organ. The stomach has a soft, spongy appearance, and, when not distended, lies in folds. During life, it is ordinarily of a pinkish color. It is provided with numerous small glands, which secrete the gastric fluid necessary for the digestion of food. The lining membrane, when divested of mucus, has a wrinkled appearance. The arteries, veins, and lymphatics, of the stomach are numerous.

Fig. 29. Small and large intestines. 1, 1, 2, 2. Small intestine. 3. Its termination in the large intestine. 4. Appendix vermiformis. 5. Cæcum. 6. Ascending colon. 7. Transverse colon. 8. Descending colon. 9. Sigmoid flexure of colon. 10. Rectum.

The Intestines are those convoluted portions of the alimentary canal into which the food is received after being partially digested, and in which the separation and absorption of the nutritive materials and the removal of the residue take place. The coats of the intestines are analogous to those of the stomach, and are, in fact, only extensions of them. For convenience of description, the intestines may be divided into the small and the large. The small intestine is from twenty to twenty-five feet in length, and consists of the Duodenum, Jejunum, and Ileum. The Duodenum, so called because its length is equal to the breadth of twelve fingers, is the first division of the small intestine. If the mucous membrane of the duodenum be examined, it will be found thrown into numerous folds, which are called valvulæ conniventes, the chief function of which appears to be to retard the course of the alimentary matter, and afford a larger surface for the accommodation of the absorbent vessels. Numerous villi, minute thread-like projections, will be [pg 41]found scattered over the surface of these folds, set side by side, like the pile of velvet. Each villus contains a net-work of blood-vessels, and a lacteal tube, into which the ducts from the liver and pancreas open, and pour their secretions to assist in the conversion of the chyme into chyle. The Jejunum, so named because it is usually found empty after death, is a continuation of the duodenum, and is that portion of the alimentary canal in which the absorption of nutritive matter is chiefly effected. The Ileum, which signifies something rolled up, is the longest division of the small intestine. Although somewhat thinner in texture than the jejunum, yet the difference is scarcely perceptible. The large intestine is about five feet in length, and is divided into the Cæcum, Colon, and Rectum. The Cæcum is about three inches in length. Between the large and the small intestine is a valve, which prevents the return of excrementitious matter that has passed into the large intestine. There is attached to the cæcum an appendage about the size of a goose-quill, and three inches in length, termed the appendix vermiformis. The Colon is that part of the large intestine which extends from the cæcum to the rectum, and which is divided into three parts, distinguished as the ascending, the transverse, and the descending.

Fig. 30. Villi of the small intestine greatly magnified.

Fig. 31. A section of the Ileum, turned inside out, so as to show the appearance and arrangement of the villi on an extended surface.

[pg 42]The Rectum is the terminus of the large intestine. The intestines are abundantly supplied with blood-vessels. The arteries of the small intestine are from fifteen to twenty in number. The large intestine is furnished with three arteries, called the colic arteries. The ileo-colic artery sends branches to the lower part of the ileum, the head of the colon, and the appendix vermiformis. The right colic artery forms arches, from which branches are distributed to the ascending colon. The colica media separates into two branches, one of which is sent to the right portion of the transverse colon, the other to the left. In its course, the superior hemorrhoidal artery divides into two branches, which enter the intestine from behind, and embrace it on all sides, almost to the anus.

The Thoracic Duct is the principal trunk of the absorbent system, and the canal through which much of the chyle and lymph is conveyed to the blood. It begins by a convergence and union of the lymphatics on the lumbar vertebræ, in front of the spinal column, then passes upward through the diaphragm to the lower part of the neck, thence curves forward and downward, opening into the subclavian vein near its junction with the left jugular vein, which leads to the heart.

Fig. 32. c, c. Right and left subclavian veins. b. Inferior vena cava. a. Intestines. d. Entrance of the thoracic duct into the left subclavian vein. 4. Mesenteric glands, through which the lacteals pass to the thoracic duct.

Fig. 33. The inferior surface of the liver. 1. Right lobe. 2. Left lobe. 3. Gall-bladder.

The Liver, which is the largest gland in the body, weighs [pg 43]about four pounds in the adult, and is located chiefly on the right side, immediately below the diaphragm. It is a single organ, of a dark red color, its upper surface being convex, while the lower is concave. It has two large lobes, the right being nearly four times as large as the left. The liver has two coats, the serous, which is a complete investment, with the exception of the diaphragmatic border, and the depression for the gall-bladder, and which helps to suspend and retain the organ in position; and the fibrous, which is the inner coat of the liver, and forms sheaths for the blood-vessels and excretory ducts. The liver is abundantly supplied with arteries, veins, nerves, and lymphatics. Unlike the other glands of the human body, it receives two kinds of blood; the arterial for its nourishment, and the venous, from which it secretes the bile. In the lower surface of the liver is lodged the gall-bladder, a membranous sac, or reservoir, for the bile. This fluid is not absolutely necessary to the digestion of food, since this process is effected by other secretions, nor does bile exert any special action upon, starchy or oleaginous substances, when mixed with them at a temperature of 100° F. Experiments also show that in some animals there is a constant flow of bile, even when no food has been taken, and there is consequently no digestion to be performed. Since the bile is formed from the venous blood, and taken from the waste and disintegration of animal tissue, it would appear that it is chiefly an excrementitious fluid. It does not seem to have accomplished its function when discharged from the liver and poured into the intestine, for there it undergoes various alterations previous to re-absorption, produced by its contact with the intestinal juices. Thus the bile, after being [pg 44]transformed in the intestines, re-enters the blood under a new form, and is carried to some other part of the system to perform its mission.

The Spleen is oval, smooth, convex on its external, and irregularly concave on its internal, surface. It is situated on the left side, in contact with the diaphragm and stomach. It is of a dark red color, slightly tinged with blue at its edges. Some physiologists affirm that no organ receives a greater quantity of blood, according to its size, than the spleen. The structure of the spleen and that of the mesenteric glands are similar, although the former is provided with a scanty supply of lymphatic vessels, and the chyle does not pass through it, as through the mesenteric glands. The Pancreas lies behind the stomach, and extends transversely across the spinal column to the right of the spleen. It is of a pale, pinkish color, and its secretion is analogous to that of the salivary glands; hence it has been called the Abdominal Salivary Gland.

Fig. 34. Digestive organs. 3. The tongue. 7. Parotid gland. 8. Sublingual gland. 5. Esophagus. 9. Stomach. 10. Liver. 11. Gall-bladder, 14. Pancreas. 13, 13. The duodenum. The small and large intestines are represented below the stomach.

Digestion is effected in those cavities which we have described [pg 45]as parts of the alimentary canal. The food is first received into the mouth, where it is masticated by the teeth, and, after being mixed with mucus and saliva, is reduced to a mere pulp; it is then collected by the tongue, which, aided by the voluntary muscles of the throat, carries the food backward into the pharynx, and, by the action of the involuntary muscles of the pharynx and esophagus, is conveyed to the stomach. Here the food is subjected to a peculiar, churning movement, by the alternate relaxation and contraction of the fibers which compose the muscular wall of the stomach. As soon as the food comes in contact with the stomach, its pinkish color changes to a bright red; and from the numerous tubes upon its inner surface is discharged a colorless fluid, called the gastric juice, which mingles with the food and dissolves it. When the food is reduced to a liquid condition, it accumulates in the pyloric portion of the stomach. Some distinguished physiologists believe that the food is kept in a gentle, unceasing, but peculiar motion, called peristaltic, since the stomach contracts in successive circles. In the stomach the food is arranged in a methodical manner. The undigested portion is detained in the upper, or cardiac extremity, near the entrance of the esophagus, by contraction of the circular fibers of the muscular coat. Here it is gradually dissolved, and then carried into the pyloric portion of the stomach. From this, then, it appears, that the dissolved and undissolved portions of food occupy different parts of the stomach. After the food has been dissolved by the gastric fluid, it is converted into a homogeneous, semi-fluid mass, called chyme. This substance passes from the stomach through the pyloric orifice into the duodenum, in which, by mixing with the bile and pancreatic fluid, its chemical properties are again modified, and it is then termed chyle, which has been found to be composed of three distinct parts, a reddish-brown sediment at the bottom, a whey-colored fluid in the middle, and a creamy film at the top. Chyle is different from chyme in two respects: First, the alkali of the digestive fluids, poured into the duodenum, or upper part of the small intestine, neutralizes the acid of the chyme; secondly, both the bile and the pancreatic fluid seem to exert an influence over the fatty substances contained in the chyme, which assists the subdivision of these [pg 46]fats into minute particles. While the chyle is propelled along the small intestine by the peristaltic action, the matter which it contains in solution is absorbed in the usual manner into the vessels of the villi by the process called osmosis. The fatty matters being subdivided into very minute particles, but not dissolved, and consequently incapable of being thus absorbed by osmosis, pass bodily through the epithelial lining of the intestine into the commencement of the lacteal tubes in the villi. The digested substances, as they are thrust along the small intestines, gradually lose their albuminoid, fatty, and soluble starchy and saccharine matters, and pass through the ileo-cæcal valve into the cæcum and large intestine. An acid reaction takes place here, and they acquire the usual fæcal smell and color, which increases as they approach the rectum. Some physiologists have supposed that a second digestion takes place in the upper portion of the large intestine. The lacteals, filled with chyle, pass into the mesenteric glands with which they freely unite, and afterward enter the receptaculum chyli, which is the commencement of the thoracic duct, a tube of the size of a goose-quill, which lies in front of the backbone. The lymphatics, the function of which is to secrete and elaborate lymph, also terminate in the receptaculum chyli, or receptacle for the chyle. From this reservoir the chyle and lymph flow into the thoracic duct, through which they are conveyed to the left subclavian vein, there to be mingled with venous blood. The blood, chyle, and lymph, are then transmitted directly to the lungs.

The process of nutrition aids in the development and growth of the body; hence it has been aptly designated a "perpetual reproduction." It is the process by which every part of the body assimilates portions of the blood distributed to it. In return, the tissues yield a portion of the material which was once a component part of their organization. The body is constantly undergoing waste as well as repair. One of the most interesting facts in regard to the process of nutrition in animals and plants is, that all tissues originate in cells. In the higher types of animals, the blood is the source from which the cells derive their constituents. Although the alimentary canal is more or less complicated in different [pg 47]classes of animals, yet there is no species, however low in the scale of organization, which does not possess it in some form.[2] The little polyp has only one digestive cavity, which is a pouch in the interior of the body. In some animals circulation is not distinct from digestion, in others respiration and digestion are performed by the same organs; but as we rise in the scale of animal life, digestion and circulation are accomplished in separate cavities, and the functions of nutrition become more complex and distinct.

[pg 48]

## CHAPTER V.

# PHYSIOLOGICAL ANATOMY.

### ABSORPTION.

Fig. 35. Villi of the small intestine greatly magnified.

Absorption is the vital function by which nutritive materials are selected and imbibed for the sustenance of the body. Absorption, like all other functional processes, employs agents to effect its purposes, and the villi of the small intestine, with their numberless projecting organs, are specially employed to imbibe fluid substances; this they do with a celerity commensurate to the importance and extent of their duties. They are little vascular prominences of the mucous membrane, arising from the interior surface of the small intestine. Each villus has two sets of vessels. (1.) The blood-vessels, which, by their frequent blending, form a complete net-work beneath the external epithelium; they unite at the base of the villus, forming a minute vein, which is one of the sources of the portal vein. (2.) In the center of the villus is another vessel, with thinner and more transparent walls, which is the commencement of a lacteal.

The Lacteals originate in the walls of the alimentary canal, [pg 49]are very numerous in the small intestine, and, passing between the laminæ of the mesentery, they terminate in the receptaculum chyli, or reservoir for the chyle. The mesentery consists of a double layer of cellular and adipose tissue. It incloses the blood-vessels, lacteals, and nerves of the small intestine, together with its accessory glands. It is joined to the posterior abdominal wall by a narrow root; anteriorly, it is attached to the whole length of the small intestine. The lacteals are known as the absorbents of the intestinal walls, and after digestion is accomplished, are found to contain a white, milky fluid, called chyle. The chyle does not represent the entire product of digestion, but only the fatty substances suspended in a serous fluid.

Formerly, it was supposed that the lacteals were the only agents employed in absorption, but more recent investigations have shown that the blood-vessels participate equally in the process, and are frequently the more active and important of the two. Experiments upon living animals have proved that absorption of poisonous substances occurs, even when all communication by way of the lacteals and lymphatics is obstructed, the passage by the blood-vessels alone remaining. The absorbent power which the blood-vessels of the alimentary canal possess, is not limited to alimentary substances, but through them, soluble matters of almost every description are received into the circulation.

The Lymphatics are not less important organs in the process of absorption. Nearly every part of the body is permeated by a second series of capillaries, closely interlaced with the blood-vessels, collectively termed the Lymphatic System. Their origin is not known, but they appear to form a plexus in the tissues, from which their converging trunks arise. They are composed of minute tubes of delicate membrane, and from their net-work arrangement they successively unite and finally terminate in two main trunks, called the great lymphatic veins. The lymphatics, instead of commencing on the intestinal walls, as do the lacteals, are distributed through most of the vascular tissues as well as the skin. The lymphatic circulation is not unlike that of the blood; its circulatory apparatus is, however, more delicate, and its functions are not so well understood.

[pg 50]

Fig. 36. A general view of the Lymphatic System.

[pg 51]The lymph which circulates through the lymphatic vessels is an alkaline fluid composed of a plasma and corpuscles. It may be considered as blood deprived of its red corpuscles and, diluted with water. Nothing very definite is known respecting the functions of this fluid. A large proportion of its constituents is derived from the blood, and the exact connection of these substances to nutrition is not properly understood. Some excrementitious matters are supposed to be taken from the tissues by the lymph and discharged into the blood, to be ultimately removed from the system. The lymph accordingly exerts an important function by removing a portion of the decayed tissues from the body.

Fig. 37. 1. A representation of a lymphatic vessel highly magnified. 2. Lymphatic valves. 3. A lymphatic gland and its vessels.

In all animals which possess a lacteal system there is also a lymphatic system, the one being the complement of the other. The fact that lymph and chyle are both conveyed into the general current of circulation, leads to the inference that the lymph, as well as the chyle, aids in the process of nutrition. The body is continually undergoing change, and vital action implies waste of tissues, as well as their growth. Those organs which are the instruments of motion, as the muscles, cannot be employed without wear and waste of their component parts. Renovated tissues must replace those which are worn out, and it is a part of the function of the absorbents to convey nutritive material into the general circulation. Researches in microscopical anatomy have shown that the skin contains multitudes of lymphatic vessels and that it is a powerful absorbent.

Absorption is one of the earliest and most essential functions of animal and vegetables tissues. The simpler plants consist of only a few cells, all of which are employed in absorption; but [pg 52]in the flowering plants this function is performed by the roots. It is accomplished on the same general principles in animals, yet it presents more modifications and a greater number of organs than in vegetables. While animals receive their food into a sac, or bag called the stomach, and are provided with absorbent vessels such as nowhere exist in vegetables, plants plunge their absorbent organs into the earth, whence they derive nourishing substances. In the lower order of animals, as in sponges, this function is performed by contiguous cells, in a manner almost as elementary as in plants. In none of the invertebrate animals is there any special absorbent system. Internal absorption is classified by some authors as follows: interstitial, recrementitial, and excrementitial; by others as accidental, venous, and cutaneous. The general cutaneous and mucous surfaces exhale, as well as absorb; thus the skin, by means of its sudoriferous glands, exhales moisture, and is at the same time as before stated, a powerful absorbent. The mucous surface of the lungs is continually throwing off carbonic acid and absorbing oxygen; and through their surface poisons are sometimes taken into the blood. The continual wear and waste to which living tissues are subject, makes necessary the provision of such a system of vessels for conveying away the worn-out materials and supplying the body with new.

[pg 53]

## CHAPTER VI.

# PHYSICAL AND VITAL PROPERTIES OF THE BLOOD.

Fig. 38. Red corpuscles of human blood, represented at a, as they are seen when rather beyond the focus of the microscope; and at b as they appear when, within the focus. Magnified 400 diameters.

Fig. 39. Development of human lymph and chyle-corpuscles into red corpuscles of blood. A. A lymph, or white blood-corpuscle. B. The same in process of conversion into a red corpuscle. C. A lymph-corpuscle with the cell-wall raised up around it by the action of water. D. A lymph-corpuscle, from which the granules have almost disappeared. E. A lymph-corpuscle, acquiring color; a single granule, like a nucleus, remains. F. A red corpuscle fully developed.

Blood is the animal fluid by which the tissues of the body are nourished. This pre-eminently vital fluid permeates every organ, distributes nutritive material to every texture, is essentially modified by respiration, and, finally, is the source of every secretion and excretion. Blood has four constituents: Fibrin, Albumen, Salts (which elements, in solution, form the liquor sanguinis), and the Corpuscles. Microscopical examination shows that the corpuscles are of two kinds, known as the red and the white, the former being by far the more abundant. They are circular in form and have a smooth exterior, and are on an average 1/3200 part of an inch in diameter, and are about one-fourth of that in thickness. Hence more than ten millions of them may lie on a space an inch square. If spread out in thin layers and subjected to transmitted light, they present a slightly yellowish color, but when crowded together and viewed by refracted light, exhibit a deep red color. These blood-corpuscles have been termed discs, and are not, as some have supposed, solid material, but are very nearly fluid. The red corpuscles although [pg 54]subjected to continual movement, have a tendency to approach one another, and when their flattened surfaces come in contact, so firmly do they adhere that they change their shape rather than submit to a separation. If separated, however, they return to their usual form. The colorless corpuscles are larger than the red and differ from them in being extremely irregular in their shape, and in their tendency to adhere to a smooth surface, while the red corpuscles float about and tumble over one another. They are chiefly remarkable for their continual variation in form. The shape of the red corpuscles is only altered by external influences, but the white are constantly undergoing alterations, the result of changes taking place within their own substance. When diluted with water and placed under the microscope they are found to consist of a spheroidal sac, containing a clear or granular fluid and a spheroidal vesicle, which is termed the nucleus. They have been regarded by some physiologists as identical with those of the lymph and chyle. Dr. Carpenter believes that the function of these cells is to convert albumen into fibrin, by the simple process of cell-growth. It is generally believed that the red corpuscles are derived in some way from the colorless. It is supposed that the red corpuscle is merely the nucleus of a colorless corpuscle enlarged, flattened, colored and liberated by the bursting of the wall of its cell. When blood is taken from an artery and allowed to remain at rest, it separates into two parts: a solid mass, called the clot, largely composed of fibrin; and a fluid known as the serum, in which [pg 55]the clot is suspended. This process is termed coagulation. The serum, mostly composed of albumen, is a transparent, straw-colored fluid, having the odor and taste of blood. The whole quantity of blood in the body is estimated on an average to be about one-ninth of its entire weight. The distinctions between the arterial and the venous blood are marked, since in the arterial system the blood is uniformly bright red, and in the venous of a very dark red color The blood-corpuscles contain both oxygen and carbonic acid in solution. When carbonic acid predominates, the blood is dark red; when oxygen, scarlet. In the lungs, the corpuscles give up carbonic acid, and absorb a fresh supply of oxygen, while in the general circulation the oxygen disappears in the process of tissue transformation, and is replaced, in the venous blood, by carbonic acid. The nutritive portions of food are converted into a homogeneous fluid, which pervades every part of the body, is the basis of every tissue, and which is termed the blood. This varies in color and composition in different animals. In the polyp the nutritive fluid is known as chyme, in many mollusks, as well as articulates, it is called chyle, but in vertebrates, it is more highly organized and is called blood. In all the higher animal types it is of a red color, although redness is not one of its essential qualities. Some tribes of animals possess true blood, which is not red; thus the blood of the insect is colorless and transparent; that of the reptile yellowish; in the fish the principle part is without color, but the blood of the bird is deep red. The blood of the mammalia is of a bright scarlet hue. The temperature of the blood varies in different species, as well as in animals of the same species under different physiological conditions; for this reason, some animals are called cold-blooded. Disease also modifies the temperature of the blood; thus in fevers it is generally increased, but in cholera greatly diminished. The blood has been aptly termed the "vital fluid," since there is a constant flow from the heart to the tissues and organs of the body, and a continual return after it has circulated through these parts. Its presence in every part of the body is one of the essential conditions of animal life, and is effected by a special set of organs, called the circulatory organs.

[pg 56]

## CHAPTER VII.

# PHYSIOLOGICAL ANATOMY.

### CIRCULATORY ORGANS.

Having considered the formation of chyle, traced it through the digestive process, seen its transmission into the vena cava, and, finally, its conversion into blood, we shall now describe how it is distributed to every part of the system. This is accomplished through organs which, from the round of duties they perform, are called circulatory. These are the Heart, Arteries, Veins, and Capillaries, which constitute the vascular system.

Within the thorax or chest of the human body, and enclosed within a membranous sac, called the pericardium, is the great force-pump of the system, the heart. This organ, to which all the arteries and veins of the body may be either directly or indirectly traced, is roughly estimated to be equal in size to the closed fist of the individual to whom it belongs.

It has a broad end turned upwards, and a little to the right side, termed its base; and a pointed end called its apex, turned downwards, forwards, and to the left side, and lying beneath a point about an inch to the right of, and below, the left nipple, or just below the fifth rib. Attached to the rest of the body only by the great blood-vessels which issue from and enter it at its base, the heart is the most mobile organ in the economy, being free to move in different directions.

The heart is divided into two great cavities by a fixed partition, which extends from the base to the apex of the organ, and which prevents any direct communication between them. Each of these great cavities is further subdivided transversely [pg 57]by a movable partition, the cavity above each transverse partition being called the auricle, and the cavity below, the ventricle, right or left, as the case may be.

Fig. 40. General view of the heart and lungs, t. Trachea, or windpipe, a. Aorta, p. Pulmonary artery, 1,2. Branches of the pulmonary artery, one going to the right, the other to the left lung. h. The heart.

The walls of the auricles are much thinner than those of the ventricles, and the wall of the right ventricle is much thinner than that of the left, from the fact that the ventricles have more work to perform than the auricles, and the left ventricle more than the right.

In structure, the heart is composed almost entirely of muscular fibers, which are arranged in a very complex and wonderful manner. The outer surface of the heart is covered with the pericardium, which closely adheres to the muscular substance. Inside, the cavities are lined with a thin membrane, called the endocardium. At the junction between the auricles and ventricles, the apertures of communication between their cavities are strengthened by fibrous rings. Attached to these fibrous rings are the movable partitions or valves, between the auricles and the ventricles, the one on the right side of the heart being called the tricuspid valve, and the one on the left side the mitral valve. A number of fine, but strong, tendinous chords, called chordæ tendineæ, connect the edges and apices of these valves with column-like elevations of the fleshy substance of the walls of the ventricles, called columnæ carneæ.

[pg 58]

Fig. 41. 1. The descending vena cava. 2. The ascending vena cava. 3. The right auricle. 4. The opening between the right auricle and the right ventricle. 5. The right ventricle. 6. The tricuspid valves. 7. The pulmonary artery. 8, 8. The branches of the pulmonary artery which pass to the right and the left lung. 9. The semilunar valves of the pulmonary artery. 10. The septum between the two ventricles of the heart. 11, 11. The pulmonary veins. 12. The left auricle. 13. The opening between the left auricle and ventricle. 14. The left ventricle. 15. The mitral valves. 16, 16. The aorta. 17. The semilunar valves of the aorta.

The valves are so arranged that they present no obstacle to the free flow of blood from the auricles into the ventricles, but if any is forced the other way, it gets between the valve and the wall of the heart, and drives the valve backwards and upwards, thus forming a transverse partition between the auricle and ventricle, through which no fluid can pass.

At the base of the heart are given off two large arteries, one on the right side, which conveys the blood to the lungs, called the pulmonary artery, and one on the left side, which conveys the blood to the system in general, called the aorta. At the junction of each of these great vessels with its corresponding ventricle, is another valvular apparatus, consisting of three pouch-like valves, called the semilunar valves, from their resemblance, in shape, to a half-moon. Being placed on a level and meeting in the middle line, they entirely prevent the passage of any fluid which may be forced along the artery towards the heart, but, flapping back, they offer no obstruction to the free flow of blood from the ventricles into the arteries.

Fig. 42. A representation of the venous and arterial circulation of the blood.

The Arteries, being always found empty after death, were supposed by the ancients, who were ignorant of the circulation of the blood, to be tubes containing air; hence their name, which is derived from a Greek word and signifies an air-tube. Arteries are the cylindrical tubes which carry blood to every part of the system. All the arteries, except the coronary [pg 59]which supply the substance of the heart, arise from the two main trunks, the pulmonary artery and the aorta. They are of a yellowish-white color, and their inner surface is smooth. The arteries have three coats. (1.) The external coat, which is destitute of fat, and composed chiefly of cellular tissue, is very firm and elastic, and can readily be dissected from the middle coat. (2.) The middle, or fibrous coat, is thicker than the external, and composed of yellowish fibers, its chief property is contractility. (3.) The internal coat consists of a colorless, thin, transparent membrane, yet so strong that it can, it is thought, better resist a powerful pressure than either of the others. Arteries are very elastic as well as extensible, and their chief extensibility is in length. If an artery of a dead body be divided, although empty, its cylindrical form will be preserved.

The Veins are the vessels through which the venous blood returns to the auricles of the heart. They are more numerous than the arteries, and originate from numerous capillary tubes, while the arteries are given off from main trunks. In some parts of the body, the veins correspond in number to the arteries; while in [pg 60]others, there are two veins to every artery. The veins commence by minute roots in the capillaries, which are everywhere distributed through the body, and gradually increase in size, until they unite and become large trunks, conveying the dark blood to the heart. The veins, like the arteries, have three coats. The external, or cellular coat, resembles that of the arteries; the middle is fibrous, but thinner than the corresponding one of the arteries; and the internal coat is serous, and analogous to that of those vessels. The veins belong to the three following classes: (1.) The systemic veins, which bring the blood from different parts of the body and discharge it into the vena cava, by means of which it is conveyed to the heart; (2), the pulmonary veins, which bring the arterial, or bright red blood from the lungs and carry it to the left auricle; (3), the veins of the portal system, which originate in the capillaries of the abdominal organs, then converge into trunks and enter the liver, to branch off again into divisions and subdivisions of the minutest character.

The Capillaries form an extremely fine net-work, and are distributed to every part of the body. They vary in diameter from 1/3500 to 1/2000 of an inch. They are so universally prevalent throughout the skin, that the puncture of a needle would wound a large number of them. These vessels receive the blood and bring it into intimate contact with the tissues, which take from it the principal part of its oxygen and other elements, and give up to it carbonic acid and the other waste products resulting from the transformation of the tissues, which are transmitted through the veins to the heart, and thence by the arteries to the lungs and various excretory organs.

The blood from the system in general, except the lungs, is poured into the right auricle by two large veins, called the superior and the inferior vena cava,' and that returning from the lungs is poured into the left auricle by the pulmonary veins.

During life the heart contracts rhythmically, the contractions commencing at the base, in each auricle, and extending towards the apex.

Now it follows, from the anatomical arrangement of this [pg 61]organ, that when the auricles contract, the blood contained in them is forced through the auriculo-ventricular openings into the ventricles; the contractions then extending to the ventricles, in a wave-like manner, the great proportion of the blood, being prevented from re-entering the auricles by the tricuspid and mitral valves, is forced onward into the pulmonary artery from the right ventricle, and into the aorta from the left ventricle.

When the contents of the ventricles are suddenly forced into these great blood-vessels, a shock is given to the entire mass of fluid which they contain, and this shock is speedily propagated along their branches, being known at the wrist as the pulse.

On inspection, between the fifth and sixth ribs on the left side of the chest, a movement is perceptible, and, if the hand be applied, the impulse may be felt. This is known as the throbbing, or beating of the heart.

If the ear is placed over the region of the heart, certain sounds are heard, which recur with great regularity. First is heard a comparatively long, dull sound, then a short, sharp sound, then a pause, and then the long, dull sound again. The first sound is caused mainly by the tricuspid and mitral valves, and the second is the result of sudden closure of the semilunar valves.

No language can adequately describe the beauty of the circulatory system. The constant vital flow through the larger vessels, and the incessant activity of those so minute that they are almost imperceptible, fully illustrate the perfectness of the mechanism of the human body, and the wisdom and goodness of Him who is its author.

Experiments have shown that the small arteries may be directly influenced through the nervous system, which regulates their caliber by controlling the state of contraction of their muscular walls. The effect of this influence of the nervous system enables it to control the circulation over certain areas; and, notwithstanding the force of the heart and the state of the blood-vessels in general, to materially modify the circulation in different spots. Blushing, which is simply a local modification of the circulation, is effected in this way. Some emotion takes possession of the mind, and the action of the nerves, which ordinarily keep up a moderate contraction of [pg 62]the muscular coats of the arteries, is lost, and the vessels relax and become distended with arterial blood, which is a warm and bright red fluid; thereupon a burning sensation is felt, and the skin grows red, the degree of the blush depending upon the intensity of the emotion.

The pallor produced by fright and by extreme anxiety, is purely the result of a local modification of the circulation, brought about by an over-stimulation of the nerves which supply the small arteries, causing them to contract, and to thus cut off more or less completely the supply of blood.

[pg 63]

## CHAPTER VIII.

# PHYSIOLOGICAL ANATOMY.

### THE ORGANS OF RESPIRATION.

The Organs of Respiration are the Trachea, or windpipe, the Bronchia, formed by the subdivision of the trachea, and the Lungs, with their air-cells. The Trachea is a vertical tube situated between the lungs below, and a short quadrangular cavity above, called the larynx, which is part of the windpipe, and used for the purpose of modulating the voice in speaking or singing. In the adult, the trachea, in its unextended state, is from four and one-half to five inches in length, about one inch in diameter, and, like the larynx, is more fully developed in the male than in the female. It is a fibro-cartilaginous structure, and is composed of flattened rings, or segments of circles. It permits the free passage of air to and from the lungs.

The Bronchia are two tubes, or branches, one proceeding from the windpipe to each lung. Upon entering the lungs, they divide and subdivide until, finally, they terminate in small cells, called the bronchial or air-cells, which are of a membranous character.

Fig. 43. An ideal representation of the respiratory organs. 3. The larynx. 4. The trachea. 5, 6. The bronchia. 9, 9, 9, 9. Air-cells. 1, 1, 1, 2, 2, 2. Outlines of the lungs.

The Lungs are irregular conical organs rounded at the apex, situated within the chest, and filling the greater part of it, since the heart is the only other organ which occupies much space in the thoracic cavity. The lungs are convex externally, and conform to the cavity of the chest, while the internal surface is concave for the accommodation of the heart. The size of the lungs depends upon the capacity of the chest. Their [pg 64]color varies, being of a pinkish hue in childhood but of a gray, mottled appearance in the adult. They are termed the right and left lung. Each lung resembles a cone with its base resting upon the diaphragm, and its apex behind the collar-bone. The right lung is larger though shorter, than the left, not extending so low, and has three lobes, formed by deep fissures, or longitudinal divisions, while the left has but two lobes. Each lobe is also made up of numerous lobules, or small lobes, connected by cellular tissue, and these contain great numbers of cells. The lungs are abundantly supplied with blood-vessels, lymphatics, and nerves. The density of a lung depends upon the amount of air which it contains. Thus, experiment has shown that in a foetus which has never breathed, the lungs are compact and will sink in water; but as soon as they become inflated with air, they spread over a larger surface, and are therefore more buoyant. Each lung is invested, as far as its root, with a membrane, called the pleura, which is then continuously extended to the cavity of the chest, thus performing the double office of lining it, and constituting a partition between the lungs. The part [pg 65]of the membrane which forms this partition is termed the mediastinum. Inflammation of this membrane is called pleurisy. The lungs are held in position by the root, which is formed by the pulmonary arteries, veins, nerves, and the bronchial tubes. Respiration is the function by which the venous blood, conveyed to the lungs by the pulmonary artery, is converted into arterial blood. This is effected by the elimination of carbonic acid, which is expired or exhaled from the lungs, and by the absorption of oxygen from the air which is taken into the lungs, by the act of inspiration or inhalation. The act of expiration is performed chiefly by the elevation of the diaphragm and the descent of the ribs, and inspiration is principally effected by the descent of the diaphragm and the elevation of the ribs.

Fig. 44. A representation of the heart and lungs. 4. The heart. 5. The pulmonary artery. 8. Aorta. 9, 11. Upper lobes of the lungs. 10, 13. Lower lobes. 12. Middle lobe of the right lung. 2. Superior vena cava. 3. Inferior vena cava.

When the muscles of some portions of the air-passages are relaxed, a peculiar vibration follows, known as snoring. Coughing and sneezing are sudden and spasmodic expiratory efforts, and generally involuntary. Sighing is a prolonged deep inspiration, followed by a rapid, and generally audible expiration. It is remarkable that laughing and sobbing, although indicating opposite states of the mind, are produced in very nearly the same manner. In hiccough, the contraction is more sudden and spasmodic than in laughing or sobbing. The quantity of oxygen consumed during sleep is estimated to be considerably less than that consumed during wakefulness.

Fig. 45. View of the pulmonary circulation.

It is difficult to estimate the amount of air taken into the [pg 66]lungs at each inspiration, as the quantity varies according to the condition, size, and expansibility of the chest, but in ordinary breathing it is supposed to be from twenty to thirty cubic inches. The consumption of oxygen is greater when the temperature is low, and during digestion. All the respiratory movements, so far as they are independent of the will of the individual, are controlled by that part of the brain called the medulla oblongata. The respiratory, or breathing process, is not instituted for the benefit of man alone, for we find it both in the lower order of animals and in plant life. Nature is very economical in the arrangement of her plans, since the carbonic acid, which is useless to man, is indispensable to the existence of plants, and the oxygen, rejected by them, is appropriated to his use. In the lower order of animals, the respiratory act is similar to that of the higher types, though not so complex; for there are no organs of respiration, as the lungs and gills are called. Thus, the higher the animal type, the more complex its organism. The effect of air upon the color of the blood is very noticeable. If a quantity be drawn from the body, thus being brought into contact with the air, its color gradually changes to a brighter hue. There is a marked difference between the properties of the venous and the arterial blood.

[pg 67]The venous blood is carried, as we have previously described, to the right side of the heart and to the lungs, where it is converted into arterial blood. It is now of uniform quality, ready to be distributed throughout the body, and capable of sustaining life and nourishing the tissues. Man breathes by means of lungs; but who can understand their wonderful mechanism, so perfect in all its parts? Though every organ is subservient to another, yet each has its own office to perform. The minute air-cells are for the aeration of the blood; the larger bronchial tubes ramify the lungs, and suffuse them with air; the trachea serves as a passage for the air to and from the lungs, while at its upper extremity is the larynx, which has been fitly called the organ of the human voice. At its extremity we find a sort of shield, called the epiglottis, the office of which is supposed to be to prevent the intrusion of foreign bodies.

[pg 68]

## CHAPTER IX.

# PHYSIOLOGICAL ANATOMY

### THE SKIN.

Through digestion and respiration, the blood is continually supplied with material for its renewal; and, while the nutritive constituents of the food are retained to promote the growth of the body, those which are useless or injurious are in various ways expelled. There are, perhaps, few parts of the body more actively concerned in this removal than the skin.

Fig. 46: An ideal view of the papillæ. 1, 1. Cutis vera. 2, 2. Papillary layer. 3, 3. Arteries of the papillæ. 4, 4. Nerves of the papillæ. 5, 5. Veins of the papillæ.

The skin is a membranous envelope covering the entire body. It consists of two layers, termed the Cutis Vera, or true skin, and the Epidermis, or cuticle. The Cutis Vera is composed of fibers similar to those of the cellular tissue. It consists of white and yellow fibers, which are more densely woven near the surface than deeper in the structure; the white give strength, the yellow [pg 69]strength and elasticity combined. The true skin may be divided into two layers, differing in their characteristics, and termed respectively the superficial or papillary layer, and the deep or fibrous layer. Upon the external surface, are little conical prominences, known as papillæ. The papillæ are irregularly distributed over the body, in some parts being smaller and more numerous than in others, as on the finger-ends, where their summits are so intimately connected as to form a tolerably smooth surface. It is owing to their perfect development, that the finger-tips are adapted to receive the most delicate impressions of touch. Although every part of the skin is sensitive, yet the papillæ are extremely so, for they are the principal means through which the impressions of objects are communicated. Each papilla not only contains a minute vein and artery, but it also incloses a loop of sensitive nerves. When the body is exposed to cold, these papillæ can be more distinctly seen in the form of prominences, commonly known as "goose-pimples."

Fig. 47. A section of the skin, showing its arteries and veins. A, A. Arterial branches. B, B. Capillaries in which the branches terminate. C. The venous trunk into which the blood from the capillaries flows.

The internal, or fibrous layer of the skin, contains numerous depressions, each of which furnishes a receptacle for fat. While the skin is supplied with a complete net-work of arteries, veins, and nerves, which make it sensitive to the slightest touch, it also contains numerous lymphatic vessels, so minute that they are invisible to the naked eye.

Among the agents adapted for expelling the excretions from the system, few surpass the Sudoriferous Glands. These are minute organs which wind in and out over the whole extent of the true skin, and secrete the perspiration. Though much [pg 70]of it passes off as insensible transpiration, yet it often accumulates in drops of sweat, during long-continued exercise or exposure to a high temperature. The office of the perspiration is two-fold. It removes noxious matter from the system, and diminishes animal heat, and thereby equalizes the temperature of the body. It also renders the skin soft and pliable, thus better adapting it to the movements of the muscles. The Sebaceous Glands, which are placed in the true skin, are less abundant where the sudoriferous glands are most numerous, and vice versa. Here, as elsewhere, nature acts with systematic and intelligent design. The perspiratory glands are distributed where they are most needed,—in the eyelids, serving as lubricators; in the ear passages, to produce the cerumen, or wax, which prevents the intrusion of small insects; and in the scalp, to supply the hair with its natural pomatum.

Fig. 48. A perspiratory gland, highly magnified. 1, 1. The gland. 2, 2. Excretory ducts uniting to form a tube which tortuously perforates the cuticle at 3, and opens obliquely on its surface at 4.

Fig. 49. A representation of oil-tubes from the scalp and nose.

Fig. 50. Anatomy of the skin. 5, 5. Cutis vera (true skin). 4, 4. Nervous tissue. 3, 3. Sensitive layer in which are seen the nerves. 2, 2. The layer containing pigment cells. 1, 1. Epidermis (cuticle).

The Epidermis, or Cuticle, so called because it is placed upon the skin, is the outer layer of the skin. Since it is entirely destitute of nerves and blood-vessels, it is not sensitive. Like the cutis vera, it has two surfaces composed of layers. The internal, or Rete Mucosum, which is made up chiefly of pigment cells, is adapted to the irregularities of the cutis vera, and sends prolongations into all its glandular follicles. The external surface, or epidermis proper, is elastic, destitute of coloring matter, and consists of mere [pg 71]horny scales. As soon as dry, they are removed in the form of scurf, and replaced by new ones from the cutis vera. These scales may be removed by a wet-sheet pack, or by friction. The cuticle is constantly undergoing renewal. This layer serves to cover and protect the nervous tissue of the true skin beneath. We may here observe that the cuticle contains the pigment for coloring the skin. In dark races, as the negro, the cuticle is very thick and filled with black pigment. The radiation of animal heat is dependent upon the thickness and color of this cuticle. Thus, in the dark races, the pigment cells are most numerous, and in proportion as the skin is dark or fair do we find these cells in greater or lesser abundance. The skin of the Albino is of pearly whiteness, devoid even of the pink or brown tint which that of the European always possesses. This peculiarity must be attributed to the absence of pigment cells [pg 72]which, when present, always present a more or less dark color. The theory that climate alone is capable of producing all these diversities is simply absurd. The Esquimaux, who live in Greenland and the arctic regions of America, are remarkable for the darkness of their complexion. Humboldt remarks that the American tribes of the tropical regions have no darker skin than the mountaineers of the temperate zone. Climate may modify the complexion, but it cannot make it.

Fig. 51. Structure of the human hair. A. External surface of the shaft, showing the transverse striæ and jagged boundary, caused by the imbrications of the scaly cortex. B. Longitudinal section of the shaft, showing the fibrous character of the medullary substance, and the arrangement of the pigmentary matter. C. Transverse sections, showing the distinction between the cortical and medullary substances, and the central collection of pigmentary matter, sometimes found in the latter. Magnified 310 diameters.

Hairs are horny appendages of the skin, and, with the exception of the hands, the soles of the feet, the backs of the fingers and toes, between the last joint and the nail, and the upper eyelids, are distributed more or less abundantly over every part of the surface of the body. Over the greater part of the surface the hairs are very minute, and in some places are not actually apparent above the level of the skin; but the hair of the head, when permitted to reach its full growth, attains a length of from twenty inches to a yard, and, in rare instances, even six feet. A hair may be divided into a middle portion, or shaft, and two extremities; a peripheral extremity, called the point; and a central extremity, inclosed within [pg 73]the hair sac, or follicle, termed the root. The root is somewhat greater in diameter than the shaft, and cylindrical in form, while its lower part expands into an oval mass, called the bulb. The shaft of the hair is not often perfectly cylindrical, but is more or less flattened, which circumstance gives rise to waving and curling hair; and, when the flattening is spiral in direction, the curling will be very great. A hair is composed of three different layers of cell-tissues: a loose, cellulated substance, which occupies its center, and constitutes the medulla, or pith; the fibrous tissue, which incloses the medulla, and forms the chief bulk of the hair; and a thin layer, which envelops this fibrous structure, and forms the smooth surface of the hair. The medulla is absent in the downy hairs, but in the coarser class it is always present, especially in white hair. The color of hair is due partly to the granules and partly to an inter-granular substance, which occupies the interstices of the granules and the fibers. The quantity of hair varies according to the proximity and condition of the follicles. The average number of hairs of the head may be stated at 1,000 in a superficial square inch; and, as the surface of the scalp has an area of about one hundred and twenty superficial square inches, the average number of hairs on the entire head is 120,000. The hair possesses great durability, as is evinced by its endurance of chemical processes, and by its discovery, in the tombs of mummies more than two thousand years old. The hair is remarkable for its elasticity and strength. Hair is found to differ materially from horn in its chemical composition. According to Vauquelin, its constituents are animal matter, a greenish-black oil, a white, concrete oil, phosphate of lime, a trace of carbonate of lime, oxide of manganese, iron, sulphur, and silex. Red hair contains a reddish oil, a large proportion of sulphur, and a small quantity of iron. White hair contains a white oil, and phosphate of magnesia. It has been supposed that hair grows after death, but this theory was probably due to the lengthening of the hair by the absorption of moisture from the body or atmosphere.

The nails constitute another class of appendages of the skin. They consist of thin plates of horny tissue, having a [pg 74]root, a body, and a free extremity. The root, as well as the lateral portion, is implanted in the skin, and has a thin margin which is received into a groove of the true skin. The under surface is furrowed, while the upper is comparatively smooth. The nails grow in the same manner as the cuticle.

[pg 75]

## CHAPTER X.

# PHYSIOLOGICAL ANATOMY.

### SECRETION.

The term Secretion, in its broadest sense, is applied to that process by which substances are separated from the blood, either for the reparation of the tissues or for excretion. In the animal kingdom this process is less complicated than in vegetables. In the former it is really a separation of nutritive material from the blood. The process, when effected for the removal of effete matter, is, in a measure, chemical, and accordingly the change is greater.

Three elementary constituents are observed in secretory organs: the cells, a basement membrane, and the blood-vessels. Obviously, the most essential part is the cell.

The physical condition necessary for the healthy action of the secretory organs is a copious supply of blood, in which the nutritive materials are abundant. The nervous system also influences the process of secretion to a great extent. Intense emotion will produce tears, and the sight of some favorite fruit will generally increase the flow of saliva.

The process of secretion depends upon the anatomical and chemical constitution of the cell-tissues. The principal secretions are (1), Perspiration; (2), Tears; (3), Sebaceous matter; (4), Mucus; (5), Saliva; (6), Gastric juice; (7), Intestinal juice; (8), Pancreatic juice; (9), Bile; (10), Milk.

Perspiration is a watery fluid secreted in minute glands, which are situated in every part of the skin, but are more numerous on the anterior surfaces of the body. Long thread-like tubes, only 1/100th of an inch in diameter, lined with [pg 76]epithelium, penetrate the skin, and terminate in rounded coils, enveloped by a net-work of capillaries, which supply the secretory glands with blood. It is estimated by Krause that the entire number of perspiratory glands is two million three hundred and eighty-one thousand two hundred and forty-eight, and the length of each glandular coil being 1/16 of an inch, we may estimate the length of tubing to be not less than two miles and a third. This secretion has a specific gravity of 1003.5, and, according to Dr. Dalton, is composed of

Water, | 995.50
Chloride of Sodium, | 2.23
Chloride of Potassium, | 0.24
Sulphate of Soda and Potassa, | 0.01
Salts of organic acids, with Soda and Potassa, | 2.02
| ————
| 1000.00

Traces of organic matter, mingled with a free volatile acid, are also found in the perspiration. It is the acid which imparts to this secretion its peculiar odor, and acid reaction. The process of its secretion is continuous, but, like all bodily functions, it is subject to influences which augment or retard its activity. If, as is usually the case when the body is in a state of repose, evaporation prevents its appearance in the liquid form, it is called invisible or insensible perspiration. When there is unusual muscular activity, it collects upon the skin, and is known as sensible perspiration. This secretion performs an important office in the animal economy, by maintaining the internal temperature at about 100° Fahr. Even in the Arctic regions, where the explorer has to adapt himself to a temperature of 40° to 80° below zero, the generation of heat in the body prevents the internal temperature from falling below this standard. On the contrary, if the circulation is quickened by muscular exertion, the warmer blood flowing from the internal organs into the capillaries, raises the temperature of the skin, secretion is augmented, the moisture exudes from the pores, and perceptible evaporation begins. A large portion of the animal heat is thrown off in this process, and the temperature of the skin is reduced. A very warm, dry atmosphere can be borne with impunity but if moisture is [pg 77]introduced, evaporation ceases, and the life of the animal is endangered. Persons have been known to remain in a temperature of about 300° Fahr. for some minutes without unpleasant effects. Three conditions may be assigned as effective causes in retarding or augmenting this cutaneous secretion, variations in the temperature of the atmosphere, muscular activity, and influences which affect the nerves. The emotions exert a remarkable influence upon the action of the perspiratory glands. Intense fear causes great drops of perspiration to accumulate on the skin, while the salivary glands remain inactive.

Tears. The lachrymal glands are small lobular organs, situated at the outer and upper orbit of the eye, and have from six to eight ducts, which open upon the conjunctiva, between the eyelid and its inner fold. This secretion is an alkaline, watery fluid. According to Dr. Dalton, its composition is as follows:

Water, | 882.0
Albuminous matter, | 5.0
Chloride of Sodium, | 13.0
Mineral Salts, a trace,
| ————
| 1000.0

The function of this secretion is to preserve the brilliancy of the eye. The tears are spread over this organ by the reflex movement of the eyelid, called winking, and then collected in the puncta lachrymalia and discharged into the nasal passage. This process is constant during life. The effect of its repression is seen in the dim appearance of the eye after death. Grief or excessive laughter usually excite these glands until there is an overflow.

Sebaceous Matter. Three varieties of this secretion are found in the body. A product of the sebaceous glands of the skin is found in those parts of the body which are covered with hairs; also, on the face and the external surface of the organs of generation. The sebaceous glands consist of a group of flask-shaped cavities, opening into a common excretory duct. Their secretion serves to lubricate the hair and soften the skin. The ceruminous glands of the external auditory meatus, or [pg 78]outer opening of the ear, are long tubes terminating in a glandular coil, within which is secreted the glutinous matter of the ear. This secretion serves the double purpose of moistening the outer surface of the membrana tympani, or ear-drum, and, by its strong odor, of preventing the intrusion of insects. The Meibomian glands are arranged in the form of clusters along the excretory duct, which opens just behind the roots of the eyelashes. The oily nature of this secretion prevents the tears, when not stimulated by emotion, from overflowing the lachrymal canal.

Mucus. The mucous membranes are provided with minute glands which secrete a viscid, gelatinous matter, called mucus. The peculiar animal matter which it contains is termed mucosin. These glands are most numerous in the Pharynx, Esophagus, Trachea, Bronchia, Vagina and Urethra. They consist of a group of secreting sacs, terminating at one extremity in a closed tube, while the other opens into a common duct. The mucus varies in composition in different parts of the body; but in all, it contains a small portion of insoluble animal matter. Its functions are threefold. It lubricates the membranes, prevents their injury, and facilitates the passage of food through the alimentary canal.

Saliva. This term is given to the first of the digestive fluids, which is secreted in the glands of the mouth. It is a viscid, alkaline liquid, with a specific gravity of about 1005. If allowed to stand, a whitish precipitate is formed. Examinations with the microscope show it to be composed of minute, granular cells and oil globules, mingled with numerous scales of epithelium. According to Bidder and Schmidt, the composition of saliva is as follows:

Water, | 995.16
Organic matter, | 1.34
Sulpho-cyanide of Potassium, | 0.06
Phosphates of Sodium, Calcium and Magnesium, | .98
Chlorides of Sodium and Potassium, | .84
Mixture of Epithelium, | 1.62
| 1000.00

Two kinds of organic matter are present in the saliva; one, termed ptyalin, imparts to the saliva its viscidity, and it [pg 79]obtained from the secretions of the parotid, submaxillary and sublingual glands; another, which is not glutinous, is distinguished by the property of coagulating when subjected to heat. The saliva is composed of four elementary secretions, derived respectively, from the mucous follicles of the mouth, and the parotid, the submaxillary, and the sublingual glands. The process of its secretion is constant, but is greatly augmented by the contact of food with the lining membrane. The saliva serves to moisten the triturated food, facilitate its passage, and has the property of converting starch into sugar; but the latter quality is counteracted by the action of the gastric juice of the stomach.

Gastric Juice. The minute tubes, or follicles, situated in the mucous membrane of the stomach, secrete a colorless, acid liquid, termed the gastric juice. This fluid appears to consist of little more than water, containing a few saline matters in solution, and a small quantity of free hydrochloric acid, which gives it an acid reaction. In addition to these, however, it contains a small quantity of a peculiar organic substance, termed pepsin, which in chemical composition, is very similar to ptyalin, although it is very different in its effects. When food is introduced into the stomach, the peristaltic contractions of that organ roll it about, and mingle it with the gastric juice, which disintegrates the connective tissue, and converts the albuminous portions into the substance called chyme, which is about the consistency of pea-soup, and which is readily absorbed through the animal membranes into the blood of the delicate and numerous vessels of the stomach, whence it is conveyed to the portal vein and to the liver. The secretion of the gastric juice is influenced by nervous conditions. Excess of joy or grief effectually retard or even arrest its flow.

Intestinal Juice. In the small intestine, a secretion is found which is termed the intestinal juice. It is the product of two classes of glands situated in the mucous membrane, and termed respectively, the follicles of Lieberkuhn and the glands of Brunner. The former consist of numerous small tubes, lined with epithelium, which secrete by far the greater portion of this fluid. The latter are clusters of round follicles [pg 80]opening into a common excretory duct. These sacs are composed of delicate, membranous tissue, having numerous nuclei on their walls. The difficulty of obtaining this juice for experiment is obvious, and therefore its chemical composition and physical properties are not known. The intestinal juice resembles the secretion of the mucous follicles of the mouth, being colorless, vitreous in appearance, and having an alkaline reaction.

Pancreatic Juice. This is a colorless fluid, secreted in a lobular gland which is situated behind the stomach, and runs transversely from the spleen across the vertebral column to the duodenum. The most important constituent of the pancreatic juice is an organic substance, termed pancreatin.

The Bile. The blood which is collected by the veins of the stomach, pancreas, spleen, and intestines, is discharged into a large trunk called the portal vein, which enters the liver. This organ also receives arterial blood from a vessel called the hepatic artery, which is given off from the aorta below the diaphragm. If the branches of the portal vein and hepatic artery be traced into the substance of the liver, they will be found to accompany one another, and to subdivide, becoming smaller and smaller. Finally, the portal vein and hepatic artery will be found to terminate in capillaries which permeate the smallest perceptible subdivisions of the liver substance, which are polygonal masses of not more than one-tenth of an inch in diameter, called the lobules. Every lobule rests upon one of the ramifications of a great vessel termed the hepatic vein, which empties into the inferior vena cava. There is also a vessel termed the hepatic duct leading from the liver, the minute subdivisions of which penetrate every portion of the substance of that organ. Connected with the hepatic duct, is the duct of a large oval sac, called the gall-bladder.

Each lobule of the liver is composed of minute cellular bodies known as the hepatic cells. It is supposed that in these cells the blood is deprived of certain materials which are converted into bile. This secretion is a glutinous fluid, varying in color from a dark golden brown to a bright yellow, has a specific gravity ranging from 1018 to 1036, and a [pg 81]slightly alkaline reaction. When agitated, it has a frothy appearance. Physiologists have experienced much difficulty in studying the character of this secretion from the instability of its constituents when subjected to chemical examination.

Fig. 52. Section of the Liver, showing the ramifications of the portal vein. 1. Twig of portal vein. 2, 2', 2", 2"'. Interlobular vein. 3, 3', 3", Lobules.

Biliverdin is an organic substance peculiar to the bile, which imparts to that secretion its color. When this constituent is re-absorbed by the blood and circulates through the tissues, the skin assumes a bright yellow hue, causing what is known as the jaundice. Cholesterin is an inflammable crystallizable substance soluble in alcohol or ether. It is found in the spleen and all the nervous tissues. It is highly probable that it exists in the blood, in some state or combination, and assumes a crystalline form only when acted upon by other substances or elements. Two other constituents, more important than either of the above, are collectively termed biliary salts. These elements were discovered in 1848, by Strecker, who termed them glycocholate and taurocholate of soda. Both are crystalline, resinous substances, and, although resembling each other in many respects, the chemist may distinguish them by their reaction, for both yield a precipitate if treated with subacetate of lead, but only the glycocholate will give a precipitate with acetate of lead. In testing for biliary substances, the most satisfactory method is the one proposed by Pettenkoffer. A solution of cane-sugar, one part of sugar to four parts of water, is mixed with the suspected substance. Dilute sulphuric acid is then added until a white precipitate falls, which is re-dissolved in an excess of the acid. On the addition of more sulphuric acid, it becomes opalescent, and passes through the successive hues of scarlet, lake, and a rich purple. Careful experiments have proved [pg 82]that it is a constant secretion; but its flow is mere abundant during digestion. During the passage through the intestines it disappears. It is not eliminated, and Pettenkoffer's test has failed to detect its existence in the portal vein. These facts lead physiologists to the conclusion, that it undergoes some transformation in the intestines and is re-absorbed.

After digestion has been going on in the stomach for some time, the semi-digested food, in the form of chyme, begins to pass through the pyloric orifice of the stomach into the duodenum, or upper portion of the small intestine. Here it encounters the intestinal juice, pancreatic juice, and the bile, the secretion of all of which is stimulated by the presence of food in the alimentary tract. These fluids, mingling with the chyme, give it an alkaline reaction, and convert it into chyle. The transformation of starch into sugar, which is almost, if not entirely, suspended while the food remains in the stomach, owing to the acidity of the chyme, is resumed in the duodenum, the acid of the chyme, being neutralized by the alkaline secretions there encountered.

Late researches have demonstrated that the pancreatic juice exerts a powerful effect on albuminous matters, not unlike that of the gastric juice.

Thus, it seems that while in the mouth only starchy, and while in the stomach only albuminous substances are digested, in the small intestine all kinds of food materials, starchy, albuminoid, fatty and mineral, are either completely dissolved, or minutely subdivided, and so prepared that they may be readily absorbed through the animal membranes into the vessels.

Milk. The milk is a white, opaque fluid, secreted in the lacteal glands of the female, in the mammalia. These glands consist of numerous follicles, grouped around an excretory duct, which unites with similar ducts coming from other lobules. By successive unions, they form large branches, termed the lactiferous ducts, which open by ten to fourteen minute orifices on the extremity of the nipple. The most important constituent of milk is casein; it also contains oily and saccharine substances. This secretion, more than any other, as influenced by nervous conditions. A mother's bosom will [pg 83]fill with milk at the thought of her infant child. Milk is sometimes poisoned by a fit of ill-temper, and the infant made sick and occasionally thrown into convulsions, which in some instances prove fatal. Sir Astley Cooper mentions two cases in which terror instantaneously and permanently arrested this secretion. It is also affected by the food and drink. Malt liquors and other mild alcoholic beverages temporarily increase the amount of the secretion, and may, in rare instances, have a beneficial effect upon the mother. They sometimes affect the child, however, and their use is not to be recommended unless the mother is extremely debilitated, and there is a deficiency of milk.

[pg 84]

## CHAPTER XI.

# PHYSIOLOGICAL ANATOMY.

### EXCRETION.

The products resulting from the waste of the tissues are constantly being poured into the blood, and, as we have seen, the blood being everywhere full of corpuscles, which, like all living things, die and decay, the products of their decomposition accumulate in every part of the circulatory system. Hence, if the blood is to be kept pure, the waste materials incessantly poured into this fluid, or generated in it, must be as continually removed, or excreted. The principal sets of organs concerned in effecting the separation of excrementitious substances from the blood are the lungs, the skin, and the kidneys.

The elimination of carbonic acid through the lungs has already been described on page 66, and the excretory function of the skin on page 70.

Fig. 53. View of the kidneys, ureters, and bladder.

The kidneys are two bean-shaped organs, placed at the back of the abdominal cavity, in the region of the loins, one on each side of the spine. The convex side of each kidney is directed outwards, and the concave side is turned inwards towards the spine. From the middle of the concave side, which is termed the hilus, a long tube of small caliber, called the ureter, proceeds to the bladder. The latter organ is an oval bag, situated in the pelvic cavity. It is composed principally of elastic muscular fibers, and is lined internally with mucous membrane, and coated externally with a layer of the peritoneum, the serous membrane which lines the abdominal [pg 85]and pelvic cavities. The ureters enter the bladder through its posterior and lower wall, at some little distance from each other. The openings through which the ureters enter the bladder are oblique, hence it is much easier for the secretion [pg 86]of the kidneys to pass from the ureters into the bladder than for it to get the other way. Leading from the bladder to the exterior of the body is a tube, called the urethra, through which the urine is voided.

The excretion of the kidneys, termed the urine, is an amber-colored or straw-colored fluid, naturally having a slightly acid reaction, and a specific gravity ranging from 1,015 to 1,025. Its principal constituents are urea and uric acid, together with various other animal matters of less importance, and saline substances, held in solution in a proportionately large amount of water. The composition of the urine and the quantity excreted vary considerably, being influenced by the moisture and temperature of the atmosphere, by the character of the food consumed, and by the empty or replete condition of the alimentary tract. On an average a healthy man secretes about fifty ounces of urine in the twenty-four hours. This quantity usually holds in solution about one ounce of urea, and ten or twelve grains of uric acid. In the amount of other animal matters, and saline substances, there is great variation, the quantity of these ranging from a quarter of an ounce to an ounce. The principal saline substances are common salt, the sulphates and phosphates of potassium, sodium, calcium, and magnesium. In addition to the animal and the saline matters, the urine also contains a small quantity of carbonic acid, oxygen and nitrogen.

[pg 87]

## CHAPTER XII.

# PHYSIOLOGICAL ANATOMY.

### THE NERVOUS SYSTEM.

Hitherto, we have only considered the anatomy and functions of the organs employed in Digestion, Absorption, Circulation, Respiration, Secretion and Excretion. We have found the vital process of nutrition to be, in all its essential features, a result of physical and chemical forces; in each instance we have presupposed the existence and activity of the nerves. There is not an inch of bodily tissue into which their delicate filaments do not penetrate, and form a multitude of conductors, over which are sent the impulses of motion and sensation.

Fig. 54. The Nervous System.

Two elements, nerve-fibers and ganglionic corpuscles, enter into the composition of nervous tissue. Ordinary nerve-fibers in the living subject, or when fresh, are cylindrical-shaped filaments of a clear, but somewhat oily appearance. But soon after death the matter contained in the fiber coagulates, and then the fiber is seen to consist of an extremely delicate, structureless, outer membrane, which forms a tube through the center of which runs the axis-cylinder. Interposed between the axis-cylinder and this tube, there is a fluid, containing a considerable quantity of fatty matter, from which is deposited a highly refracting substance which lines the tube. There are two sets of nerve-fibers, those which transmit sensory impulses, called afferent or sensory nerves, and those which transmit motor impulses, called efferent or motor nerves. The fibers when collected in bundles are termed nerve trunks. All the larger nerve-fibers lie side by side in the nerve-trunks, and are bound together by delicate [pg 88][pg 89]connective tissue, enclosed in a sheath of the same material, termed the neurilemma. The nerve-fibers in the trunks of the nerves remain perfectly distinct and disconnected from one another, and seldom, or never, divide throughout their entire length. However, where the nerves enter the nerve-centers, and near their outer terminations, the nerve-fibres often divide into branches, or at least gradually diminish in size, until, finally, the axis-cylinder, and the sheath with its fluid contents, are no longer distinguishable. The investing membrane is continuous from the origin to the termination of the nerve-trunk.

Fig. 55. Division of a nerve, showing a portion of a nervous trunk (a) and separation of its filaments (b, c, d, e.)

In the brain and spinal cord the nerve-fibers often terminate in minute masses of a gray or ash-colored granular substance, termed ganglia, or ganglionic corpuscles.

The ganglia are cellular corpuscles of irregular form, and possess fibrous appendages, which serve to connect them with one another. These ganglia form the cortical covering of the brain, and are also found in the interior of the spinal cord. According to Kölliker, the larger of these nerve-cells measure only 1/200 of an inch in diameter. The brain is chiefly composed of nervous ganglia.

Nerves are classified with reference to their origin, as cerebral—those originating in the brain, and spinal—those originating in the spinal cord.

There are two sets of nerves and nerve-centers, which are intimately connected, but which can be more conveniently studied apart. These are the cerebro-spinal system, consisting of the cerebro-spinal axis, and the cerebral and spinal nerves; and the sympathetic system, consisting of the chain of sympathetic ganglia, the nerves which they give off, and the nervous trunks which connect them with one another and with the cerebro-spinal nerves.

#### THE CEREBRO-SPINAL SYSTEM.

The Cerebro-Spinal Axis consists of the brain and spinal cord. It lies in the cavities of the cranium and [pg 90]the spinal column. These cavities are lined with a very tough fibrous membrane, termed the dura mater, which serves as the periosteum of the bones which enter into the formation of these parts. The surface of the brain and spinal cord is closely invested with an extremely vascular, areolar tissue, called the pia mater. The numerous blood-vessels which supply these organs traverse the pia mater for some distance, and, where they pass into the substance of the brain or spinal cord, the fibrous tissue of this membrane accompanies them to a greater or less depth. The inner surface of the dura mater and the outer surface of the pia mater are covered with an extremely thin, serous membrane, which is termed the arachnoid membrane. Thus, one layer of the arachnoid envelopes the brain and spinal cord, and the other lines the dura mater. As the layers become continuous with each other at different points, the arachnoid, like the pericardium, forms a shut sac, and, like other serous membranes, it secretes a fluid, known as the arachnoid fluid. The space between the internal and the external layers of the arachnoid membrane of the brain is much smaller than that enclosed by the corresponding layers of the arachnoid membrane of the spinal column.

Fig. 56. Cross-section of spinal cord.

The Spinal Cord is a column of soft, grayish-white substance, extending from the top of the spinal canal, where it is continuous with the brain, to about an inch below the small of the back, where it tapers off into a filament. From this nerve are distributed fibers and filaments to the muscles and integument of at least nine-tenths of the body.

The spinal cord is divided in front through the middle nearly as far as its center, by a deep fissure, called the anterior fissure, and behind, in a similar manner, by the posterior fissure. Each of these fissures is lined with the pia mater, which also supports the blood-vessels which supply [pg 91]the spinal cord with blood. Consequently, the substance of the two halves of the cord is only connected by a narrow isthmus, or bridge, perforated by a minute tube, which is termed the central canal of the spinal cord.

Each half of the spinal cord is divided lengthwise into three nearly equal parts, which are termed the anterior, lateral, and posterior columns, by the lines which join together two parallel series of bundles of nervous filaments, which compose the roots of the spinal nerves. The roots of those nerves, which are found along that line nearest the posterior surface of the cord, are termed the posterior roots; those which spring from the other line are known as the anterior roots.

Several of these anterior and posterior roots, situated at about the same height on opposite sides of the spinal cord, converge and combine into what are called the anterior and posterior bundles; then two bundles, anterior and posterior, unite and form the trunk of a spinal nerve.

The nerve trunks make their way out of the spinal canal through apertures between the vertebra, called the inter-vertebral foramina and then divide into numerous branches, their ramifications extending principally to the muscles and the skin. There are thirty-one pairs of spinal nerves, eight of which are termed cervical, twelve dorsal, five lumbar, and six sacral, with reference to that part of the cord from which they originate.

When the cord is divided into transverse sections, it is found that each half is composed of two kinds of matter, a white substance on the outside, and a grayish substance in the interior. The gray matter, as it is termed, lies in the form of an irregular crescent, with one end considerably larger than the other, and having the concave side turned outwards. The ends of the crescent are termed the horns, or cornua, the one pointing forward being called the anterior cornu, the other one the posterior cornu. The convex sides of these cornua approach each other and are united by the bridge, which contains the central canal.

There is a marked difference in the structure of the gray and the white matter. The white matter is composed entirely of nerve fibers, held together by a framework of connective [pg 92]tissue. The gray matter contains a great number of ganglionic corpuscles, or nerve-cells, in addition to the nerve-fibers.

When the nerve-trunks are irritated in any manner, whether by pinching, burning, or the application of electricity, all the muscles which are supplied with branches from this nerve-trunk immediately contract, and pain is experienced, the severity of which depends upon the degree of the irritation; and the pain is attributed to that portion of the body to which the filaments of the nerve-trunk are distributed. Thus, persons who have lost limbs often complain in cold weather of an uneasiness or pain, which they locate in the fingers or toes of the limb which has been amputated, and which is caused by the cold producing an irritation of the nerve-trunk, the filaments, or fibers of which, supplied the fingers or toes of the lost member.

On the other hand, if the anterior bundle of nerve-fibers given off from the spinal cord is irritated in precisely the same way, only half of these effects is produced. All the muscles which are supplied with fibers from that trunk contract, but no pain is experienced. Conversely, if the posterior bundle of nerve-fibers is irritated, none of the muscles to which the filaments of the nerve are distributed contract, but pain is felt throughout the entire region to which these filaments are extended. It is evident, from these facts, that the fibers composing the posterior bundles of nerve-roots only transmit sensory impulses, and the filaments composing the anterior nerve-roots only transmit motor impulses; accordingly, they are termed respectively the sensory and the motor nerve-roots. This is illustrated by the fact that when the posterior root of a spinal nerve is divided, all sensation in the parts to which the filaments of that nerve are distributed is lost, but the power of voluntary movement of the muscles remains. On the other hand, if the anterior roots are severed, the power of voluntary motion of the muscles is lost, but sensation remains.

It appears from these experiments, that, when a nerve is irritated, a change in the arrangement of its molecules takes place, which is transmitted along the nerve-fibers. But, if the nerve-trunks are divided, or compressed tightly at any point [pg 93]between the portion irritated, and the muscle or nerve-centre, the effect ceases immediately, in a manner similar to that in which a message is stopped by the cutting of a telegraph wire. When the nerves distributed to a limb are subjected to a pressure sufficient to destroy the molecular continuity of their filaments, it "goes to sleep," as we term it. The power of transmitting sensory and motor impulses is lost, and only returns gradually, as the molecular continuity is restored.

From what has been said, it is plain that a sensory nerve is one which conveys a sensory impulse from the peripheral or outer part of a nerve to the spinal cord or brain, and which is, therefore, termed afferent; and that a motor nerve is one which transmits an impulse from the nerve centre, or is efferent. So difference in structure, or in chemical or physical composition, can be discerned between the afferent and the efferent nerves. A certain period of time is required for the transmission of all impulses. The speed with which an impulse travels has been found to be comparatively slow, being even less than that of sound, which is 1,120 feet per second.

The experiments heretofore related have been confined solely to the nerves. We may now proceed to the consideration of what takes place when the spinal cord is operated upon in a similar way. If the cord be divided with a knife or other instrument, all parts of the body supplied with nerves given off below the division will become paralyzed and insensible, while all parts of the body supplied with nerves from the spinal cord above the division will retain their sensibility and power of motion. If, however, only the posterior half of the spinal cord is divided, or destroyed, there is loss of sensation alone; and, if the anterior portion is cut in two, and the continuity of the posterior part is left undisturbed, there is loss of voluntary motion of the lower limbs, but sensation remains.

Reflex Action of the Spinal Cord. In relation to the brain, the spinal cord is a great mixed motor and sensory nerve, but, in addition to this, it is also a distinct nervous centre, in which originate and terminate all those involuntary impulses which exert so potent an influence in the preservation and economy of the body. That peculiar power of the cord by which it is enabled to convert sensory into motor impulse [pg 94]is that which distinguishes it, as a central organ, from a nerve, and is called reflex action.

The gray matter, and not the white, is the part of the cord which possesses this power. This reflex action is a special function of the spinal cord, and serves as a monitor to, and regulator of the organs of nutrition and circulation, by placing them, ordinarily, beyond the control of conscious volition.

Fig. 57.

If the foot of a decapitated frog is irritated, there is an instant contraction of the corresponding limb; if the irritation is intense the other limb also contracts. These motions indicate the existence, in some part of the spinal cord, of a distinct nerve-centre, capable of converting and reflecting impulses. It has been found by experiment, that the same movements will take place if the irritation be applied to any portion of the body to which the spinal nerves are distributed, thus giving undoubted evidence that the spinal cord in its entirety is capable of causing these reflections. Fig. 57 represents the course of the nervous impulses. The sensory impulse passes upward along the posterior root, a, until it reaches the imbedded gray matter, b, of the cord, by which it is reflected, as a motor impulse, downward along the anterior root, c, to the muscles whence the sensation was received. This is the reflex action of the spinal cord. There is no consciousness or sensation connected with this action, and the removal of the brain and the sympathetic system does not diminish its activity. Even after death it continues for some time, longer in cold-blooded than in warm-blooded animals, on account of the difference in temperature, thus showing this property of the spinal cord. By disease, or the use of certain poisons, this activity may be greatly augmented, as is frequently observed in the human subject. A sudden contact with a different atmosphere may induce these movements. The contraction of the muscles, or cramp, often experienced by all persons, in stepping into a cold bath, or emerging from the cozy sitting-room into a chilly December temperature, are familiar illustrations of [pg 95]reflex movements. It has been demonstrated that the irritability of the nerves may be impaired or destroyed, while that of the muscles to which they are distributed remains unchanged; and that the motor and sensory classes of filaments may be paralyzed independently of each other.

The reflex actions of the spinal cord have been admirably summed up by Dr. Dalton, as exerting a general, protective influence over the body, presiding over the involuntary action of the limbs and trunk, regulating the action of the sphincters, rectum, and bladder, and, at the same time, exercising an indirect influence upon the nutritive changes in all parts of the body to which the spinal filaments are distributed.

The Brain. The brain is a complex organ, which is divided into the medulla oblongata, the cerebellum, and the cerebrum.

The medulla oblongata is situated just above the spinal cord, and is continuous with it below, and the brain above. It has distinct functions which are employed in the preservation and continuance of life. It has been termed the "vital knot," owing to the fact that the brain may be removed and the cord injured and still the heart and lungs will continue to perform their functions, until the medulla oblongata is destroyed.

The arrangement of the white and gray matter of the medulla oblongata is similar to that of the spinal cord; that is to say, the white matter is external and the gray internal; whereas in the cerebellum and cerebrum this order is reversed. The fibres of the spinal cord, before entering this portion of the brain, decussate, those from the right side crossing to the left, and those from the left crossing to the right side. By some authors this crossing of the sensory and motor filaments has been supposed to take place near the medulla oblongata. Dr. Brown-Sequard shows, however, that it takes place at every part of the spinal cord. The medulla oblongata is traversed by a longitudinal fissure, continuous with that of the spinal cord. Each of the lateral columns thus formed are subdivided into sections, termed respectively the Corpora Pyramidalia, the Corpora Olivaria, the Corpora Restiformia and the Posterior Pyramids.

[pg 96]The Corpora Pyramidalia (see 1, 1, Fig. 58) are two small medullary eminences or cords, situated at the posterior surface of the medulla oblongata; approaching the Pons Varolii these become larger and rounded.

The Corpora Olivaria (3, 3, Fig. 58) are two elliptical prominences, placed exterior to the corpora pyramidalia. By some physiologists these bodies are considered as the nuclei, or vital points, of the medulla oblongata. Being closely connected with the nerves of special sensation, Dr. Solly supposed that they presided over the movements of the larynx.

Fig. 58.

Fig. 59.

The Corpora Restiformia (5, 5, Fig. 59) are lateral and posterior rounded projections of whitish medulla, which pass upward to the cerebellum and form the crura cerebelli, so called because they resemble a leg. The filaments of the pneumogastric nerve originate in the ganglia of these parts.

The Posterior Pyramids are much smaller than the other columns of the medulla oblongata. They are situated (4, 4, Fig. 59) upon the margin of the posterior fissures in contact with each other.

The functions of the medulla oblongata, which begin with the earliest manifestations of life, are of an instinctive [pg 97]character. If the cerebellum and cerebrum of a dove be removed, the bird will make no effort to procure food, but if a crumb of bread be placed in its bill, it is swallowed naturally and without any special effort. So also in respiration the lungs continue to act after the intercostal muscles are paralyzed; if the diaphragm loses its power, suffocation is the result, but there is still a convulsive movement of the lungs for sometime, indicating the continued action of the medulla oblongata.

The Cerebellum, or little brain, is situated in the posterior chamber of the skull, beneath the tentorium, a tent-like process of the dura mater which separates it from the cerebrum. It is convex, with a transverse diameter of between three and one-half and four inches, and is little more than two inches in thickness. It is divided on its upper and lower surfaces into two lateral hemispheres, by the superior and inferior vermiform processes, and behind by deep notches. The cerebellum is composed of gray and white matter, the former being darker than that of the cerebrum. From the beautiful arrangement of tissue, this organ has been termed the arbor vitæ.

The peduncles of the cerebellum, the means by which it communicates with the other portions of the brain, are divided into three pairs, designated as the superior, middle and inferior. The first pass upward and forward until they are blended with the tubercles of the corpora quadrigemina. The second are the crura cerebelli, which unite in two large fasciculi, or pyramids, and are finally lost in the pons varolii. The inferior peduncles are the corpora restiformia, previously described, and consist of both sensory and motor filaments. Some physiologists suppose that the cerebellum is the source of that harmony or associative power which co-ordinates all voluntary movements, and effects that delicate adjustment of cause to effect, displayed in muscular action. This fact may be proved by removing the cerebellum of a bird and observing the results, which are an uncertainty in all its movements, and difficulty in standing, walking, or flying, the bird being unable to direct its course. In the animal kingdom we find an apparent correspondence between the size of the cerebellum and the variety and extent of the movements of the animal. Instances [pg 98]are cited, however, in which no such proportion exists, and so the matter is open to controversy. The general function of the cerebellum, therefore, cannot be explained, but the latest experiments in physiological and anatomical science seem to favor the theory that it is in some way connected with the harmony of the movements. This co-ordination, by which the adjustment of voluntary motion is supposed to be effected, is not in reality a faculty having its seat in the brain substance, but is the harmonious action of many forces through the cerebellum.

The Cerebrum occupies five times the space of all the other portions of the brain together. It is of an ovoid form, and becomes larger as it approaches the posterior region of the skull. A longitudinal fissure covered by the dura mater separates the cerebrum into two hemispheres, which are connected at the base of the fissure, by a broad medullary band, termed the corpus callosum. Each hemisphere is subdivided into three lobes. The anterior gives form to the forehead, the middle rests in the cavity at the base of the skull, and the posterior lobe is supported by the tentorium, by which it is separated from the cerebellum beneath. One of the most prominent characteristics of the cerebrum is its many and varied convolutions These do not correspond in all brains, nor even on the opposite sides of the same brain, yet there are certain features of similarity in all; accordingly, anatomists enumerate four orders of convolutions. The first order begins at the substantia perforata and passes upward and around the corpus callosum toward the posterior margin of that body, thence descends to the base of the brain, and terminates near its origin. The second order originates from the first, and subdivides into two convolutions, one of which composes the exterior margin and superior part of the corresponding hemisphere, while the other forms the circumference of the fissure of Sylvius. The third order, from six to eight in number, is found in the interior portion of the brain, and inosculates between the first and second orders. The fourth is found on the outer surface of the hemisphere, in the space between the sub-orders of the second clasp. A peculiar fact relating to these convolutions is observed by all anatomists: mental [pg 99]development is always accompanied by an increasing dissimilarity between their proportional size.

The cerebral hemispheres may be injured or lacerated without any pain to the patient. The effect seems to be one of stupefaction without sensation or volition. A well-developed brain is a very good indication of intelligence and mental activity. That the cerebrum is the seat of the reasoning powers, and all the higher intellectual functions, is proved by three facts. (1.) If this portion of the brain is removed, it is followed by the loss of intelligence. (2.) If the human cerebrum is injured, there is an impairment of the intellectual powers. (3.) In the animal kingdom, as a rule, intelligence corresponds to the size of the cerebrum. This general law of development is modified by differences in the cerebral texture. Men possessing comparatively small brains may have a vast range of thought and acute reasoning powers. Anatomists have found these peculiarities to depend upon the quantity of gray matter which enters into the composition of the brain.

In the cerebro-spinal system there are three different kinds of reflex actions. (1.) Those of the spinal cord and medulla oblongata are performed without any consciousness or sensation on the part of the subject. (2.) The second class embraces those of the tuber annulare, where the perception gives rise to motion without the interference of the intellectual faculties. These are denominated purely instinctive reflex actions, and include all those operations of animals which seem to display intelligent forethought; thus, the beaver builds his habitation over the water, but not a single apartment is different from the beaver homestead of a thousand years ago; there is no improvement, no retrogression. Trains of thought have been termed a third class of reflex actions. It is evident that the power of reasoning is, in a degree, possessed by some of the lower-animals: for instance, a tribe of monkeys on a foraging expedition will station guards at different parts of the field, to warn the plunderers of the approach of danger. A cry from the sentinel, and general confusion is followed by retreat. Reason only attains its highest development in man, in whom it passes the bounds of ordinary existence, and, with the magic wand of love, reaches outward into the [pg 100]vast unknown, lifting him above corporeal being, into an atmosphere of spiritual and divine Truth.

Fig. 60. Section of the brain and an ideal view of the pneumogastric nerve on one side, with its branches, a. Vertical section of the cerebrum. b. Section of the cerebellum, c. Corpus callosum. d. Lower section of medulla oblongata. Above d, origin of the pneumogastric nerve. 1. Pharyngeal branch. 2. Superior laryngeal. 5. Branches to the lungs. 4. Branches to the liver. 6. Branches to the stomach.

The Cranial Nerves. From the brain, nerves are given off in pairs, which succeed one another from in front backwards to the number of twelve. The first pair, the olfactory nerves, are the nerves of the sense of smell. The second pair are the optic, or the nerves of the sense of sight. The third pair are called the motores oculi, the movers of the eye, from the fact that they are distributed to all the muscles of the eye with the exception of two. The fourth pair and the sixth pair each supply one of the muscles of the eye, on each side, the fourth extending to the superior oblique muscle, and the sixth to the external rectus muscle. The nerves of the fifth pair are very large; they are each composed of two bundles of filaments, one motor and the other sensory, and have, besides, an additional resemblance to a spinal nerve by having a ganglion on each of their sensory roots, and, from the fact that they have three chief divisions, are often called the trigeminal, or trifacial, nerves. They are nerves of special sense, of sensation, and of motion. They are the sensitive nerves which supply the cranium and face, the motor nerves of the muscles of mastication, the buccinator and the masseter, and their third branches, often called the gustatory, are distributed to the front portion of the tongue, and are two of the [pg 101]nerves of the special sense of taste. The seventh pair, called also the facial nerves, are the motor nerves of the muscles of the face, and are also distributed to a few other muscles; the eighth pair, termed the auditory nerves, are the nerves of the special sense of hearing. As the seventh and eighth pairs of nerves emerge from the cavity of the skull together, they are frequently classed by anatomists as one, divided into the facial, or portio dura, as it is sometimes called, and the auditory, or portio mollis. The ninth pair, called the glosso-pharyngeal, are mixed nerves, supplying motor filaments to the pharyngeal muscles and filaments of the special sense of taste to the back portion of the tongue. The tenth pair, called the pneumogastric, or par vagum, are very important nerves, and are distributed to the larynx, the lungs, the heart, the stomach, and the liver, as shown in Fig. 60. This pair and the next are the only cerebral nerves which are distributed to parts of the body distant from the head. The eleventh pair, also called spinal accessory, arise from the sides of the spinal marrow, between the anterior and posterior roots of the dorsal nerves, and run up to the medulla oblongata, and leave the cranium by the same aperture as the pneumogastric and glosso-pharyngeal nerves. They supply certain muscles of the neck, and are purely motor. As the glosso-pharyngeal, pneumogastric, and spinal accessory nerves leave the cranium together, they are by some anatomists counted as the eighth pair. The twelfth pair, known as the hypoglossal, are distributed to the tongue, and are the motor nerves of that organ.

#### THE GREAT SYMPATHETIC.

A double chain of nervous ganglia extends from the superior to the inferior parts of the body, at the sides and in front of the spinal column, and is termed, collectively, the system of the great sympathetic. These ganglia are intimately connected by nervous filaments, and communicate with the cerebro-spinal system by means of the motor and sensory filaments which penetrate the sympathetic. The nerves of this system are distributed to those organs over which conscious volition has no direct control.

[pg 102]

Fig. 61. Course and distribution of the great Sympathetic Nerve

[pg 103]Four of the sympathetic centers, situated in the front and lower portions of the head, are designated as the ophthalmic, spheno-palatine, submaxillary and otic ganglia. The first of these, as its name indicates, is distributed to the eye, penetrates the sclerotic membrane (the white, opaque portion of the eyeball, with its transparent covering), and influences the contraction and dilation of the iris. The second division is situated in the angle formed by the sphenoid and maxillary bone, or just below the ear. It sends motor and sensory filaments to the palate, and velum palati. Its filaments penetrate the carotid plexus, are joined by others from the motor roots of the facial nerve and the sensory fibres of the superior maxillary. The third division is located on the submaxillary gland. Its filaments are distributed to the sides of the tongue, the sublingual, and submaxillary glands. The otic ganglion is placed below the base of the skull, and also connects with the carotid plexus. Its filaments of distribution supply the internal muscles of the malleus, the largest bones of the tympanum, the membranous linings of the tympanum and the eustachian tube. Three ganglia, usually designated as the superior, middle, and inferior, connect with the cervical and spinal nerves. Their interlacing filaments are distributed to the muscular walls of the larynx, pharynx, trachea, and esophagus, and also penetrate the thyroid gland. The use of this gland is not accurately known. It is composed of a soft, brown tissue, and consists of lobules contained in lobes of larger size. It forms a spongy covering for the greater portion of the larynx, and the first section of the trachea. That it is an important organ, is evident from the fact that it receives four large arteries, and filaments from two pairs of nerves.

The sympathetic ganglia of the chest correspond in number with the terminations of the ribs, over which they are situated. Each ganglion receives two filaments from the intercostal nerve, situated above it, thus forming a double connection. The thoracic ganglia supply with motor fibres that portion of the aorta which is above the diaphragm, the esophagus, and the lungs.

In the abdomen the sympathetic centers are situated upon the coeliac artery, and are termed, collectively, the semilunar [pg 104]coeliac ganglion. Numerous inosculating branches radiate from this center and are called, from the method of their distribution, the solar plexus. From this, also, originate other plexi which are distributed to the stomach, liver, kidneys, intestines, spleen, pancreas, supra-renal glands, and to the organs of generation. Four other pairs of abdominal ganglia connected with, the lumbar branches are united by filaments to form the semilunar ganglion.

The sympathetic ganglia of the pelvis consist of five pairs, which are situated upon the surface of the sacrum. At the extremity of the spinal column this system terminates in a single knot, designated as the ganglion impar.

Owing to the position of the sympathetic ganglia, deeply imbedded in the tissues of the chest and abdomen, it is exceedingly difficult to subject them to any satisfactory experiments. A few isolated facts form the basis of all our knowledge concerning their functions. They give off both motor and sensory filaments. The contraction of the iris is one of the most familiar examples of the action of the sympathetic system.

In the reflex actions of the nerves of special sense, the sensation is transmitted through the cerebro-spinal system, and the motor impulse is sent to the deep-seated muscles by the sympathetic system. Physiologists enumerate three kinds of reflex actions, which are either purely sympathetic, or partially influenced by the cerebro-spinal system. Dr. Dalton describes them as follows:

First.—"Reflex actions taking place from the internal organs, through the sympathetic and cerebro-spinal systems, to the voluntary muscles and sensitive surfaces.—The convulsions of young children are often owing to the irritation of undigested food in the intestinal canal. Attacks of indigestion are also known to produce temporary amaurosis [blindness], double vision, strabismus, and even hemiplegia. Nausea, and a diminished or capricious appetite, are often prominent symptoms of early pregnancy, induced by the peculiar condition of the uterine mucous membrane."

Second.—"Reflex actions taking place from the sensitive surfaces, through the cerebro-spinal and sympathetic systems [pg 105]to the involuntary muscles and secreting organs.—Imprudent exposure of the integument to cold and wet, will often bring on a diarrhea. Mental and moral impressions, conveyed through the special senses, will affect the motions of the heart, and disturb the processes of digestion and secretion. Terror, or an absorbing interest of any kind, will produce a dilatation of the pupil, and communicate in this way a peculiarly wild and unusual expression to the eye. Disagreeable sights or odors, or even unpleasant occurrences, are capable of hastening or arresting the menstrual discharge, or of inducing premature delivery."

Third.—"Reflex actions taking place through the sympathetic system from one part of the body to another.—The contact of food with the mucous membrane of the small intestine excites a peristaltic movement in the muscular coat. The mutual action of the digestive, urinary, and internal generative organs upon each other takes place entirely through the medium of the sympathetic ganglia and their nerves. The variation of the capillary circulation in different abdominal viscera, corresponding with the state of activity or repose of their associated organs, are to be referred to a similar nervous influence. These phenomena are not accompanied by any consciousness on the part of the individual, nor by any apparent intervention of the cerebro-spinal system."

[pg 106]

## CHAPTER XIII.

# THE SPECIAL SENSES.

### SIGHT.

The eye is the organ through which we perceive, by the agency of light, all the varied dimensions relations, positions, and visible qualities of external objects.

The number, position, and perfection of the eyes, vary remarkably in different orders, in many instances corresponding to the mode of life, habitation, and food of the animal. A skillful anatomist may ascertain by the peculiar formation of the eye, without reference to the general physical structure, in what element the animal lives. Sight is one of the most perfect of the senses, and reveals to man the beauties of creation. The æsthetic sentiment is acknowledged to be the most refining element of civilized life. Painting, sculpture, architecture, and all the scenes of nature, from a tiny way-side flower to a Niagara, are subjects in which the poet's eye sees rare beauties to mirror forth in the rhythm of immortal verse.

In the vertebrates, the organs of vision are supplied with filaments from the second pair of cranial nerves. In mammalia, the eyes are limited to two in number, which in man are placed in circular cavities of the skull, beneath the anterior lobes of the cerebrum. Three membranes form the lining of this inner sphere of the eye, called respectively the Sclerotic, Choroid, and Retina.

The Sclerotic, or outer covering, is the white, firm membrane, which forms the larger visible portion of the eyeball. It is covered in front by a colorless, transparent segment, termed the cornea, which gives the eye its lustrous appearance. Within the sclerotic, and lining it throughout, is a thin, dark membrane [pg 107]termed the Choroid. Behind the cornea it forms a curtain, called the iris, which gives to the eye its color. The muscles of the iris contract or relax according to the amount of light received, thus enlarging or diminishing the size of the circular opening called the pupil. The Retina is formed by the optic nerve, which penetrates the sclerotic and choroid and spreads out into a delicate, grayish, semi-transparent membrane. The retina is one of the most essential organs of vision, and consists of two layers. A spheroidal, transparent body, termed the crystalline lens, is situated directly behind the pupil. It varies in density, increasing from without inward, and forms a perfect refractor of the light received. The space in front of the crystalline lens is separated by the iris into two compartments called respectively the anterior and posterior chambers. The fluid contained within them, termed the aqueous humor, is secreted by the cornea, iris, and ciliary processes. The space behind the crystalline lens is occupied by a fluid, called the vitreous humor. This humor is denser than the other fluids and has the consistency of jelly, being perfectly transparent. "The function of the crystalline lens is to produce distinct perception of form and outline."[3] The transparent humors of the eye also contribute to the same effect, but only act as auxiliaries to the lens.

Fig. 62.

The figure on the next page represents the course of the rays of light proceeding from an object a b, refracted by the lens, and forming the inverted image x y on the screen. All rays of light proceeding from b are concentrated at y, and those proceeding from a converge at x. Rays of light emanating from the center of the object a b pursue a parallel course, [pg 108]and form the center of the image. Rays of light passing through a double convex lens converge at a point called the focus. In the organ of vision, if perfect, the focus is on the retina, which serves as a screen to receive the image or impression. We have a distinct perception of the outline of a distant hill, and also of a book lying before us. The rays of light we receive from these objects cannot have the same focus. How, then, can we account for the evident accommodation of the eye to the varying distances? Various theories have been advanced to explain this adjustment; such as changes in the curvature of the cornea and lens; a movement of the lens, or a general change in the form of the eyeball, by which the axis may be lengthened or shortened.

Fig. 63.

Two facts comprise all the positive knowledge which we possess on this subject. Every person is conscious of a muscular effort in directing the eye to a near object, as a book, and of fatigue, if the attention is prolonged. If, now, the eyes be directed to a distant object, there will result a sense of rest, or passiveness. By various experiments it has been proved that the accommodation or adjustment of the eye for near objects requires a muscular effort, but for distant objects the muscles are in an essentially passive condition. An increase in the convexity of the crystalline lens is now admitted to be necessary for a distinct perception of near objects. We may give two simple illustrations, cited by Dr. Dalton in his recent edition of Human Physiology. If a candle be held near the front of an eye which is directed to a distant object, three reflected images of the flame will be seen in the eye, one on each of the anterior surfaces of the cornea and lens, and a third on the posterior surface of the latter. If the eye is directed to a near object, the reflection on the cornea remains unchanged, while that on the anterior surface of the lens gradually diminishes and approximates in size the reflection on the cornea, thus giving conclusive evidence that, in viewing a near object, the anterior surface of the crystalline lens become more convex, and at [pg 109]the same time approaches the cornea. Five or six inches is the minimum limit of the muscular adjustment of the eye. From that point to all the boundless regions of space, to every star and nebulæ which send their rays to our planet, human vision can reach. It is the sense by which we receive knowledge of the myriads of worlds and suns which circle with unfailing precision through infinite space.

#### HEARING.

Fig. 64. Internal and external ear. 1. External ear. 2. Internal auditory meatus. 3. Tympanum. 4. Labyrinth. 5. Eustachian tube.

Hearing depends upon the sonorous vibrations of the atmosphere. The waves of sound strike the sensitive portions of the ear, and their impressions upon the auditory nerves are termed the sensations of hearing. The ear is divided into three parts, called respectively the External, Middle, and Internal ear.

The external organs of hearing are two in number, and placed on opposite sides of the head. In most of the higher order of vertebrates, they are so situated as to give expression and proportion to the facial organs, and, at the same time, to suit the requirements of actual life.

The External ear is connected with the interior part by a prolongation of its orifice, termed the external auditory meatus. In man, this gristly portion of the auditory apparatus is about one inch in length, lined by a continuation of the integument of the ear, and has numerous hairs on its surface, to prevent the intrusion of foreign substances. Between the external meatus and the cavity of the middle ear is the membrana [pg 110]tympani, which is stretched across the opening like the head of a drum. The tympanum, or ear-drum, communicates with the pharynx by the eustachian tube, which is a narrow passage lined with delicate, ciliated epithelium. On the posterior portion it is connected with the mastoid cells. Three small bones are stretched across the cavity of the tympanum, and called, from their form, the malleus, incus and stapes, or the hammer, anvil, and stirrup. Agassiz mentions a fourth, which he terms the os orbiculare. Each wave of sound falling upon the membrana tympani, throws its molecules into vibrations which are communicated to the chain of bones, which, in turn, transmits them to the membrane of the foramen ovale. The three muscles which regulate the tension of these membranes are termed the tensor tympani, laxator tympani, and stapedium tympani.

The Labyrinth, or Internal ear, is a complicated cavity, consisting of three portions termed the vestibule, cochlea, and semi-circular canals. The vestibule is the central portion and communicates with the other divisions. The labyrinth is filled with a transparent fluid, termed perilymph, in which are suspended, in the vestibules and canals, small membranous sacs, containing a fluid substance, termed endolymph (sometimes called vitrine auditive from its resemblance to the vitreous humor of the eye). The filaments of the auditory nerve penetrate the membranous tissues of these sacs, and also of those suspended at the commencement of the semi-circular canals. These little sacs are supposed to be the seat of hearing, and to determine, in some mysterious way, the quality, intensity and pitch of sounds.

The determination of the direction of sound is a problem of acoustics. Some have contended that the arrangement of the semi-circular canals is in some way connected with this sensation. But this supposition, together with the theory of the transmission of sound through the various portions of the cranial bones, has been exploded.

From the foregoing description, it will be seen that the labyrinth and tympanum are the most essential parts of the organs of hearing. In delicacy and refinement this sense ranks next to sight. The emotions of beauty and [pg 111]sublimity, excited by the warbling of birds and the roll of thunder, are scarcely distinguishable from the intense emotions arising from sight. It is a remarkable fact, that the refinement or cultivation of these senses is always found associated. Those nations which furnish the best artists, or have the highest appreciation of painting and sculpture, produce the most skillful musicians, those who reduce music to a science.

#### SMELL.

Fig. 65. 1. Frontal sinus. 2. Nasal bone. 3. Olfactory ganglion and nerves. 4. Nasal branch of the fifth pair. 5. Spheno-palatine ganglion. 6. Soft palate. 7. Hard palate, a. Cerebrum, b. Anterior lobes, c. Corpus callosum. d. Septum lucidum. f. Fornix. g. Thalami optici. h. Corpora striata.

Next in order of delicacy, and more closely allied with the physical functions, is the sense of smell. Delicate perfumes, or the fragrance of a flower, impart an exhilarating sensation of delight, while numerous odors excite a feeling of disgust. The organ of smell is far less complicated in its structure than the eye or the ear. It consists of two cavities having cartilaginous walls, and lined with a thick mucous coat, termed the pituitary membrane, over which are reflected the olfactory nerves. Particles of matter, too minute to be visible even through the microscope, are detached from the odorous body and come in contact with the nerves of smell, which transmit the impressions or impulses thus received to the brain. Fig. 65 shows the distribution of the olfactory nerves in the nasal passages. The nose is supplied with two kinds of [pg 112]filaments which are termed respectively nerves of special and nerves of general sensation. Compared with the lower animals, especially with those belonging to the carnivorous species, the sense of smell in man is feeble. The sensation of smell is especially connected with the pleasures and necessities of animal life.

#### TASTE.

The sense of taste is directly connected with the preservation and nutrition of the body. A delicious flavor produces a desire to eat a savory substance. Some writers on hygiene have given this sense an instinctive character, by assuming that all articles having an agreeable taste are suitable for diet. The nerves of taste are distributed over the surface of the tongue and palate, and their minute extremities terminate in well developed papillæ. These papillæ are divided into three classes, termed, from their microscopic appearance, filiform, fungiform and circumvallate. The organ of taste is the mucous membrane which covers the back part of the tongue and the palate. The papillæ of the tongue are large and distinct, and covered with separate coats of epithelium. The filiform papillæ are generally long and pointed and are found over the entire surface of the tongue. The fungiform are longer, small at the base and broad at the end. The circumvallate are shaped like an inverted V and are found only near the root of the tongue; the largest of this class of papillæ have other very small papillæ upon their surfaces. It is now pretty satisfactorily established that the circumvallate, or fungiform papillæ are the only ones concerned in the special sense of taste.

The conditions necessary to taste are, that the substance be in solution either by artificial means, or by the action of the saliva; and that it be brought in contact with the sensitive filaments imbedded in the mucous membrane. The nerves of taste are both general and special in their functions. If the general sensibility of the nerves of taste is unduly excited, the function of sensibility is lost for some time. If a peppermint lozenge is taken into the mouth, it strongly excites the general sensibilities of taste, and the power of distinguishing between special flavors is lost for a few moments. A [pg 113]nauseous drug may then be swallowed without experiencing any disagreeable taste.

Paralysis of the facial nerve often produces a marked effect in the sensibility of the tongue. Where this influence lies has not been fully explained; probably it is indirect, being produced by some alteration in the vascularity of the parts or a diminution of the salivary secretions.

#### TOUCH.

By the sense of touch, we mean the general sensibility of the skin. Sensations of heat and cold are familiar illustrations of this faculty. By the sense of touch, we obtain a knowledge of certain qualities of a body, such as form consistency, roughness, or smoothness of surface, etc. The tip of the tongue possesses the most acute sensibility of any portion of the body, and next in order are the tips of the fingers. The hands are the principal organs of tactile sensation. The nerves of general sensibility are distributed to every part of the cutaneous tissue. The contact of a foreign body with the back, will produce a similar tactile sensation, as with the tips of the fingers. The sensation, however, will differ in degree because the back is supplied with a much smaller number of sensitive filaments; in quality it is the same.

[pg 114]

## CHAPTER XIV.

# CEREBRAL PHYSIOLOGY.

By means of the nervous system, an intimate relation is maintained between mind and body, for nervous energy superintends the functions of both. The fibres of nervous matter are universally present in the organization, uniting the physical and spiritual elements of man's being. Even the minutest nerve-rootlets convey impressions to the dome of thought and influence the intellectual faculties. We recognize muscular force, the strength of the body, molecular force, molecules in motion, as heat, light, chemical force, electricity, and nervous force, a certain influence which reacts between the animal functions and the cerebrum, thus connecting the conditions of the body with those of the mind. We cannot speak of the effects of mind or body separately, but we must consider their action and reaction upon each other, for they are always associated. There are many difficulties in understanding this relationship, some of which may be obviated by a study of the development of nervous matter, and its functions in the lower orders of organization.

Within the plant-cells is found a vital, vegetable substance termed bioplasm, or protoplasm; which furnishes the same nutritive power as the tissues of the polyp and jelly fish. Many families of animals have pulpy bodies, and slight instinctive motion and sensibility, and in proportion as the nervous system is developed, both of these powers are unfolded. Plants have a low degree of sensibility, limited motion, respiratory and circulatory organs. Animals possess quicker perceptions and sensibilities, the power of voluntary motion, and, likewise [pg 115]a rudimental nervous system. Some articulates have no bony skeleton, their muscles being attached to the skin which constitutes a soft contracting envelope. One of the simplest forms of animal life in which a nervous system is found, is the five-rayed star-fish. In each ray there are filaments which connect with similar nerve-filaments from other rays, and form a circle around the digestive cavity. It probably has no conscious perception, and its movements do not necessarily indicate sensation or volition. In some worms a rudimentary nervous system is sparingly distributed to the cavities of the thorax and abdomen, and, as in the star-fish, the largest nerve-filament is found around the esophagus, presiding over nutrition.

Fig. 66.

A higher grade of organization requires a more complete arrangement of nervous substance. Stimulus applied to one organ is readily communicated to, and excites activity in another.

Fig. 67. A. Nervous system of a Crab, showing its ganglia. B. The nervous system of a Caterpillar.

The nervous system of some insects consists of two long, white cords, which run longitudinally through the abdomen, and are dilated at intervals into knots, consisting of collections of nerve-cells, called ganglia. They are really nerve-centers, which receive and transmit impulses, originate and impart nervous influence according to the nature of their organic surroundings. The ganglia situated over the esophagus of insects correspond to the medulla oblongata in man, in which originate the spinal [pg 116]accessory, glosso-pharyngeal, and pneumogastric nerves. The latter possess double endowments, and not only participate in the operations of deglutition, digestion, circulation, and respiration, but are also nerves of sensation and instinctive motion. The suspension of respiration produces suffocation. In insects, these ganglia are scarcely any larger than those distributed within the abdomen, with which they connect by means of minute, nervous filaments. Insects are nimble in their movements, and manifest instinct, corresponding to the perfection of their muscular and nervous systems. When we ascend to vertebrates, those animals having a backbone, the amount of the nervous substance is greater, the organic functions are more complex, and the actions begin to display intelligence.

Man possesses not only a complete sympathetic system, the rudiments of which are found in worms and insects, and a complete spinal system, less perfectly displayed in fishes, birds, and quadrupeds, but, superadded to all these is a magnificent cerebrum, and, as we have seen, all parts of the body are connected by the nervous system. The subtle play of sensory and motor impulses, of sentient and spiritual forces, indicates a perfection of nervous endowments nowhere paralleled, and barely approached by inferior animals. This meager reference to brainless animals, whoso knots of ganglia throughout their bodies act automatically as little brains, shows that instinct arises simultaneously with the development of the functions over which it presides. Here begins rudimentary, unreasoning intelligence. It originates within the body as an inward, vital impulse, is manifested in an undeviating manner, and therefore displays no intention or discretion. While Dr. Carpenter likens the human organism "to a keyed instrument, from which any music it is capable of producing can be called forth at the will of the performer," he compares "a bee or any other insect to a barrel organ, which plays with the greatest exactness a certain number of tunes that are set upon it, but can do nothing else." Instinct cannot learn from experience, or improve by practice; but it seems to be the prophetic germ of a higher intelligence. It is nearly as difficult to draw the dividing line between instinct and a low grade of intelligence, as it is to distinguish [pg 117]between the psychical and psychological[4] functions of the brain.

The intimate relation of instinct to intelligence is admirably illustrated in the working honey-bee. With forethought it selects a habitation, constructs comb, collects honey, provides a cell for the ova, covers the chrysalis, for which it deposits special nourishment, and is disposed to defend its possessions. It is a social insect, lives in colonies, chastises trespassers, fights its enemies, and defends its home. It manifests a degree of intelligence, but its sagacity is instinctive. Reason, though not so acute as instinct, becomes, by education, discerning and keenly penetrative, and reveals the very secrets of profound thought. We recall the aptness of Prof. Agassiz's remark: "There is even a certain antagonism between instinct and intelligence, so that instinct loses its force and peculiar characteristics, whenever intelligence becomes developed." Animals having larger reasoning powers manifest less instinct, and some, as the leopard, exercise both in a limited degree. This double endowment with instinct and low reasoning intelligence, is indicated by his lying in ambush awaiting his prey, the hiding-place being selected near the haunt of other animals, where nature offers some allurement to gratify the appetite.

Simple reflex action is an instinctive expression, manifesting an intuitive perception, almost intelligent, as shown by the contraction of the stomach upon the food, simply because it impinges upon the inner coats, and thus excites them to action. A better illustration, because it displays sympathy, is when the skin, disabled by cold, cannot act, and its duties are largely performed by the kidneys. Though reflex action is easily traced in the lower organic processes, some writers have placed it on a level with rational deliberation. Undoubtedly, all animals having perception have also what perception implies—consciousness—and this indicates the possession, in some [pg 118]degree, of reason. Compound reflex action extends into the domain of thought. Simple reflex action, or instinct, answers to the animal faculties, such as acquisitiveness, secretiveness, selfishness, reproductiveness, etc., and accomplishes two important purposes; self-preservation and the reproduction of the specie. With many persons, these appear to be the chief ends of life!

The psychical functions connect, not only with animal propensities, but also with the highest psychological faculties. Instinct is the representative of animal conditions, just as the highest spiritual faculties are indicative of qualities and principles. The consistent mean of conduct is an equilibrium between these ultimate tendencies of our being. The psychological functions render the animal nature subservient to the rule of purity and holiness, and deeply influence it by the essential elements of spiritual existence. The psychical organs sustain an intermediate relation, receiving the impressions of the bodily propensities, and, likewise, of the highest emotions. Obviously, these extreme influences, the one growing out of animal conditions, the other, the result of spiritual relations, pass into the psychical medium and are refracted by it, or made equivalent to one force. The body requires the qualifying influences of mind. The tendencies of the animal faculties are selfish and limiting, those of the emotive, general, universal. The propensities, like gravity, expend their force upon matter; the emotions pour forth torrents of feeling, and produce rhapsodies of sentiment. The propensities naturally restrict their expression to a specific object of sense; the emotions respond to immaterial being. The tendencies of the former are acquisitive, selfish, gratifying; of the latter, bestowing, expanding, diffusing. The one class is restricted to the orbits of time and matter, the other flows on through the limitless cycles of infinity and immortality. The former is satiated in animal gratification, the latter in spiritual beatification. The one culminates in animal enjoyment, the other expands to its ultimate conceptions in the perfections of Divine Love.

In the present life, mind and body are intimately connected by nervous matter. In this dual constitution, the spiritual mental, and animal functions are made inseparable, and modify [pg 119]one another. The ultimate tendencies of each extreme exist, not absolutely for themselves, but for qualifying purposes, to establish a basis for the deeper economy of life. By the employment of reason, animal and spiritual experiences are mutually benefited, and the consciousness rendered accountable. The bodily and mental workings are in many senses one, and help to interpret each other.

Every fact of mind has many aspects. A brain force, which results in thought, is simultaneously a physiological force, if it influences the bodily functions. Likewise, spiritual conceptions take their rise in the same blood that feeds the grosser tissues. This vital fluid is momentarily imparting and receiving elements from all the bodily organs, and these, in turn, must influence the process of thought, and, in a degree, determine its quality. The delicate outline, yea, even the substance of an idea, may depend upon the condition of the animal organs. Thought is subject to the laws of biology, and, therefore, is a symbol of health. Morbid conditions of the system hang out their signs in words and utterances. Words which express fear are as true symptoms of functional difficulty as is excessive palpitation. The organ representing fear sustains a special relation to the functions of the heart both in health and disease. Bright hopes characterize pulmonary complaints as certainly as cough. Exquisite susceptibility of mind indicates equally extreme sensibility of body, and those persons capable of fully expressing the highest emotions are especially susceptible to bodily sensations. Tears are physical emblems of grief, and fellow-feeling calls forth sympathetic tears. Excessive anxiety of mind produces general excitability of body, which soon results in chronic disease. Pleasurable emotions stimulate the processes of nutrition, and are restorative. This concomitance of mental and bodily states is very remarkable. Joy and Love, as well as jealousy and anger, flash in the eye and mould the features to their expression. Grief excites the lachrymal, and rage the salivary glands. Shame reddens the ears, drops the eyelids, and flushes the face; but profligacy destroys these expressions. The blush which suffuses the forehead of the bashful maiden betrays her love, and maternal love, stirred by the appeals of an idolized infant, excites the mammary gland [pg 120]to the secretion of milk. The sigh of melancholia indicates hepatic torpor, thus showing a special relation between the liver and respiratory organs. These conditions of mind and body react upon one another. Even the thought of a luscious peach may cause the mouth to water. The thought of tasting a lemon fills the mouth with secretions, and a story with unsavory associations may completely turn the stomach.

The relationship of mental and physical functions may be illustrated by entirely removing the spleen of an animal, as that of a dog. An invariable result of its extirpation is an unusual increase of the appetite, for at times the animal will eat voraciously any kind of food. The dog will devour, with avidity, the warm entrails of recently killed animals, and thrive in consequence of such an appetite. Another symptom, which usually follows the removal of the spleen, is an unnatural ferocity of disposition. Without any apparent provocation, the animal will attack others of its own, or of a different species. In some instances, these outbursts of irritability and violence are only occasional, but the experiments show quite conclusively that the spleen moderates combativeness, restrains the appetite, and co-operates with the will and judgment in controlling them.

We shall briefly consider the practical question whether the elements of mind can be ideally arranged and presented, so as to more completely reveal their relations to, and disclose their effects upon the bodily functions. Modern philosophers conceive that mind consists of a triad of essentials; Intellect, Emotion, and Volition. Physiologists assign to the cerebrum its functions, and neurological, as well as phrenological writers, have located them as represented in Fig. 68. True, there is no structural division between the parts of the cerebrum to indicate this diversity of function, nor is there any perceptible limit between the sensory and motor filaments of the game nerve. As no one has any reason for denying that separate portions of the brain may manifest distinct functions of the mind, we shall assume it as a conceded proposition. The regions of the cerebrum, thus ideally represented, occupy but little more than half of the arc of a circle, whereas it is evident that the base of the nervous mass is not idle, and is equally entitled to our consideration. In the posterior chamber [pg 121]of the skull is the cerebellum, anterior to, and below which, is the medulla oblongata, connecting with the spinal cord and sympathetic system. These various parts are essential to the harmonious blending of mind and body. To this end, two conditions are necessary. (1.) All the nervous forces must be so related that action and reaction may be fully established. (2.) A complete nervous circuit is requisite for the reciprocal influence of mind and body.

Fig. 68.

Fig. 69.

Nature answers to mind in physical correspondences. The planetary system is fashioned after a circle. Life itself springs from a spherule of forces. The perfection of an idea, or the completeness of a conception may be expressed by a circle. The elements of Science, Astronomy, Geology, and Natural History, are pictorially represented in this manner. How appropriately and logically can a fragment of natural history, this epitome of all nature and science—the mind—be illustrated by a simple circle! Every element must act and react, and be equal and opposite. Thus may the existence of the opposing energies and functions of each faculty be equally represented. The contrast aids us in understanding their ultimate tendencies, and enables us to correctly value and define their nature. Faculties of kindred qualities may be grouped together, and their antagonisms represented in the opposite arc of the circle. Let us employ a circle to represent mind. The conception of the abstract [pg 122]quality of good, requires contrast with one of a converse nature, bad, (see Fig. 69). Opposite faculties may be portrayed in the same manner. The functions of the cerebrum and spinal system may be symbolically represented as those of the highest and lowest organs, thus giving rise to the positive and negative extremes of feeling. The writer conceives of no other way in which the widely contrasted facts of human experience can be so perfectly symbolized. Good (Fig. 69) may represent moral faculties, and bad, their opposites. Undoubtedly, nature is not so arbitrary in her arrangements as we are in shadowing forth our imperfect conceptions, yet is not this a decided improvement in determining cerebral faculties and their relations? We observe how scholars and philosophers confound the noblest and most exalted emotions with the animal propensities instead of distinguishing between them. "The emotions are a department of the feelings, formed by the intervention of intellectual processes. Several of them are so characteristic that they can be known only by individual experiences; as Wonder, Fear, Love, Anger." See Logic: Deductive and Inductive, by Alexander Bain, LL. D., page 508, (1874).

This is not an exceptional, but a common example of classifying Love, the highest and purest of the emotions, with Anger, an animal propensity. Is it not more practical and philosophical to group the emotional faculties together, and upon an opposite arc represent their antagonistic energies, the ultimate tendencies of which are criminal? Both groups are mutually modifying and restraining; the one relates instinctively to the bodily wants, the other to the requirements of mind, and each is essential to a consistent life. Accordingly, we deem it philosophical to consider words as symbols of mental faculties, and to classify together such spiritual unities as joy, hope, faith, and love, the tendencies of which are to quicken and transform the ultimates of carnal life into the rudiments of an immortal one, the beginning of heaven on earth. These restrain those opposites, which lead to crime and death. Love and Hate are as antagonistic as heat and cold, and the usefulness of both depends upon their proper temperament. Fig. 70 represents the antagonism of the Intellectual [pg 123]faculties to the Animal, the Emotional to the Criminal, the Volitive to the Enfeebling. It is not essential to discover in the nerve-substance the precise power from which an impulse originates. We may reasonably interpret the functions of the brain, and yet be unable to disclose the duties of any ganglionic corpuscle composing it. We may foretell what each season of the year will bring forth, when we cannot forecast the history of a blade of grass or a single grain of any kind. We may predict the amount of rain for a month, and be unable to prognosticate correctly, the character of any storm, or give the history of a special drop of water. Although we cannot follow the movements of individuals in a battle, yet we may predict the result of the combat; and thus, we judge of the functions of the brain without the ability to reveal the actions of one of the organic molecules of which it is composed. We aim to give a general, reasonable, and popular description of cerebral functions and their bearing upon health and disease.

Fig. 70.

#### REGIONAL DIVISIONS.

Fig. 71.

The anterior portion of the cerebrum is devoted to intellectual processes, which freely expend the vital energies. The Intellectual faculties are classified as represented in Fig. 71. The lower portion of the brain, bounded exteriorly by the superciliary ridge, corresponds to the Perceptive, the middle region to the Recollective, and the upper to the Reflective faculties. (See also Fig. 65, b.) If we divide the forehead by vertical lines, as shown in Fig. 71, the divisions thus formed represent respectively, the Active, Deliberative, and Contemplative departments of the intellect, all the processes of which are sustained by vital changes, the transformation of organized materials. No mental effort can be made without waste of [pg 124]nervous matter. The gardener's hoe wears by use, and so does every part of the animal organism. Otherwise, nutrition would be unnecessary for the adult. The production of thought wears away the cerebral substance. In ordinary use, the brain requires one-fifth of the blood to support its growth and repair. Great mental efforts are attended by a corresponding expenditure of vital treasures, which are abstracted from the total forces available for the necessities of the system. To repair the losses thus occasioned, materials are appropriated from the blood, which furnishes supplies in proportion to the demands made by the mental activities. The production of thought wears away the gray matter of the cerebrum as surely as the digging of a canal wears away the iron particles of the spade. The brain would soon wear out did not the nutritive functions constantly make good the waste. The intellect, whether engaged in observation, generalization, or profound study consumes the brain and blood, hence intellectual activity implies VITAL EXPENDITURE. Expenditure is an emphatic word because all functions are essential to the production of this nerve-energy, which returns to the system no equivalent. Physical exercise, although attended by structural waste, is advantageous to the circulation of the blood, nutrition, secretion, and, in fact, beneficial to all the organic processes. This is not true of vigorous and prolonged mental labor, which is not attended by any of these incidental advantages. If a child attends a school in which mental development supersedes physical culture, an inordinate ambition sways the youthful mind, and [pg 125]its baneful effects upon the health soon become manifest. Rigorous application of the intellectual faculties consumes the blood, exhausts the vital forces, weakens the organic functions, while pallor covers the face, and the eyes sparkle with a hectic radiance. The family physician pronounces the condition Anæmia (a deficiency of red corpuscles in the blood), and this change in the quality of the blood is owing to the undue appropriation by the brain. Conversely, if the blood be destroyed, or its vitality reduced, in the same proportion will the mental energies be weakened and all the functional powers of the physical system enfeebled. In brief, if the intellect be unduly exercised, the red corpuscles of the sanguine fluid will be gradually destroyed, and the serum allowed to predominate. The blood becomes weak and watery, the subject is nervous, dropsical, consumptive and derangement of the important functions follows almost invariably. Excessive intellectual activity often produces weak state of the system, and the person thus affected becomes languid, spiritless, and an easy prey to disease. This mental cause and its bodily results may be classified in the following order. Mental Cause: EXCESSIVE MENTAL EXERTION, which produces waste of the brain substance and blood.

| { | VITAL EXPENDITURE,
Bodily results: | ANÆMIA,
| A WEAK CONDITION.

This kind of waste is best summed up in the words, VITAL EXPENDITURE. Upon the forehead, as represented in Fig. 72, we will therefore inscribe INTELLECT, ACTIVITY, and VITAL EXPENDITURE. Intellectual employment is usually accompanied by sedentary habits, neglect of healthful exercise, and a deprivation of pure air, to all of which ill health may be attributed. Were the intellectual expenditure arrested, and the forces turned into recuperative channels, many a person would become beautiful with the ruddy glow of health. Without health there is no use for thought; cultivation of the mind is just as natural and essential as the culture of the body, and the trained development of both is needed for mutual improvement.

[pg 126]

#### EMOTIVE FACULTIES.

Fig. 72.

What results follow the natural and the excessive exercise of the EMOTIVE FACULTIES? AS distinct organs of the body have diverse functions, so, in like manner, different parts of the brain perform the separate operations of the mind. It is easier to discriminate between the products of these dissimilar endowments than to determine the location of the faculties. The intellect deals with concrete subjects, and the emotions with abstractions; the intellect is exercised with material things, the emotions dwell upon attributes; the intellect considers the forces of matter, the emotions, the powers of [pg 127]the soul; the former deliberates upon the truths of science, the latter is concerned with duties, obligations, or moral responsibilities; the first is satisfied only with new truths, original ideas, and rational changes, the last rest securely on fundamental principles, moral certainties, and the absolute constancy of perfect love. The intellectual faculties are wakeful, questioning, mistrustful; the emotions are blind, hopeful, confiding; the one reasoning, exacting, demonstrating; the other, believing, inspiring, devout. The intellect sees, the emotions feel; and, though these functions may blend, the one can never supersede the other.

The quality of the emotional faculties is represented by Benevolence, Sympathy, Joy, Hope, Confidence, Gratitude, Love, and Devotion, all of which are the very antitheses of the attributes of animal feeling, described as Melancholy, Fear, Anger, Hate, Malevolence, and Despair. To the emotions we refer the highest qualities of character, while their opposites represent the animal or baser impulses. True, the emotions modify the propensities, as sympathy softens grief. They may subdue and refine the animal feelings, and thus veil them with a delicacy characteristic of their own purity; but the unrestrained influences of grief find vent in loud lamentations, and the bitter disappointments of the selfish faculties are passionate and violent.

The Emotive Faculties—the organs of spiritual perceptions—are impersonal, outflowing, bestowing. The function represented by Benevolence, is willing, giving. Devotion expresses dedication, consecration; Gratitude manifests a warm and friendly feeling toward a benefactor.

> "The depth immense of endless gratitude."—MILTON.

Love flames toward its object, is out-pouring, blessing; indeed, all the emotions are gushing, effusive, impetuous, and profusely flowing; grand, torrent-like, overwhelming; employing ideal, immaterial, spiritual expressions, developing principles and perfections while aspiring to happiness and immortality. Though beginning with humanity, they embody the Divine. They expand to their ultimate conceptions in the sublime attributes: the perfections of the God of Love; associating [pg 128]with mortality a divine destiny commencing on earth, extending through time, pausing not at the portals of death, the gateway to eternity, but flowing onward into the realms of eternal day.

We may consider their counteracting influences, for, without doubt, by checking the selfish tendencies and restraining the animal propensities, they assist in controlling the sensual passions, and thus balance the mind and body. Such an equilibrium we call happiness. If the emotions be acute and vehement, they will absorb all other impressions and revel in their culminating and delightful experiences. They exhaust all the bodily energies, and a functional suspension, termed ecstasy, follows. It is a swooning, or fainting, a temporary loss of sensation and volition, accompanied by involuntary movements of the arms, smiting of the hands, sighing, and short ejaculatory expressions of rapture. This condition, occasioned by excessive emotion, as in praying, singing, exhortations, and sympathetic appeals, is contagious, often spreading with mysterious rapidity. Its culmination, ecstasy, is popularly termed "the power." When gradually induced, it is called trance, and each state is regarded by many as supernatural, caused by the immediate influence of the Holy Spirit. The explanation is this: when the emotive faculties are suddenly and powerfully excited, they quickly expend the organic forces, so that the individual swoons from sheer exhaustion. Undue expenditure of this class of brain functions not only consumes the bodily powers, but exhausts and prevents other mental operations. The sudden collapse of all voluntary functions resembles the fainting produced by blood-letting. We may sum up this rapid expenditure of energy in one expressive word, EXHAUSTION, which results in Ecstasy, or trance, and which, if carried a degree further, terminates in death. Beginning with the natural exercise of the emotions, we may state the order of sequences thus:

Ordinary exercise leads to | CALMNESS.
Proper exercise | HAPPINESS.
Increased exercise | ECSTASY.
Excessive exercise | SYNCOPE.
Prolonged exercise | TRANCE.
Fatal exercise | MORTALITY.
Their tendencies are | EXHAUSTIVE.

[pg 129]

#### VOLITIVE FACULTIES.

What are the physiological and morbid results attending the ordinary and the immoderate exercise of the VOLITIVE FACULTIES?

The generic term will, comprehends those faculties, the action of which is termed volition. The faculties of the will are Determination, Firmness, Decision, Ambition, Authority, and Vigilance, all of which indicate strength and continuity of purpose. Bordering upon the emotions are Patience and Perseverance, while adjoining the animal faculties are Power, Coarseness, and Love of Display. The former exhibit moral, the latter animal heroism. A sense of power urges forward, whether it be higher or lower, just as the sense of greatness makes a man great by inspiring him with confidence to put forth exertion. Nature is truthful in her aspirations. We know that courage, assurance, and conscious power are necessary for the fulfillment of purpose, because intention precedes action. Will-power is an indication of HEALTH, and the constant exercise of these mental faculties exerts a steady, regular, and strengthening influence over the bodily functions. We translate mental energies into physiological industry. These faculties impart tone to the system, sustain the processes of nutrition, circulation, assimilation, secretion and excretion, and their distinguishing characteristics are vigor, tension, and elasticity. They temper each element of character, as well as every vital act. They infuse the organism with a resisting power which renders it proof against the influence of miasma and malaria, and overcomes that passivity and impressionability so favorable to disease. Firmness expresses a physiological cohesiveness which strongly binds together the fibers of the tissues, and renders the organization compact and powerful. He, who can skillfully employ these energies, is already master of half of the diseases incident to mankind, and wields an indispensable adjunct to medicine, in the practice of the healing art. It is the key to success, for it unlocks difficulties and opens wide the door which leads to favorable results.

Surplus energy sustains the circulation, increases capillary action, as if the excess of nerve-power were discharged from [pg 130]the distant extremity of each nerve and pervaded every tissue. The voluntary muscles indicate their participation in this energy, and, indeed, the whole organism is exalted by the influence of the mental faculties. They oppose the tendencies of Feebleness, Relaxation, and Derangement, and modify their proclivities to Disease. The will is the servant of the intellect, emotions, and propensities, and the executive agent of all the faculties. When the volitive faculties are in excess, they may overdo the other functions, prematurely break down the bodily organs, and, by overtaxing the system, subject it to pain and disorder.

##### VOLITIVE FACULTIES.

The natural effect of FIRMNESS is physiological stability. The exercise of the volitive faculties displays both mental and bodily ENERGY.

| { | TEMPERANCE,
Their tendencies are to | SANITY,
| HEALTH.

#### ANIMAL FACULTIES.

Fig. 73. is a representation of the cranial conformation of Alexander VI., exhibiting a full development of the conservative faculties. His character, according to history, brought reproach upon the papal chair.

Fig. 74. represents Zeno, a profound thinker and moral philosopher. The contrast in their cranial developments was no greater than that of their lives.

Under this generic term we will group those cerebral powers which are common to the inferior animals, and closely allied to bodily conditions and necessities. As denoting a group of animal faculties they relate not only to the organic functions and self-preservation, but combat the action of the intellect, [pg 131]oppose the evolution of new ideas, resist investigation, and discredit the value of truth. Adhesiveness, being blindly conservative, clings to old ideas and traditionary opinions. The animal faculties tend to stifle investigation, and put authority above truth and science. Having a fixity of nature, a stationary attachment, they treat all intellectual developments as absurd. When these faculties predominate, thought is obscured, intolerance of disposition is manifested, and mental progress is arrested. Thus they evince their conservative nature, and, since they relate to individual interests, they represent the elements of instinct. Such are the functions of Acquisitiveness, Secretiveness, Selfishness, and Combativeness, as well as the Generative powers. If these faculties predominate, all intellectual advancements are treated as experiments or theoretical novelties, and rejected as evanescent and worthless. If the promptings of these be followed, there will be no innovation, and the orthodoxy of the dark ages will remain the standard for all time. The animal faculties coincide with Lethargy, Sleep, and Nutrition, thus favoring organic restoration. The intellectual faculties are wakeful, active, irrepressible, while the animal powers tend to repose, sleep, and renovation, and thus suspend the activities of thought, sense, and motion. The intellect expends the energy of the sensorial centers, induces fatigue and suffering, whereas the animal faculties overcome the vigils of thought, and produce refreshing slumber. Dr. Young styles sleep "tired nature's sweet restorer." Swedenborg declared that, "in sleep the brain folded itself up, and the soul journeyed through the body, repairing the wastes of the previous day." When sleep is natural, the insane are in a fair way to recovery, the sick become convalescent, ulcers granulate, and lesions are made whole.

The animal faculties are skeptical, stubborn, and dogmatic, readily combining with those of the violent class, the ultimate tendencies of which are criminal. They are likewise conceited, assuming, and clannish. Any person distinguished by them, will cling to old associations, perpetuate the status of existing parties, be a stickler for creed, ceremonies, and stale opinions, and adhere to ancient orthodoxy in medicine and religion. The animal faculties, since they are staid and regular, are naturally [pg 132]antagonistic to genius, sensibility, and originality. Their mental tendencies have been fairly described and their physiological results may be represented as follows:

| { | RESTRAINT,
| SLEEP,
The animal faculties produce | NUTRITION,
| RESTORATION,
| CONSERVATION.

#### BASILAR FACULTIES.

The ultimate tendencies of the faculties, represented by the posterior base of the cerebrum, are violent and criminal. Being contiguous to the junction of the cerebrum and spinal system, they are subject to the influence of animal experiences. A large development of these faculties is indicated by an unusual breadth and depth of the back part of the base of the brain, and a full, thick neck, both of which denote good alimentary and digestive powers. Active nutrition, plethora of the circulation, vigorous secretion, a well developed muscular system, a large heart and lungs, are accessory conditions. We do not associate corpulence or surplus of vitality with a long, slender neck. The character of cerebral manifestations is represented by the baser faculties of mind, such as Combativeness, Destructiveness, Desperation, Turbulence, Hatred, and Revenge. If unrestrained, these culminate in violent and criminal acts; if regulated, they are employed in personal defense. When unduly excited, they lead to dissipation, obscenity, swearing, rowdyism, and licentiousness; when perverted, they are the source of recklessness, quarrels, frauds, falsehoods, robberies, and homicides. They are unlike instinct, inasmuch as they are not self-limiting. The intimate relation which they sustain to the stomach and nutritive functions is strikingly displayed in the habit of alcoholic intoxication. Spirituous drinks deprave the appetite, derange and destroy the stomach, poison the blood, and pervert all the functions of mind and body; and their injurious influence upon the nerves and basilar faculties is equally remarkable. They excite combativeness, selfishness, irritability, and exaggerate the influence of the animal organs. Intemperance results in disputes, fights, brawls, [pg 133]and murders—the legitimate consequences of which are misunderstandings, suits at law, criminal proceedings, imprisonment, and the gallows. It is, therefore, evident that the ultimate tendencies of these faculties are tyrannical, cruel, violent, and atrocious. They are opposed to the noble, moral faculties—Faith, Love, and Devotion—and, whenever temptation inordinately allures, the course of life is likely to be characterized by dishonorable, deceptive, and treacherous conduct.

The pangs of hunger cause soldiers to act more like ravenous beasts, than rational beings. It is animal instinct which impels the soldier to seek first for the gratification of his appetite. Some persons, instigated by carnivorous desires, yearn for raw meat, and will not be satisfied unless their food is flavored with the flesh of animals. Their bodies increase and thrive, even to repletion. Contrast these individuals with pale, lean, anæmic people, who crave innutritious articles of diet, and eat soft stones, slate, chalk, blue clay, and soft coal. Such perversions of the appetite are manifested only when there is either a diminution in the volume of blood, deficient alimentation, defective assimilation, or a general depravity of the nutritive functions. Morbid conditions generate vitiating tendencies and destroy the natural appetite.

While alcoholic stimulants affect the medulla oblongata principally, opium acts chiefly on the cerebrum, and excites reverie, dreamy ideality, optical delusions, and the creative powers of the imagination; some of these hallucinations are said to be grotesquely beautiful and enjoyable. The effects of this agent differ from those of alcoholic intoxication by not deadening the moral sensibilities, or arousing the animal propensities. Opium smokers are dreamy and abstracted, not quarrelsome or violent. Those who use ardent spirits lose their moral delicacy, their intellect becomes dull, the reason cloudy, and the judgment is overruled by appetite. It is conceded that the trophic center is principally in the medulla oblongata; the cerebellum and lower cerebral ganglia, however, favorably influence the nutritive functions, and, when these organs are large and active, a plethoric condition is the natural consequence. Redundancy of blood in the body indicates preponderance of the basilar organs. These faculties [pg 134]being vehement in character, an excess of animal characteristics produces those conditions which result in acute and inflammatory diseases. We may express these conditions of the system as follows:

The Animal Faculties correspond to the lower instinctive manifestations.

| { | ACQUISITIVENESS,
The elements of character are | SELFISHNESS,
| COMBATIVENESS
They tend to | { | TURBULENCE,
| CRIME.
| { | ALIMENTATION,
They relate especially to the | SECRETION,
functions of | NUTRITION,
| REPRODUCTION.
| { | VITALITY,
A large development of them | PLETHORA,
indicates | HYPERÆMIA (congestion).

These naturally give rise to the following diseases: Inflammation, Rheumatism, Gout, Convulsions, etc., which, in these conditions, pursue a violent course.

#### REGION OF FEEBLENESS.

Although the middle lobe of the cerebrum, at the base of the brain, does not denote decided force of character, or energy of constitution, yet it has a certain sphere of normal action which is essential to the harmony of mind and body. If this region is largely developed, the constitution is languid, inefficient, sensitive, and abnormally disposed. But if it be deficient, the volitive energies preponderate, and there is a lack of those susceptibilities of constitution, which prevent excessive waste. The cerebral faculties are Fear, Anxiety, Sensibility, Servility, Relaxation, and Melancholy, and their excessive predominance indicates a weak, vacillating, irresolute character, and the existence of those bodily conditions which produce general excitability and chronic derangement. A full development of this portion of the brain indicates that the person is naturally dependent, inferior, and subservient to stronger characters. Such a one is fearful, fretful, complaining, irritable, dejected, morose, [pg 135]and, sooner or later, becomes a fit subject for chronic disease.[5] The ultimate result of excessive fear, excitability, and irritability, is functional or organic derangement,—the morbid conditions represented by the word Disease. The medulla oblongata and portions of the middle lobe of the brain, the functions of which represent Excitability, Anxiety, Fear, and Irritability (symbols of physical profligacy), are located just between the ears (see Fig. 60). Inferior animals distinguished for breadth between the ears are not only cunning and treacherous, but very excitable and irritable. The head of the Fox is remarkable for its extreme width at the region of Fear. He is proverbially crafty and treacherous, always excitable, and so variable in temper that he can never be trusted. He is a very timid thief, exceedingly suspicious, irregular in habits, and frequently driven by hunger into mischievous depredations.

Fig. 75. Sly Reynard

The organ of alimentiveness, located directly in front of the ear, indicates the functional conditions of the stomach, which, when aroused by excessive hunger, exerts a debasing influence upon this and all of the adjacent organs, and is demoralizing to both body and mind. In obedience to the instinct of hunger, children will slyly plunder gardens and orchards, displaying profligate, if not reckless tendencies in the gratification of the appetite. In this regional division we include the medulla, the posterior and middle portions of which give rise to the pneumogastric nerve. This nerve receives branches from the spinal accessory, facial, hypoglossal, and the anterior trunks of the first and second cervical, and its filaments are distributed to the [pg 136]lungs, stomach, liver, spleen, pancreas, and gall bladder (see Fig. 60, with explanation) Its agency is necessary to maintain the circulation, and the respiration, since, as the medium of communication, it conveys from the brain large supplies of nervous force to sustain these vital functions. It likewise instantly reports the impressions of these physiological processes to the brain, and especially to those parts which, by analogy of functions. It likewise instantly reports the impressions of these physiological processes of the brain, and especially to those parts which, by analogy of functions, are intimately related to the stomach. Hence, we observe that the conditions of the stomach give rise to reflex impulses, which involuntarily excite the animal faculties to the gratification of the appetite. That the stomach has an intimate connection with the rest of the organism is evident from the fact that when it is inflamed the body is completely prostrated.

We have already alluded to the perverting tendencies of alcoholic stimulants. Their peculiar influence upon the cerebellum causes the subject to reel and stagger, as though a portion of that organ were removed; the group of energetic faculties is stupefied, and mental as well as corporeal lethargy is the result. The reaction, which inevitably follows, is almost unbearable, and relief is sought by repeating and increasing the poisonous draughts, the primary influence of which is stimulating, the ulterior, depressing. Alcoholic stimulants unduly excite the nervous centers, the heart, and the arteries, and, consequently, the blood is carried to the surface of the body, where it counteracts the influence of cold and exposure, the frequent attendants upon drunkenness. The use of alcoholic beverages perverts the appetite, interrupts habits of industry and destroys all force of character. Pecuniary, physical, and mental ruin, therefore, are sure to follow as the consequences of habitual, alcoholic intoxication.

That ordinary alimentation, which includes the process of digestion, the subsequent vital changes involved in the conversion of food into blood, and its final transformation into tissue, causes mental languor and dullness, as well as bodily exhaustion, is attested by universal experience. A torpid condition of the liver, one of the most inveterate of chronic derangements, is [pg 137]indicated by sullenness, melancholy, despondency, loss of interest in the affairs of life, sluggishness, etc., and the ultimate tendency of this morbid state is towards suicide. A broad and deep development of the middle lobe of the brain, shown by a fullness under the chin, and of the adjacent portion of the neck, denotes tendencies to somnambulism, delirium, and insanity. If such characteristics of the organization do not culminate in mental derangement, they exhibit childishness, helplessness, and great dependence. Age abates the vigor of the executive faculties, and old people manifest not only bodily infirmities, but the relaxing and enfeebling influences proceeding from the lower portions of the brain. They totter about in their second childhood, mentally and physically enervated. Those who become dissipated by the use of intoxicating beverages are not only weak, trifling, and foolish, but walk with an unsteadiness which betrays their condition. These illustrations show that this part of the brain is destitute of energy. Diseases of the digestive organs also indicate it. Cholera, whether induced by invisible animalcules in the air, or in water, takes the route of the alimentary canal, opens the vital gates, and myriads of victims are swept down to death. It proves remarkably fatal to those having this cerebral conformation. Perhaps enough has been said to indicate the relaxing and enfeebling tendencies of this region of the brain. They may be classified as follows:

REGION OF FEEBLENESS.
| { | SERVILITY,
| CAUTIOUSNESS,
| FEAR,
Cerebral Functions: | ANXIETY,
| SENSIBILITY,
| CUNNING,
| PROFLIGACY.
| { | ATONIC,
Physiological conditions | EXCITABILITY,
and tendencies: | RELAXATION,
| FEEBLENESS,
| DISEASE.

This classification shows their tendencies to chronic disease, functional derangement, insanity, and suicide.

[pg 138]

#### GENERAL CONSIDERATIONS.

Before the structure of the brain was understood, Buffon spoke of it as a "mucous substance of no great importance." Its functional significance was so slightly appreciated that some people hardly suspected they had any brains, until an accident revealed their existence. Latterly, however, it is generally understood that the perfection of an animal depends upon the number and the development of the organs controlled by the nervous system, the sovereign power of which is symbolized by a grand cerebrum, the throne of Reason. That animal which is so low in the scale of organization as to resemble a vegetable, belongs to an ascending series ending in man. The lowest species have no conscious perception, and their movements do not necessarily indicate sensation or volition. Instinct culminates in the Articulates, especially in Insects; while created intelligence reaches its acme in man, the highest representative of the Vertebrates.

> "All things by regular degrees arise—
> From mere existence unto life, from life
> To intellectual power; and each degree
> Has its peculiar necessary stamp,
> Cognizable in forms distinct and lines."—LAVATER.

Fig. 76. Outline of Skulls. 1. European. 2. Negro. 3. Tiger. 4. Hedge Hog. 5. Sloth.

Man, in the faculties of mind, possesses more than a complement for instinct; some of the lower animals, however, seem to share his rational nature, and to a certain degree become responsible to him. Finally, the manifestations of mind bear a relation to the development of cerebral substance, and to the bodily organization which supplies the brain with blood. Fig. 76 shows the relative amount of brain matter in the lower animals, compared with [pg 139]that of man; the peculiarities of each agreeing with its cerebral conformation. It is easier to measure the capacity of skulls in different races than to procure and weigh their brains. The following table has been published.

CRANIAL CAPACITY OF HUMAN RACES.
Race. | CUBIC INCHES.
--- | ---
Swedes, | 100.00
Anglo-Saxons, | 96.60
Finns, | 95.00
Anglo-Americans, | 94.30
Esquimaux, | 86.32
North America Indians, | 84.00
Native Africans, | 83.70
Mexicans, | 81.70
American Negros, | 80.80
Peruvians and Hottentots, | 75.30
Australians, | 75.00
Gorilla, adult, | 34.50
Idiot, | 22.57

Mr. Davis, of England, having a collection of about eighteen hundred cranial specimens obtained from different quarters of the globe, ascertained the relative volume of brain in different races, by filling the skulls with dry sand. He found that the European averaged 92 cubic inches, the Oceanic 89, the Asiatic 88, the African 86, the Australian 81. Dr. Morton, of Philadelphia, had a collection of over one thousand skulls, and his conclusions were that the Caucasian brain is the largest, the Mongolian next in size, the Malay and American Indian smaller, and the Ethiopian smallest of all. The average weight of brain, in 278 Europeans, was 49.50 oz., in 24 White American soldiers, 52.06 oz., indicating a greater average for the American brain.

| OUNCES
--- | ---
The brain of Cuvier, the celebrated naturalist, weighed | 64.33
Ruloff, the murderer and linguist, | 59.00
Dr. Spurzheim—phrenologist, | 55.06
Celebrated philologist, | 47.90
Celebrated mineralogist, | 43.24
Upholsterer, | 40.91

The weight of the human brain varies from 40 to 70 oz.; that of idiots from 12 to 36 40 oz. The average of 273 [pg 140]male European brains was 49½ oz., while that of 191 females was 44 oz. If we compare the weight of the female brain with that of the body, the ratio is found to be as 1:36.46, while that of the male is as 1:36.50; showing that, relatively, the female brain is the larger. It appears that neither the absolute nor relative size of the cerebrum, but the amount of gray matter which it contains, is the criterion of mental power. Although a large cerebrum is generally indicative of more gray matter than a small one, yet it is ascertained that the grey substance depends upon the number, and depth of the convolutions of the brain, and the deeper its fissures, the more abundant is this tissue. It is this substance which is the source of thought, while the white portion only transmits impressions.

We do not wish to underrate any attempt heretofore made to classify the functions of mind and assign to them an appropriate nomenclature. It is not unusual for scientists to give advice to phrenologists and point out the fallacies of their system; but it is hardly worth while to indulge in destructive criticism, unless something better is offered, as the day has passed for ridiculing endeavors to understand and interpret the physiology of the brain. The all important question is, not whether phrenologists have properly located and rightly earned all the faculties of mind, but have their expositions been useful in the development of truth. While endeavoring to connect each mental power with a local habitation in the brain, the system of phrenology may be chargeable with some incongruous classification of the faculties, and yet it has furnished an analysis of the mind which has been of incalculable service to writers upon mental philosophy. Phrenology, in popularizing its views, has interested thousands in their own organizations and powers, who would otherwise have remained indifferent. It has called attention to mental and bodily unities, has served as a guide to explain the physical and psychical characteristics of individuals, and has been instrumental in applying physiological and hygienic principles to the habits of life, thus rendering a service for which the world is greatly indebted. Samuel George Morton, M.D., whose eminent abilities and scholarship are unquestionable, employs the following language:

[pg 141]"The importance of the brain as the seat of the faculties of the mind, is pre-eminent in the animal economy. Hence, the avidity with which its structure and functions have been studied in our time; for, although much remains to be explained, much has certainly been accomplished. We have reason to believe, not only that the brain is the center of the whole series of mental manifestations, but that its several parts are so many organs, each one of which performs its peculiar and distinctive office. But the number, locality, and functions of these several organs are far from being determined; nor should this uncertainty surprise us, when we reflect on the slow and devious process by which mankind has arrived at some of the simplest physiological truths, and the difficulties that environ all inquiries into the nature of the organic functions."

Fig. 77. Side view of the brain of a Cat. A. Crucial sulcus dividing anterior convolutions. B. Fissure of Sylvius. C. Olfactory bulb.

We may here allude to the recent experimental researches with reference to the functions of various portions of the brain, prosecuted by Dr. Ferrier, of England. He applied the electric current to different parts of the cortical substance of the cerebrum in lower animals which had been rendered insensible by chloroform, and by it could call forth muscular actions expressive of ideas and emotions. Thus, in a cat, the application of the electrodes at point 2, Fig. 77, caused elevation of the shoulder and adduction of the limb, exactly as when a cat strikes a ball with its paw; at point 4, corrugation of the left eye-brow, and the drawing inward and downward of the left ear; when applied at point 5, the animal exhibited signs of pain, screamed, and kicked with both hind legs, especially the left, at the same time turned its head around and looked behind in an astonished manner; at point 6, clutching movement of the [pg 142]left paw, with protrusion of the claws; at point 13, twitching backward of the left ear, and rotation of the head to the left and slightly upward, as if the animal were listening; at point 17, restlessness, opening of the mouth, and long-continued cries as if of rage or pain; at a point on the under side of the hemisphere, not shown in this figure, the animal started up, threw back its head, opened its eyes widely, lashed its tail, panted, screamed and spit as if in furious rage; and at point 20, sudden contraction of the muscles of the front of the chest and neck, and of the depressors (muscles) of the lower jaw, with panting movements. The movements of the paws were drawn inward by stimulating the region between points 1, 2, and 6; those of the eyelids and face were excited between 7 and 8; the side movements of the head and ear in the region between points 9 and 14; and the movements of the mouth, tongue and jaws, with certain associated movements of the neck, being localized in the convolutions bordering on the fissure of Sylvius (B), which marks the division between the anterior and middle lobes of the cerebrum. Dr. Ferrier made similar experiments on dogs, rabbits, and monkeys. The series of experiments made on the brain of the monkey is said to be the most remarkable and interesting, not only because of the variety of movements and distinctly expressive character of this animal, but on account of the close conformity which the simple arrangement of the convolutions of its brain bears to their more complex disposition in the human cerebrum. It is premature to say what import we shall attach to these experiments, but they have established the correctness of the doctrine, advanced on page 105, that thought, the product of cerebral functions, is a class of reflex actions. The cerebrum is not only the source of ideas but also of those co-ordinate movements which correspond to and accompany these ideas. Certain cerebral changes call forth mental states and muscular movements which are mutually responsive. They indicate that various functions are automatic, or dependent upon the will, and, as we have seen, experiments indicate that the electric current, when applied to the cerebrum, excites involuntary reflex action. We cannot say how far these experimental results justify the phrenological classification of the faculties of mind, by establishing a causative relation [pg 143]between the physical and psychical states. This short and unsatisfactory account furnishes one fact which seems to support the claim of such a relation: the apparent similarity between the motor center of the lips and tongue in lower animals, and that portion of the human cerebrum in which disease is so often found to be associated with Aphasia, or loss of voice. While these experiments are by no means conclusive in establishing a theory, yet they favor it.

It is wonderful that nervous matter can be so arranged as not only to connect the various organs of the body, but at the same time to be the agent of sensation, thought, and emotion. It is amazing, that a ray of light, after traversing a distance of 91,000,000 miles, can, by falling upon the retina, and acting as a stimulus, not only produce a contraction of the pupil, but excite thoughts which analyze that ray, instantly spanning the infinitude of trackless space! The same penetrative faculties, with equal facility, can quickly and surely discern the morbid symptoms of body and mind, become familiar with the indications of disease, and classify them scientifically among the phenomena of nature. The symptoms of disease which follow certain conditions as regularly as do the signs of development, and mind itself is no exception to this uniformity of nature. Thoughts result from conditions, and manifest them as evidently as the falling of rain illustrates the effect of gravity. The perceptive and highest emotive faculties of man depend upon this simple, but marvelously endowed nervous substance, which blends the higher spiritual with the lower physical functions. The functions of the body are performed by separate organs, distinguished by peculiar characteristics. To elucidate the distinctions between dissimilar, mental faculties, we have assigned their functions, with characteristic names, to different regions of the head. As they unquestionably influence the bodily organs, we are sustained by physical analogy, in our classification. Our knowledge of the structure and functions of the nervous system is yet elementary, and we are patiently waiting for scientists to develop its facts, and verify them by experimental investigations and such researches as time alone can bring to perfection. While real progress moves with slow and measured [pg 144]foot-steps, the inspirations of consciousness and the inferences of logic prepare the popular mind for cerebral analysis. No true system can contradict the facts of our inner experience; it can only furnish a more complete explanation of their relation to the bodily organs. It should be expected that such careful and pains-taking experiments, as are necessary to establish a science, will be preceded by intuitive judgments and accredited observations, which may be, for a time, the substitutes of those more abstruse in detail.

We have, in accordance with popular usage, treated the organs of thought as having anatomical relations. The views which we have presented in this chapter may seem speculative, but the facts suggesting the theory demand attention, and we have attempted to gather a few of the scattered fragments and arrange them in some order, rather than leave them to uncertainty and greater mystery. It is by method and classification that we are enabled to apply our knowledge to practical purposes. Possibly, to some, especially the non-professional, an allusion to the fact that cerebral physiology contributes to successful results in the practice of medicine, may seem to be an exaggerated pretension. None, however, who are conversant with the facts connected with the author's experience, will so regard this practical reference, for the statement might be greatly amplified without exceeding the bounds of truth. Physicians generally undervalue the nervous functions, and overlook the importance of the brain as an indicator of the conditions of the physical system, because they are not sufficiently familiar with its influence over the bodily functions. Pathological conditions are faithfully represented by the thoughts, and words, when used to describe symptoms, become the symbols of feelings which arise from disease. How few physicians there are who can interpret the thoughts, and glean, from the expressions and sentences of a letter, a correct idea of the morbid conditions which the writer wishes to portray! Each malady, as well as every temperament, has its characteristics, and both require careful and critical analysis before subjecting the patient to the influence of remedial agents.

In a treatise by Dr. J.R. Buchanan, entitled "Outlines of Lectures on the Neurological System of Anthropology," are [pg 145]presented original ideas pre-eminently useful to the physician. His researches, and those of later writers, together with our own investigations, have greatly increased our professional knowledge. It is by such studies and investigations that we have been prepared to interpret, with greater facility, the indications of disease, and diagnose accurately from symptoms, which have acquired a deeper significance by the light of cerebral physiology. We are enabled to adapt remedies to constitutions and their varying conditions, with a fidelity and scientific precision which has rendered our success in treatment widely known and generally acknowledged. We annually treat thousands of invalids whom we have never beheld, and relieve them of their ailments. This has been accomplished chiefly through correspondence. When patients have failed to delineate their symptoms currently, or have given an obscure account of their ailments, we have been materially assisted in ascertaining the character of the disease by photographs of the subjects. The cerebral conformation indicates the predisposition of the patient, and enables us to estimate the strength of his recuperative energies. Thus we have a valuable guide in the selection of remedies particularly suited to different constitutions. In the treatment of chronic diseases, the success attending our efforts has been widely appreciated, not only in this, but in other countries where civilization, refinement, luxurious habits, and effeminating customs, prevail. This fact is mentioned, not only as an illustration of the personal benefits actually derived from a thorough knowledge of the nervous system, but to show how generally and extensively these advantages have been shared by others.

A careful study of cerebral physiology leads us deeper into the mysteries of the human constitution, and to the philosophical contemplation of the relations of mind and body. Self-culture implies not only a knowledge of the powers of the mind, but also how to direct and use them for its own improvement, and he who has the key to self-knowledge, can unlock the mysteries of human nature and be eminently serviceable to the worlds For centuries the mind has been spreading out its treasury of revelations, to be turned to practical account, in ascertaining the constitution, and determining better methods of treating [pg 146]disease. Since comparative anatomists and physiologists have revealed the structure of animals and the functions of their organs, from the lowest protozoan to the highest vertebrate, the physician may avail himself of this knowledge, and thus gain a deeper insight into the structure and physiology of man. An intimate acquaintance with the physical, is a necessary preparation for the study of the psychical life, for it leads to the understanding of their mutual relations and reactions, both in health and disease.

Consciousness, or the knowledge of sensations and mental operations, has been variously defined. It is employed as a collective term to express all the psychical states, and is the power by which the soul knows its own existence. It is the immediate knowledge of any object whatever, and seems to comprise, in its broadest signification, both matter and mind, for all objects are inseparable from the cognizance of them. Hence, the significance of the terms, subjective-consciousness and objective-consciousness. People are better satisfied with their knowledge of matter than with their conceptions of the nature of mind.

#### THE NATURE OF MIND.

Since this subject is being discussed by our most distinguished scientists, we will conclude this chapter with an extract from a lecture delivered by Prof. Burt G. Wilder, at the American Institute:

"There now remains to be disposed of, in some way, the question as to the nature and reality of mind, which was rather evaded at the commencement of the lecture. The reason was, that I am forced to differ widely from the two great physiologists whom I have so often quoted this evening. Most people, following in part early instruction, in part revelation, in part spiritual manifestations, and in part trusting to their own consciousness, hold that the human mind is a spiritual substance which is associated with the body during the life of the latter in this world, and which remains in existence after the death of the body, and forms the spiritual clothing or embodiment of the immortal soul; and that the individual, therefore, lives after death as a spirit in the human form; that of this spiritual man, [pg 147]the soul is the essential being, of which may be predicted a good or evil nature, while the mind, which clothes it as a body, consists of the spiritual substances, affections, and thoughts, which were cherished and formed during the natural life.

Together with the above convictions respecting themselves, most people, when thinking independently of theological sublimations, feel willing to admit that animals have, in common with man, fewer or more natural affections and thoughts which make up their minds, but that the inner and immortal soul, which would retain them as part of an individual after death of the body, is not possessed by the beasts that perish. In short, the vast majority of mankind, when thinking quietly, and especially in seasons of bereavement, feel well assured of the real and substantial existence of the human mind, independently of its temporary association with the perishable body.

But in antagonism to this simple and comforting faith, stand theological incomprehensibilities on the one hand, and scientific skepticism on the other. The former would have us believe that the soul is a mere vapor, a cloud of something ethereal, of which can be expected nothing more useful than 'loafing around the Throne,' while the latter asks us to recognize the existence of nothing which the eyes cannot see and fingers touch; to cease imagining that there is a soul, and to regard the mind as merely the product of the brain; secreted thereby as the liver secretes bile. Let us hear what the two leading nervous physiologists, of this country, have to say upon this point:

'The brain is not, strictly speaking, the organ of the mind, for this statement would imply that the mind exists as a force, independent of the brain; but the mind is produced by the brain substance; and intellectual force, if we may term the intellect a force, can be produced only by the transmutation of a certain amount of matter; there can be no intelligence without brain substance.'—FLINT.

'The mind may be regarded as a force, the result of nervous action, and characterized by the ability to perceive sensations, to be conscious, to understand, to experience emotions, and to will in accordance therewith. Of these qualities, consciousness resides exclusively in the brain, but the others, as is clearly shown by observation and experiment, cannot be restricted to [pg 148]that organ, but are developed with more or less intensity, in other parts of the nervous system.'—HAMMOND.

Thus do the two extremes of theology and science meet upon a common ground of dreamy emptiness, and we who confess our comparative ignorance are comforted by the thought that some other things have been 'hid from the wise and prudent and revealed unto babes.' Yet, while feeling thus, it must be admitted that the existence of spirit and of a Creator do not yet seem capable of logical demonstration. The denial of their existence is not incompatible with a profound acquaintance with material forms and their operations; and, on the other hand, the belief in their existence and substantial nature, and in their powers as first causes, have never interfered with the recognition of the so-called material forces, and of the organisms through which they are manifested. At present, at least, these are purely matters of faith; but although the Spiritualist (using the term in its broadest sense as indicating a belief in spirits), may feel that his faith discloses a beauty and perfection in the union, otherwise imperceptible by him, there is no reason why this difference in faith should make him despise or quarrel with his materialist co-worker, for the latter may do as good service to science, may be as true a man, and live as holy a life, although from other motives.

The differences between religious sects are mainly of faith, not of works, and the wise of all denominations are gradually coming to the conviction that they will all do God more service by toleration and co-operation than by animosity and disunion. And so I hold that, until the spiritualist feels himself able to demonstrate to the unbeliever the existence of spirit and of God, as convincingly as a mathematical proposition, there should be no hard words or feelings upon these points. For the present they are immaterial in every sense of the word; and so long as he bows to the facts and the laws of Nature, and deals with his fellow men as he would be done by, so long will I work with him, side by side, knowing, even though I cannot tell him so, that whether or not he joins me in this world, we shall meet in the other world to come, where his eyes will be opened, and where his lips will at least acquit me of bigotry and intolerance."

[pg 149]

## CHAPTER XV.

# THE HUMAN TEMPERAMENTS.

Organization implies vital energy, since there can be no organization without it. The sperm cell, as we have previously seen, exists before the initiation of the life of every individual organism. The early history of this fertilizing cell, which is composed of infinitesimal molecules which contain the embryo powers of life, is only partially written. It is a fact, authenticated by Faraday, that one drop of water contains, and may be made to evolve, as much electricity as, under a different mode of display, would suffice to produce a lightning-flash. Chemical force is of a higher order than physical, and vital force is of a still higher order. Within the microscopic compass of the sperm cell are a great number of forces acting simultaneously, which require the answering conditions of a germ cell, and are so blended as to occupy a minimum of space. The union of these subtle elements through the agency of their physical, chemical, and vital forces, constitutes the initiation of life. Elementary matter is transformed into chemical and organic compounds, by natural forces, upon the cessation of which, it is liberated by nature's great destroyer, and re-appears in the world of elements. Thus, man is formed out of the very dust by means of energies which reconstruct the crude, inert matter, and to dust he returns when those energies cease.

When we enter upon the consideration of the temperaments, we should bear in mind one peculiarity of life: that it combines, in a small space, many complex powers. In the process of reproduction, there is a complex combination of organic elements. Structures differ as greatly as their functions. So [pg 150]likewise do animals vary in their nature and organization, and individuals of the same species are, in some respects, dissimilar. Yet the characteristics which have distinguished the races of mankind, are fundamental and faithfully maintained. Time does not obliterate them. Within race-limits are found enduring peculiarities, and, although each individual is weaving out some definite pattern of organization, it follows the type of the race, as well as the more immediate, antecedent condition.

What then is a Temperament but a mixing together of these determining forces, a certain blending manifested in the constitution by signs, or traits, which we denominate character. The different races of mankind must have their several standards of temperament, for the peculiarities of one are not fully descriptive of, and applicable to the other.

The term temperament is defined by Dunglison, as being "a name given to the remarkable differences that exist between individuals, in consequence of the variety of relations and proportions between the constituent parts of the body.

For its simplicity and scope, we prefer the following definition, suggested by our friend, Orin Davis, M.D.: A TEMPERAMENT IS A COMBINATION OF ORGANIC ELEMENTS SO ARRANGED AS TO CHARACTERIZE THE CONSTITUTION.

This leads us to consider some of the elements, conditions and forces which give character to the organization. External circumstances supply necessary conditions to inward activity, for without air, food, or sunlight all living animals would perish. Everywhere, life is dependent upon conditions and circumstances; it is not self-generating. But the conditions of reproduction are very complex. External forces are transformed, and, in turn, become vital or formative powers. Development is a transmutation of physical and chemical forces into vital energy. Although unable to compute the ultimate factors of life, yet we may illustrate their reproductive possibilities and results by comparing them with those of a lower order.

Animal structures are mainly composed of four elements: oxygen, hydrogen, nitrogen and carbon. Other constituents, such as phosphorus, sulphur, potassium, sodium, calcium, magnesium, and iron, enter into their composition, but are [pg 151]found in much smaller quantities. From these elements is fabricated an organism which manifests peculiar properties and marvelous functions. If the proportion of these chemical elements be varied, the organic compound will be changed, or, the proportions remaining the same, if the grouping of the elements be altered, different compounds will be produced, showing that the properties of organized substances depend upon the molecular constitution of matter.

Rising in the scale of organization, we observe that every variation of the physical and chemical processes implies a corresponding modification of the vital. This is verified by the peculiarities of the several races of mankind. Individual differences are likewise modifications of these processes. Dynamical or vital differentiation depends upon these modifications for the display of vital energy, and is always associated with molecular changes. But it should be borne in mind that an effect may not resemble its cause in properties, and the qualities of a chemical compound may be quite different from those of its individual constituents. Organic matter, although more complex, may exhibit properties, both like and unlike its constituent elements. Within certain boundaries, the elements seek to satisfy their affinities. We discover that there are limits between the genera of animals, as well as the races of mankind. Not less really, though perhaps not as absolutely, are there individual precincts within the sphere of the human temperaments, which cannot be passed.

If we cannot satisfactorily explain, we can at least discover a reason for temperamental limitation. It is not designed to circumscribe healthful reproduction, but to serve as an effectual hindrance to abnormal deviations. We may state our belief in more positive terms: that the temperamental variations are essential to genesis and fertility, and indispensable to health and normal development.

Every individual is susceptible to impressions which dispose to action. Impressions which excite or increase this disposition, are called stimuli. Vital change implies the existence of stimuli and susceptibility to stimulation. The stimulus may not be furnished because the conditions on which it depends are wanting; again, susceptibility may exist at one time and not [pg 152]at another. Stimuli and susceptibility may be present in different degrees, but for the purpose of healthful reproduction they must not be impaired. No single class of foods, albuminous, starchy, saccharine, or mineral, is sufficient for the nutrition of the body, but the food must contain substances belonging to each of the different classes. If an animal be fed exclusively upon albumen, though this substance constitutes the largest part of the bodily mass, exhaustion will rapidly follow, since the food does not contain all the essential, nutritive elements. Again, when the solids of the body have been wasted, they lose their susceptibility to stimuli, and the food does no good. Thus patients become emaciated during acute attacks of disease, upon the cessation of which they are too feeble to recover, simply because they have lost the power to digest and assimilate their food.

In inanimate bodies, as in crystals, forces come to rest, but the very idea of life implies action and continual change. Hence diversity of constitutions and different temperaments are essential in order that marriage may result in the reproduction of vigorous beings.

#### VITAL AND NON-VITAL TEMPERAMENTS.

Fig. 78.

In the preceding chapter, we attempted to illustrate the unique blending of mind and body by means of the nervous system, and we now propose to exemplify the physical conditions of the organism by certain correspondences, observed in the development and conditions of that system. If nature answer to mind in physical correspondences, she will observe the same regularity in physical development. The simplest classification of the temperaments is represented in Fig. 78. Not only is mental activity dependent upon a vital activity in the brain, but the development of the cerebrum is dependent upon the supply of blood. The growth of the intellect requires the same conditions that aided in the [pg 153]development of Vulcan's right arm: waste and supply; disintegration and reparation of tissue. Our modern iron forges produce many an artisan whose great right arm proclaims him to be a son of power as well as of fire. Thus the fervid intellect, while forging out its thoughts, increases in size and strength. The difference between the development of the two is this; that the exercise of the blacksmith's right arm quickens the activities of all the bodily functions, whereas the employment of the intellect does not offer any healthy equivalent. Physical exercise is a hygienic demand, but intellectual employment exerts no salutary influence on the body, while it is constantly expending the nutritive energies of the blood. The emotions, likewise, make exhaustive draughts upon nutrition to supply the waste of brain substance, just as certainly as physical labor causes muscular change, and demands reparation. One expends cerebral, the other, muscular substance. The one is healthful in its general tendencies, the other, comparatively wasteful and destructive.

| { | DISINTEGRATING,
The intellectual faculties are | EXPENDING,
| DERIVING.
| { | ENGROSSING,
The emotive faculties are | EXHAUSTING,
| DEVITALIZING.

These nervous forces are transformed into spiritual products.

The base of the anterior lobes of the brain belong to the atonic region—the source of those languid, deranging influences which coincide with morbidity and disease. A disturbance of the corporeal organs, which especially influence this portion of the brain, naturally tends to the development of insanity or imbecility. Morel has traced, through four generations, the family history of a youth who was admitted to the asylum at Rouen while in a state of stupidity and semi-idiocy. The following summary of his investigations illustrates the natural course of degeneracy as it extends through successive generations: immorality, depravity, alcoholic excess, and moral degradation, in the great-grandfather, who was killed in a tavern brawl; hereditary drunkenness, maniacal attacks, ending in general paralysis, in the grandfather; [pg 154]sobriety, but hypochondriacal tendencies, delusions of persecutions, and homicidal tendencies in the father; defective intelligence in the son. His first attack of mania occurred at sixteen, and was followed by stupidity, and finally ended in complete idiocy. Furthermore, there was probably an extinction of the family, for the son's reproductive organs were as little developed as those of a child of twelve years of age. He had two sisters who were both defective physically and morally, and were classed as imbeciles. To complete the proof of heredity in this case, Morel adds that the mother had a child while the father was confined in the asylum, and that this child exhibited no signs of degeneracy. Statistics show that multitudes of human beings are born with a destiny against which they have neither the will nor the power to contend; they groan under the worst of all tyrannies, the tyranny of a bad organization, which is theirs by inheritance. We may represent the tendencies of the anterior portion of the brain by Fig. 79. The functional exercise of the anterior and superior portions of the cerebrum is disintegrating and devitalizing, while the anterior and inferior portions coincide with mental and physical derangement, unless counteracted by opposing forces. It is therefore evident that in any organization, upon which is entailed a perverted or excessive action of this portion of the cerebrum, the tendencies are NON-VITAL, i.e., unfavorable to fertility and physical health.

If the antagonizing regions are well developed, the tendencies are favorable to life.

| { | SANITY,
The volitive organs promote | TEMPERANCE,
| HARDIHOOD.
| { | NUTRITION,
The animal organs tend to | RESTORATION,
| CONSERVATION.
| { | SECRETION,
The basilar faculties instigate | CIRCULATION,
| VITALITY.
| { | ENERGY,
The combined action of these | HEALTH,
faculties express | REPRODUCTION.

Fig. 79

If this portion of the brain indicates a full development, we [pg 155]say of such a temperament that it is VITAL, because the functions of its nerve-centers are favorable to evolution. As degeneration observes conditions, so endurance and development conform to certain laws, and it is the duty of all truthful inquirers, who believe not only in the progress of human intelligence, but in physical improvement from generation to generation, to ascertain and comply with these essential conditions. When the anterior and middle lobes of the brain are fully developed at their inferior surfaces, it is regarded as an insane temperament, i.e. containing the germs of mental and bodily derangement.

[pg 156]How shall we distinguish the combination of organic elements, if not by the manner in which they characterize the constitution? Every human being is distinguished by natural peculiarities, both mental and physical. These are indicated not only by the color of the eyes, hair, and skin, and the mental expressions, but in the conformation and capabilities of the corporeal system. The color, form, size, and texture of a leaf indicate to the expert pomologist the nature of the fruit which the tree will bear, but how much more important is it to understand the harmonies of human development. If Prof. Agassiz could determine the form and size of a fish by seeing its scales, and Prof. Owen outline the skeleton of an unknown animal by viewing a portion of its fossil, why should not the physician understand the language of temperaments, since it opens to him the revelations of human development? The sculptor blends character with form, the artist endows the face with natural expression, the anatomist accurately traces the nerves and arteries, the physiognomist reads character, which the novelist delineates and the actor personates, because there are facts behind all these, the materials wherewith to construct a science. In organization there are permanent forces which operate uniformly, thus revealing the order of nature.

#### THE TEMPERAMENTS CLASSIFIED.

Fig. 80

We propose to speak of four constitutional variations entitled to separate consideration; the lymphatic, the sanguine, the volitive, and the encephalic. The brain controls all the voluntary, and modifies the involuntary functions of the body. A particular cerebral development modifies the functions of all the bodily organs, and thus tempers the constitution. We shall, therefore, base our classification of temperaments upon the mental and physiological characteristics, which are portrayed by cerebral development. Such an arrangement is illustrated by Fig. 80.

[pg 157]

#### THE LYMPHATIC TEMPERAMENT.

The lymphatic temperament predominates when the anterior base of the brain and the middle lobe are developed so as to exert a preponderating influence over the bodily functions. The character of this influence we have described in cerebral physiology. It is difficult to state precisely the normal influences and nerve-forces which arise from these faculties, but it is evident that they are specially related to nutritive attraction, in opposition to volitive repulsion. It is only their excessive influence which produces worthless, miserable, morbid characters. A constitution marked by this development is indolent, relaxative, and an easy prey to epidemics. This treatment is also characterized by a low grade of vitality or resistance. When life is sustained by the volitive powers, it is distinguished by a softness of the bodily tissues, and the prevalence of lymph. The fact that all the organic functions are performed indolently, indicates lack of vital power. An excellent illustration of this temperament is found in Fig. 81, which represents a Chinese gentleman of distinction. In the lower order of animals, as in sponges, absorption is performed by contiguous cells, which are quite as effortless as in plants. Because of their organic indolence, sponges are often classed as vegetables. A body having an atonic or a lymphatic temperament is abundantly supplied with absorbent organs, which are very sluggish in their operations. In the lymphatic temperament, there seems to be less constructive energy, slower elaboration, and greater frugality. Lymph is a colorless or yellow fluid containing a large proportion of water. It is not so highly organized as the blood, but resembles it, when that fluid is deprived of its red corpuscles. In the sanguine temperament, circulation in the blood-vessels is the most active, in the lacteals next, and in the lymphatics the least so, but in the lymphatic temperament, this order is reversed.

Fig. 81.

Dr. W.B. Powell has observed that a lymphatic man has a large head, while a fat man has a small one, and also that fat and lymph, are convertible, one following the other, i.e., "a repletion consisting of fat may be removed, and one of lymph may replace it, and vice versa." He could not account [pg 158]for these alternations. The bear goes into his winter quarters sleek and fat, and comes forth in the spring just as plump with lymph, but he loses this fat appearance soon after obtaining food. This simply indicates that, during lymphatic activity, the digestive organs are comparatively quiescent. But when these are functionally employed again, lymphatic economy is not required. It is the duty of the lymphatics to slowly convert the fat by such transformation, that when it reaches the general circulation, it may there unite with other organic compounds, the process being aided by atmospheric nitrogen, introduced during the act of respiration. In this way it may become changed into those chemically indefinite, artificial products, called proteid compounds. This view is supported by the disappearance of fat as an organized product in the lymph of the lymphatic vessels, indicating that such transformation has occurred. In this way, by uniting with other organic compounds, [pg 159]it appears that lymph may serve as a weak basis for blood; that atmospheric nitrogen is also employed in forming these artificial compounds, is indicated by the fact that there is sometimes less detected in arterial than in venous blood.

Fig. 82. Judge Green, of the United States Court.

This temperament is indicated by lymphatic repletion, soft flesh, pale complexion, watery blood, slow and soft pulse, oval head, and broad skull, showing breadth at its base. Fig. 82 illustrates this temperament combined with sanguine elements. In all good illustrations of this temperament, there is a breadth of the anterior base of the skull extending forward to the cheek bones. There is likewise a corresponding fullness of the face under the chin, and in the neck, denoting a large development of the anterior base of the cerebrum. The cerebral conformation of the Hon. Judge Green indicates mental activity, and we have no reason to suppose that lymph was particularly abundant in his brain.

Fig. 83.

While this description of the lymphatic temperament is correct, when illustrated by the civilized races of men who are [pg 160]accustomed to luxury, ease, and an abundance of food, it does not apply with equal accuracy to the cerebral organization of the American Indian. His skull, though broad at its anterior base, and high and wide at the cheek bones, differs from the European in being broader and longer behind the ears. Fig. 83 is an excellent representation of a noted North American Indian. While a great breadth of the base of the brain indicates morbid susceptibilities, yet these, in the Indian, are opposed by a superior height of the posterior part of the skull. Consequently, he is restless, impulsive, excitable, passionate, a wanderer upon the earth. The basilar faculties, however, are large, and he is noted for instinctive intelligence. His habits alternate from laziness to heroic effort, from idleness and quiet to the fierce excitement of the chase, from vagabondism to war, sometimes indolent and at other times turbulent, but under all circumstances, irregular and unreliable. In this case, lacteal activity is greater than lymphatic, as his nomadic life indicates. Nevertheless, he manifests a morbid sensibility to epidemic diseases, especially those which engender nutritive disorders and corrupt the blood. Figs. 84 and 85 represent the brain of an American Indian, and that of a European, and show the remarkable difference in their anatomical configuration. Evidently it is a race-distinction. Observe the greater breadth of the brain of the Indian, which according to cerebral physiology indicates great alimentiveness, indolence, morbid sensibility, irritability, profligacy, but also note that it differs materially in the proportion of all its parts, from the European brain. Judging the character of the Indian from the aforesaid representation, we should say that he was cunning, excitable, treacherous, fitful, taciturn, or violently demonstrative. His constitution is very susceptible to diseases of the bowels and blood. His appetite is ungovernable, and his [pg 161]love of stimulants is strong. Syphilitic poison, small-pox, and strong drink will annihilate all these tribes sooner than gunpowder. Their physical traits of constitution are no less contradictory than their extremes of habit and character, for while there is evidence of lymphatic elements, yet it is contradicted by the color of the hair, eyes, and skin. This peculiar organization will not blend in healthful harmony with that of the European, and this demonstrates that the race-temperaments require separate and careful analytical consideration.

Fig. 84. American Indian.

Fig 85. European. (FROM MORTON'S CRANIA AMERICANA.) In the American Indian, the anterior lobe, lying between AA, and BB, is small, and in the European it is large, in proportion to the middle, lying between BB and CC. In the American Indian, the posterior lobe, lying between C and D Is much smaller than in the European. In the Indian, the cerebral convolutions on the anterior lobe and upper surface of the brain, are smaller than the European. If the anterior lobe manifests the intellectual faculties—the middle lobe the propensities common to man with the lower animals—and the posterior lobe, the conservative energies, the result seems to be, that the intellect of the American Indian is comparatively feeble—the European, strong; the animal propensities of the Indian will be great—in the European, more moderate; while reproduction, vital energy, and conservation of the species in the Indian is not as great as with the European. The relative proportions of the different parts of the brain differ very materially.

By physical culture and regulation of the habits, the excessive tendencies of this temperament may be restrained. Solid food should be substituted for a watery diet. If it be limited [pg 162]in quantity, this change will not only diminish the size, but increase the strength of the body. The body should be disciplined by daily percussion until the imperfectly constructed cells, which are too feeble to resist this treatment, are broken and replaced by those more hardy and enduring. Add to this treatment brisk, dry rubbing, calisthenic exercises, and daily walks, which should be gradually extended. Continue this treatment for three months, and its favorable effects upon the temperament will surprise the most skeptical; if continued for a year, a radical alteration will be effected, and the hardihood, health, and vigor of the constitution will be greatly increased.

This temperament may be improved physiologically, by being blended with the sanguine and volitive. The offspring will be stronger, the structures firmer, the organization more dense. Nutrition, assimilation, and all the constructive functions will be more energetic in weaving together the cellular fabric of the body. The sanguine temperament will add a stimulus to the organic activities, while the volitive will communicate manly, brave, and enduring qualities. When this temperament is united with the encephalic, if such a union does not result in barrenness, it adds expending and exhaustive tendencies to the enfeebling'ones already existing, and, consequently, the offspring lacks both physical power and intellectual activity.

The peculiarities of this temperament are observed in the diseases which characterize it. It is specially liable to derangements of digestion, nutrition, and blood-making. The blood is easily poisoned by morbid products formed within the body, as well as by those derived from the body of another. This is seen in pyæmia, produced by the introduction of decomposing pus, or "matter," into the blood. This condition is most likely to occur when the vital powers are low and the energies weak, for then the fibrin decreases, the red corpuscles diminish in number, the circulation becomes languid, the pulse grows fluttering and weak, and this increases until death ensues. An individual of this temperament is more easily destroyed than any other by the poison of syphilis, small-pox, and other contagious diseases. If the blood has received any hereditary taint, the lymphatic glands not only reproduce it but often increase the virulency of the original disease. This temperament indicates [pg 163]a necessity for the employment of stimulating, alterative, and antiseptic medicines. The torpid functions need arousing, the blood needs depuration, i.e., the elimination of corrupting matter, and the system requires alteratives to produce these salutary changes. The secretions need the correcting influence of cleansing remedies for the purification of the blood.

Persons of this temperament are more liable to absorption of morbid products within the body, which are in a state of decomposition, producing an infection of the blood, technically termed septicæmia. The fatal results which so suddenly follow child-bed fever are thus produced. This kind of poisoning sometimes takes place from the absorption of decomposed exudation in diphtheria, and, though rarely, from decomposing organic products collected in the lungs. Whenever the absorption of poison does take place, fatal consequences usually follow.

This passive temperament is more likely to sink under acute attacks of disease, especially alimentary disorders, such as diarrhea, dysentery, and cholera. It quickly succumbs to their prostrating effects, such as depression, congestion, and fatal collapse which rapidly succeed one another. Venesection and harsh purgatives are contra-indicated, and the physician who persists in their employment kills his patient. How grateful are warmth and stimulating medicines! The most powerful, diffusible, and nervous stimulants are required in cholera, when the system is devastated by the disease, as the plain is laid waste by the fierce tornado.

#### THE SANGUINE TEMPERAMENT.

Lymph is the characteristic of the lymphatic temperament, and its specific gravity, temperature, and standard of vitality are all lower than that of red blood. In the sanguine temperament all the vital functions are more active, the blood itself has a deeper hue, its corpuscles carry more oxygen, the complexion is quite florid, and the arterial currents impart to every faculty a more hopeful vigor. The blood-vessels are the most active absorbents, eagerly appropriating nutritive materials for the general circulation, while the respiration adds to it oxygen, that agent which makes vital manifestation possible. This temperament exhibits greater sensibility, the [pg 164]conceptions are quicker, the imagination more vivid, the appetite stronger, the passions more violent, and there is found every display of animal life and enjoyment.

A full development of the basilar faculties, indicated by an unusual breadth and depth of the base of the brain, accompanies this temperament. Its cerebral area includes the posterior and inferior portions of the cerebrum, the entire cerebellum, and that part of the medulla which connects with the spinal cord, all of which sustain intimate relations to vital conditions. Accordingly, such a development indicates good digestion, active nutrition, vigorous secretion, large heart and lungs, powerful muscles, and surplus vitality. The violent faculties, such as Combativeness, Destructiveness, and Hatred, are natural adjuncts, and their excess tends to sensuality and crime. They are not only secretive, appropriative, selfish, and self-defensive, but when redundant are aggressive and tend to destructiveness, the gratification of animal indulgence, intemperance, and debauchery. The correspondence between the cerebral conformation and the physical development is very obvious. Lower orders of animals possess these faculties, and their spontaneous exhibition is called instinct. They possess the acquisitive, destructive, and propagative propensities, which lead them to provide for their wants and secure to themselves a posterity. The exercise of their bodies causes a continual waste which demands incessant reparation, and they are governed measurably by these animal impulses.

All of these lower psychical faculties have a physiological significance. Acquisitiveness functionally expresses assimilation, accretion, animal growth, and tends to bodily repletion. Secretiveness expresses concealing, separating, withdrawing, and functionally signifies secretive action. Secretion is the separating and withdrawing from the blood some of its constituents, as mucus, bile, saliva, etc. This latter process indicates complex conditions of organization, so that the higher and more complex the tissue, the greater the number of secretory organs. Unrestrained selfishness, while it naturally conserves the individual interests, in its ultimate tendencies, is the very essence of human depravity. Without qualification, clearly, it is crime, for blind devotion to the individual must be in [pg 165]utter disregard for the good of others. The ultimate tendencies of these faculties are, therefore, criminal.

Exaggerate the faculty of acquisitiveness, and it becomes avariciousness. Develop secretiveness and selfishness, and they become cunning and profligacy, desperation and crime. Their functional development tends to produce physical disorder and violent disease. All of these faculties are vehement, contentious, thriving by opposition. Life itself has been called a forced state, because it wars with the elements it appropriates, and transmutes their powers into vitality.

Fig. 86.

We find men and women of this temperament, who are models of character and organization. George Washington is an excellent illustration. The impression that his presence made upon the Marquis de Chastellux, is given in the following words: "I wish only to express the impression General Washington has left on my mind; the idea of a perfect whole, brave without temerity, laborious without ambition, generous without prodigality, noble without pride, virtuous without severity." Gen. Scott, Lord Cornwallis, Dr. Wistar, Bishop Soule John Bright, Jenny Lind Goldsmidt, and Dr. Gall are good representatives of this temperament. Fig. 86 is an excellent illustration of it, finely blended and well balanced, in the person of Madame de Stael. This temperament requires fewer tonics and stimulants than the lymphatic. This constitution is best able to restore vital losses. It is a vital temperament, in other words, it combines favorably with all the others, and better adapts itself to their various conditions. Some regard it as the best adjusted one in all its organs and tissues, and as the most satisfactory and serviceable.

[pg 166]

Fig. 87.

Excess of nutrition tends to plethora, to animal indulgence, and gross sensuality. Not only do the propensities rouse desire, but they excite the basilar faculties, and portray their wants in the outlines of the face, mould the features to their expression, and flash their significance from the eye. Who can mistake the picture of sensuality represented by Fig. 87? It is enough to shock the sensibility of a dumb animal, and to say that such a face has a beastly look, is an unkind reflection upon the brute creation. A large neck and corresponding development of the occipital half of the brain indicate nervous energy, yet nutrition is not absolutely dependent upon it, for the nutritive processes are active before a nervous system is formed. The lower faculties of the mind exert a remarkable influence over nutrition, secretion, and the molecular changes incident to life. Anger or fear may transmute the mother's nourishing milk into a virulent poison. The following incident, taken from Dr. Carpenter's Physiology, illustrates this statement: "A carpenter fell into a quarrel with a soldier billeted in his house, and was set-upon by the latter with his drawn sword. The wife of the carpenter at first trembled from fear and terror, and then suddenly threw herself between the combatants, wrested the sword from the soldier's hand, broke it in pieces, and threw it away. During the tumult, some neighbors came-in and separated the men. While in this state of strong excitement, the mother took up her child from the cradle, where it lay playing, and in the most perfect health, never having had a moment's illness; she gave it the breast, and in so doing sealed its fate. In a few minutes the infant left-off sucking, became restless, [pg 167]panted, and sank dead upon the mother's bosom. The physician who was instantly called-in, found the child lying in the cradle, as if asleep, and with its features undisturbed; but all resources were fruitless. It was irrecoverably gone. In this interesting case, the milk must have undergone a change, which gave it a powerful sedative action upon the susceptible nervous system of the infant."

Anxiety, irritation, hatred, all tend to the vitiation of the disposition and bodily functions, perverting the character and constitution at the same time. Depravity of thought and secretion go together. Degradation of mind and corruption of the body are concomitants. There is a very close affinity between mental and moral perversion and physical prostitution, of which fact too many are unconscious. Nervous influence preserves the fluidity of the blood and facilitates its circulation, for it appears that simple arrestment of this influence favors the coagulation of the blood in the vessels; clots being found in their trunks within a few minutes after the brain and spinal marrow are broken down. Habitual constipation is the source of many ills. Perversion of the functions of the stomach, and of the circulation of the blood, produce general disaster.

Diseases which characterize this temperament are acute, violent, or inflammatory, indicating repletion and active congestion; intense inflammation, burning fevers, severe rheumatism, a quick, full pulse, great bodily heat, and functional excitement are its morbid accompaniments. These diseases will bear thorough depletion of the alimentary canal, active, hydragogue cathartics being indicated. Sedatives and anodynes are also essential to modify the circulatory forces, and to relieve pain. Violent disturbance must be quelled, and among the remedial agents required for this duty we may include Veratrum, Ipecac, Digitalis, Opium, Conium, and Asclepias. While equalizing the circulatory fluids, restoring the secretions, and thoroughly evacuating the system, and thus endeavoring to remove disturbing causes, we find that the conditions of this temperament are exceedingly favorable for restoration to health. True, many chronic diseases are obstinate, yet a course of restorative medication persistently followed, promises a fortunate issue in this tractile temperament.

[pg 168]Hygienic management of the lymphatic and sanguine temperaments consists in the vigorous toning of the former, while restraint of the latter will greatly exempt it from the anxieties, contentions, and vexations which excite the mind, disturb the bodily functions, and end in chronic disease. People of the latter organization love mental and physical stimulants, are easily inflamed by passion, and their excitability degenerates into irritability, succeeded by serious functional derangements, which prematurely break down the individual with inveterate, deep-seated disorder. Serenity, hope, faith, as well as firmness, are natural hygienic elements. It is a duty we owe ourselves to promptly relinquish a business which corrodes with its cares, and depresses with its increasing troubles. Constant solicitude, and the apprehension of financial disaster, frustrate the bodily functions, disconcert the organic processes, and lead to mental aberration as well as physical degeneracy. Melancholy is chronic, while despair is acute mania, whose impulses drive the victim desperately toward self-destruction. The chronic derangement of these organs exerts with less force the same morbid tendency. Hence the necessity for exercising those hygienic and countervailing influences born of resolution, assurance, and confident trust, and the belief which strengthens all of the vital operations.

Doubtless, this temperament is the source of the reproductive powers. It is the corner-stone essential to the foundation of all other temperaments. It has been supposed by some that the cerebellum is the seat of sexual instinct. The fact appears that an ample development of the posterior base of the cerebrum and the cerebellum indicates nutritive activity, which is certainly a condition most favorable to the display of amativeness. In a double sense, then, this temperament is a vital one; both by nutritive repletion, and by reproduction. It is the blood-manufacturing, tissue-generating, and body-constructing temperament, causing growth to exceed waste, and promptly repairing the wear which follows continual labor.

While the sleazy structures of the lymphatic temperament are favorable to the functions of transudation, exhalation, and mutual diffusion of liquids, the sanguine, as its name indicates, is adapted to promote the circulation of the blood, to favor [pg 169]nutrition and reproduction. The former temperament does not move the world by its energies, or impress it vividly with its wisdom, and the latter is more enthusiastic, enjoyable, and quickening. Each temperament, however, possesses salient qualities and advantages.

#### THE LIFE LINE.

Dr. W.B. Powell, in his work on "The Human Temperaments," announces the discovery of a measurement which indicates the tenacity of life, and the vital possessions of the individual. He has observed that some persons of very feeble appearance possess remarkable powers of resistance to disease, and continue to live until the machinery of life literally wears out. Others, apparently stronger and more robust, die before the usual term of life is half completed. He also noticed that some families were remarkable for their longevity, while others reached only a certain age, less than the average term of life, and then died. He remarked also that some patients sank under attacks of disease, when, to all appearances, they should recover, and that others recovered, when, according to all reasonable calculations, they ought to die. He, therefore, not only believed that the duration of human life was more definitely fixed by the organization than is supposed, but he set himself to work to discover the line of life, and the measure of its duration. He made a distinction between vital vigor, and vital tenacity. Vital vigor he believed to be equivalent to the condition of vitality, which is indicated by the breadth of the brain found in the sanguine temperament; and vital tenacity to be measured by the depth of the base of the brain. Dr. Powell was an indefatigable student of nature, and followed his theory through years of observation, and measured hundreds of heads of living persons, in order to verify the correctness of the hypothesis. His method of measuring the head may be stated as follows: He drew a line from the occipital protuberance on the back of the head to the junction of the frontal and malar bones, extending it to a point above the center of the external orbit of the eye, near the termination of the brow. Then he measured the distance between this line and the orifice of the [pg 170]ear and thus obtained the measure indicating the vital tenacity or duration of, life. Fig. 88 is a representation of the skull of Loper, who was executed for murder in Mississippi. He might have attained a great age, had not his violent and selfish faculties led him into the commission of crime. In this illustration, B represents the occipital protuberance, and A the junction of the frontal and malar bones at the external angle of the eye. The distance between this line (A B) and the external orifice of the ear, is the measure of the life-force of Loper at the time of his: execution.

Fig. 88.

Fig. 89.

The tenacity of an individual's life, Dr. Powell determined by the following scale of measurements: three-fourths of an inch from the orifice of the ear to the life-line, is the average length in the adult, and indicates ordinary tenacity of life. As the distance decreases to five-eighths, one-half, or three-eighths of an inch, vital tenacity diminishes. If the distance is more than three-quarters of an inch, it denotes great vital endurance, excellent recuperative powers, and is indicative of longevity. If it measures less than half an inch, it shows that the constitution has a feeble, uncertain hold upon life, and an acute disease is very likely to sunder the vital relations. Dr. Powell contended that "life force and vital force are not equivalent terms, because much more vital force is expended upon our relations, than upon our organization in the preservation of life. Every muscular contraction, every thought, [pg 171]and every emotion requires an expenditure of vital force." He asserted that we inherit our life force or constitutional power, and that we can determine by this life-line, the amount which we so receive. And he believed that it could be increased by intellectual effort, just as we can increase vital force by physical exercise. Fig. 89 represents the skull of a man who died, at nearly the same age as Loper, of consumption, in the Charity Hospital, at New Orleans. The measurement of the skull in this case gives a space between the life-line and the orifice of the ear of one-sixteenth of an inch, showing that the consumptive had lived the full term of his life. Dr. Powell contended that the depth of a man's brain may be increased after maturity; muscular effort, mental activity, and a sense of responsibility being favorable to longevity, while idleness and dissipation are adverse to it. In justice to the Doctor, we have stated fully his theory and his method of determining the hardihood and endurance of the constitution, and we bespeak for it a candid examination. Without doubt it embodies a great deal of truth. Hereafter we shall endeavor to indicate by cerebral configuration, a better system of judging of the vital tenacity, hardihood, and constitutional energies, both inherited and acquired.

#### THE VOLITIVE TEMPERAMENT.

By reference to Figs. 72 and 80, the reader will be able to locate the region of the volitive faculties, previously described under the generic term will. This temperament is characterized by ambition, energy, industry, perseverance, decision, vigilance, self-control, arrogance, love of power, firmness, and hardihood. These faculties express concentration of purpose and their functional equivalents are power of elaboration, constructiveness, condensation, firmness of fiber, compactness of frame, and endurance of organization. The pulse is full, firm, and regular, the muscles are strong and well marked, the hair and skin dark, the temporal region is not broadly developed, the face is angular, its lines denoting both power of purpose and strength of constitution, with resolution and hardihood blended in the expression. The volitive temperament is distinguished by height of the posterior, superior occipital region, called the [pg 172]crown of the back head, and by corresponding breadth from side to side. The rule given by Dr. J.R. Buchanan applies not only to the convolutions, but to the general development of the brain; length gives power, or range of action, and breadth gives copiousness, or activity of manifestation. Thus a high, narrow back head indicates firmness and decision, but it is not as constant and copious in its manifestation as when it is associated with breadth. An individual having a narrow, high head, may determine readily enough upon a course of action, but he requires a longer period for its completion than one whose head is both high and broad. Such a cerebral conformation cannot accomplish its objects without enjoying regular rest, and maintaining the best of habits. Breadth of this region of the brain indicates ample resources of energy, both psychical and physical. It denotes greater vigor of constitution, one that continually generates volitive forces, and its persistency of purpose may be interpreted as functional tenacity. Inflexibility of will and purpose impart their tenacious qualities to every bodily function. The will to recover is often far more potent than medicine. We have often witnessed its power in restraining the ravages of disease. The energetic faculties, located at the upper and posterior part of the head, are the invigorating, or tonic elements of the constitution, imparting hardy, firm, steady, and efficient influences, checking excess of secretion, repressing dissipation, and tending to maintain self-possession, as well as healthy conditions of life. Fig. 90 is a portrait of U.S. Grant, which shows a well-balanced organization, with sufficient volitive elements to characterize the constitution.

Fig. 90.

The old term bilious temperament might possibly be retained [pg 173]in deference to long usage, did it not inculcate a radical error. Bilious is strictly a medical term, relating to bile, or to derangements produced by it, and it was used originally to distinguish a temperament supposed to be characterized by a predominance of the biliary secretion. In the volitive temperament, the firm, tenacious, toning, and restraining faculties repress, rather than encourage biliary secretion, and hence the necessity for administering large doses of cholagogues, remedies which stimulate the secretion of bile. When the system is surcharged with bile, from a congested condition of the liver, we use these agents in order to obtain necessary relief. In this temperament there is moderate hepatic development, lack of biliary activity, deficiency in the secretion of bile, and a sluggish portal circulation. Therefore, to apply the term bilious to this temperament is not only unreasonable, but it is calculated to mislead. The condition of the bowels is generally constipated, the skin dark and sometimes sallow. For these and other obvious reasons, we dismiss the word bilious, and substitute one which is more characteristic.

We will not dwell upon the volitive as psychical organs, except to show that, when their influence is transmitted to the body, they act as physiological organs, and thus demonstrate that all parts of the brain have their physiological, as well as mental functions. When Andrew Jackson uttered with great emphasis the memorable words, "BY THE ETERNAL," the effect was like a shock from a galvanic battery, thrilling the cells in his own body, and paralyzing with fear every one in Calhoun's organization. This is an illustration of the power or range of action of these faculties. Breadth or copiousness is illustrated in Gen. Grant's reply, "I PROPOSE TO FIGHT IT OUT ON THIS LINE, IF IT TAKES ALL SUMMER." Such a temperament has a profusion of constitutional power, great durability of the life-force, and, in our opinion, the combined height and breadth of this region correctly indicate the natural hardihood of the body and its retentiveness of life. No one need doubt its influence upon the sympathetic system, and, through that system, its power over absorption, circulation, assimilation, and secretion, as well as the voluntary processes. Mental hardihood seems wrought into concrete organization. It checks excess of glandular [pg 174]absorption, restrains the impulses of tumultuous passion, tones and regulates the action of the heart, and helps to weave the strands of organization into a more compact fabric. The toning energies of the volitive faculties are better than quinine to fortify the system against miasma or malaria, and they co-operate with all tonic remedies in sustaining organic action. Fig. 91 is a portrait of Prof. Tyndall, the eminent chemist, [pg 175]whose likeness indicates volitive innervation, showing great strength of character and of constitution; he is an earnest, thorough, and intense mental toiler; ambitious, but modest; brilliant, because persevering; diligent in scientific inquiry, and who follows the star of truth, whithersoever it may lead him. The expression of his countenance indicates his honest intentions, and displays strength of conscientious purpose; his physical constitution may be correctly interpreted in all of its general characteristics by the analysis of his energetic temperament, the great secret of his strength and success.

Fig. 91.

Fig. 92.

We desire to offer one more illustration of a marvelous blending of this temperament with large mental and emotional faculties. Fig. 92 is a representation of the martyred President Abraham Lincoln. During an eventful career, his temperament and constitution experienced marked changes, and while always distinguished for strength of purpose and corresponding physical endurance, he was governed by noble, moral faculties, manifesting the deepest sympathy for the down-trodden and oppressed, blending tenderness and stateliness without weakness, exhibiting a human kindness, and displaying a genuine compassion, which endeared him to all hearts. He was hopeful, patriotic, magnanimous even, while upholding the majesty of the law and administering the complicated affairs of government. The balances of his temperament operated with wonderful delicacy, through all the perturbating influences of the rebellion, showing by their persistence that he was never for a moment turned aside from the great end he had in view; the protection and perpetuation of republican liberty. His life exhibited a sublime, moral heroism, elements of character which hallow his name, and keep it in everlasting remembrance.

We have treated the brain, not as a mass of organs radiating from the medulla oblongata as their real center, but as two [pg 176]cerebral masses, each of which is developed around the great ventricle. We have freely applied an easy psychical and physiological nomenclature to the functions of its organs, knowing that there is no arbitrary division of them by specific number, for the cerebrum, in an anatomical sense, is a single organ. The doctrine of cerebral unity is true, and the doctrine of its plurality of function is true also. Whatever effect an organ produces when acting in entire predominance, is regarded as the function of that organ and is expressed by that name. Although our names and divisions are arbitrary and designed for convenience, yet they facilitate our consideration of the psychical, and their corresponding physiological functions. Every cerebral manifestation denotes a psychical organ, and in proportion as these acts are transmitted to the body it becomes a physiological organ. We have ventured to repeat this proposition for the sake of the non-professional reader, that he may be able to distinguish between' the two results of the manifestation of one organ. The transmission of the influence of the brain into the body enables the former to act physiologically, whereas, if its action were confined within the cranium, it would only be psychical. In the language of Prof. J.R. Buchanan, "every organ, therefore, has its mental and corporeal, its psychological and physiological functions—both usually manifested together—either capable of assuming the predominance." We have already seen to what degree the Will operates upon the organism, or how "the soul imparts special energy to single organs, so that they perform their functions with more than usual efficiency," and thus resist the solicitations of morbific agents. Doubtless our best thoughts are deeply tinged by the healthful or diseased conditions of such organs as the stomach, the lungs, the heart, or even the muscular or circulatory systems, and these impressions, when carried to the sensorium, are reflected by the thoughts, for reflex action is the third class of functions, assigned to the cerebrum. These reflex actions are either hygienic and remedial, or morbid and pernicious. Hence, it is philosophical not only to interpret the thoughts as physiological and pathological indications, but to consider the cerebrum as exerting real hygienic and remedial forces, capable of producing salutary reparative, and restorative effects. When a boiler carries more [pg 177]steam than can be advantageously employed, it is subjected to unnecessary and injurious strain, and is weakened thereby; so, when the body is overtasked by excessive pressure of the volitive faculties, it is prematurely enfeebled and broken down. There are many individuals who need to make use of some sort of safety valve to let off the surplus of their inordinate ambition; they need some kind of patent brake to slacken their speed of living; they should relieve the friction of their functional powers by a more frequent lubrication of the vital movements, and by stopping, for needed refreshment and rest, at some of the many way-stations of life.

#### THE ENCEPHALIC TEMPERAMENT.

The encephalic temperament is distinguished by prominence and breadth of the forehead, or by a full forehead associated with height and breadth at its coronal junction with the parietal bones, and extending toward the volitive region. (See Fig. 10, the space between 1 and 2 represents the coronal region, 1 indicating the frontal bone, and 2 the parietal). Prominence and great breadth of the forehead display analytical, i.e., scientific powers applicable to concretes, whereas a fair intellect, associated with a preponderating development of the coronal region, indicates analogical powers, i.e., faculties to perceive the relation and the agreement of principles. The former classifies and arranges facts, the latter invests them with moral and spiritual import. The one treats of matter, its physical properties, and chemical composition, the other of thoughts and intentions which involve right and wrong, relating to spiritual accountability. The intellect is employed upon an observable order of things, while the emotive faculties arrange the general laws of being into abstract science.

Fig. 93, a portrait of Prof. Tholuck, is a remarkable example of an encephalic organization. Figs. 72 and 79 fairly indicate the effects of undue mental activity, the intellect causing vital expenditure resulting in the devitalization of the blood. While the intellect displays keen penetration, subtle discrimination, and profound discernment, the emotions exhibit intense sensitiveness, acute susceptibility, and inspirational impressibility. [pg 178]The encephalic temperament is characterized by mental activity, great delicacy of organization, a high and broad forehead, expressive eyes, fine but not very abundant hair, great sensitiveness, refined feelings, vividness of conception, and intensity of emotion. If the brain is developed on the sides, there is manifested Ideality, Modesty, Hope, Sublimity, Imagination, and Spirituality. If the brain and forehead project, the Perceptive, Intuitive, and Reasoning faculties predominate. If it rises high, and nearly perpendicularly, Liberality, Sympathy, Truthfulness, and Sociability are manifested. When the emotive faculties are large, Faith, Hope, Love, Philanthropy, Religion, and Devotion characterize the individual. It is an artistic, creative, and aesthetic temperament, beautiful in conception and grand in expression, yet its sensitiveness is enfeebling, and its crowning excellence, when betrayed by the propensities, trails in defilement. Its purity is God-like, its debauchment, Perdition!

Fig. 93.

Fig. 94 is the likeness of Prof. George Bush. His forehead is amply developed in the region of Foresight, Liberality, Sympathy, Truthfulness, and Benevolence; his mouth expresses Amiability and Cheerfulness, and the whole face beams with [pg 179]Kindness and Generosity. This philanthropist, who is both a preacher and an author, has published several works upon theology, which distinguish him for great research and originality.

Fig. 94.

Fig. 95 represents the sanguine-encephalic temperament, the two elements being most happily blended. The portrait is that of Emmanuel Swedenborg, the great scholar and spiritual divine. The reader will observe how high and symmetrical is the forehead, and how well balanced appears the entire organization. He was remarkable for vivid imagination, great scientific acquirements, and all his writings characterize him as a subtle reasoner.

When the encephalic predominates, and the sanguine is deficient in its elements, we find conditions favorable to waste and expenditure, and adverse to a generous supply and reformation of the tissues. A child inheriting this cerebral development is already top-heavy, and supports, at an immense disadvantage, this disproportionate organization. The nutritive functions are overbalanced; consequently there is a [pg 180]predisposition to scrofulous diseases and disorders of the blood, various degenerating changes taking place in its composition; loss of red corpuscles, signified by shortness of breath; morbid changes, manifested by cutaneous eruptions; exhaustion from lack of nourishment, etc., until, finally, consumption finishes the subject.

Fig. 95.

Harmony is the support of all institutions, and applies with special cogency to the maintenance of health. When the mind dwells on one subject to the exclusion of all others, we call such a condition monomania. If we have an excessive development of mind, and deficient support of body, the result is corporeal derangement. It is unfortunate for any child to inherit unusually large brain endowments, unless he is possessed of a vigorous, robust constitution. Such training [pg 181]should be directed to that body as will encourage it to grow strong, hearty, and thrifty, and enable it to support the cerebral functions. The mental proclivities should be checked and the physical organization cultivated, to insure to such a child good health. Cut off all unnecessary brain-wastes, attend to muscular training and such invigorating games and exercises as encourage the circulation of the blood; keep the skin clean and its functions active, the body warm and well protected, the lungs supplied with pure air, the stomach furnished, with wholesome food, besides have the child take plenty of sleep to invigorate the system, and thus, by regular habits, maintain that equilibrium which tends to wholesome efficiency and healthful endurance.

#### TRANSMISSION OF LIFE.

As has been already stated in the chapter on Biology, reproduction of the species depends upon the union of a sperm-cell with a germ-cell, the male furnishing the former and the female the latter. It is a well-known fact that the marriage of persons having dissimilar temperaments is more likely to be fertile than the union of persons of the same temperaments; consanguineous marriages, or the union of persons nearly related by blood, diminish fertility and the vigor of the offspring. Upon this subject Francis Galton has given some very interesting historical illustrations in his well-known work, entitled "Hereditary Genius." The half-brother of Alexander the Great, Ptolemy I, King of Egypt, had twelve descendants, who successively became kings of that country, and who were also called Ptolemy. They were matched in and in, but in nearly every case these near marriages were unprolific and the inheritance generally passed through other wives. Ptolemy II married his niece, and afterwards his sister; Ptolemy IV married his sister. Ptolemy VI and VII were brothers, and they both consecutively married the same sister; Ptolemy VII also subsequently married his niece; Ptolemy VIII married two of his sisters in succession. Ptolemy XII and XIII were brothers, and both consecutively married their sister, Cleopatra. Mr. Galton and Sir Jas. Y. Simpson have shown that many peerages have become extinct through the evil results of inter-marriage. Heiresses are usually only children, the feeble product [pg 182]of a run-out stock, and statistics have shown that one-fifth of them bear no children, and fully one-third never bear more than one child. Sir J.Y. Simpson ascertained that out of 495 marriages in the British Peerage, 81 were unfruitful, or nearly one in every six; while out of 675 marriages among an agricultural and seafaring population, only 65 were sterile or barren, or a little less than one in ten.

While the marriages of persons closely related, or of similar temperaments are frequently unfruitful, we would not have the reader understand that sterility, or barrenness, is usually the result of such unions. It is most frequently due to some deformity or diseased condition of the generative organs of the female. In the latter part of this work may be found a minute description of the conditions which cause barrenness, together with the methods of treatment, which have proved most effectual in the extensive practice at the Invalids' Hotel and Surgical Institute.

The temperaments may be compared to a magnet, the like poles of which repel, and the unlike poles of which attract each other. Thus similarity of temperament results in barrenness while dissimilarity makes the vital magnetism all the more powerful. Marriageable persons moved by some unknown influence, have been drawn instinctively toward each other, have taken upon themselves the vows and obligations of wedlock, and have been fruitful and happy in this relation. Alliances founded upon position, money, or purely arbitrary considerations, mere contracts of convenience, are very apt to prove unhappy and unproductive.

Men may unconsciously obey strong instinctive impulses without being conscious of their existence, and by doing so, avoid those ills, which otherwise might destroy their connubial happiness. The philosophy of marriage receives no consideration, because the mind is pre-occupied with newly awakened thoughts and feelings. Lovers are charmed by certain harmonies, feel interior persuasions, respond to a new magnetic influence and are lost in an excess of rapture.

If the parties to a marriage are evenly balanced in organic elements, although both of them are vigorous, yet it is physiologically more suitable for them to form a nuptial alliance with [pg 183]an unlike combination. The cause of the wretchedness attending many marriages may be traced to a too great similarity of organization, ideas, taste, education, pursuits, and association, which similarity almost invariably terminates in domestic unhappiness. The husband and wife should be as different as the positive and negative poles of a magnet. When life is begotten under these circumstances we may expect a development bright with intelligence.

[pg 184]

## CHAPTER XVI

# MARRIAGE.

### LOVE.

> "Love is the root of creation; God's essence; worlds without number
> Lie in his bosom like children; he made them for this purpose only.
> Only to love and to be loved again, he breathed forth his spirit
> Into the slumbering dust, and upright standing, it laid its
> Hand on its heart, and felt it was warm with a flame out of heaven."
> —LONGFELLOW.

Love, that tender, inexplicable feeling which is the germinal essence of the human spirit, is the rudimental element of the human soul. It is, therefore, a Divine gift, a blessing which the Creator did not withdraw from his erring children, when they were driven from a paradise of innocence and loveliness into a world of desolation and strife. He left it as an invisible cord by which to draw the human heart ever upward, to a brighter home—the heavenly Eden. Love is the very essence of Divine law, the source of inspiration, even the fountain of life itself. It is spontaneous, generous, infinite. To its presence we are indebted for all that is good, true, and beautiful in Art and Nature. It endows humanity with countless virtues, and throws a mystic veil over our many faults. It is this feeling, this immutable law, which controls the destiny of the race. From its influence empires have fallen, scepters have been lost. Literature owes to Love its choicest gems. [pg 185]The poet's lay is sweeter when Cupid tunes the lyre. The artist's brush is truer when guided by Love. Greece was the cradle of letters and art. Her daughters were queens of beauty, fitted to inspire the Love of her noblest sons.

Fig. 96.

The materialism of the nineteenth century has sought to degrade Love; to define it as purely physical. The result has been a corresponding degradation of art, and even literature has lost much of its lofty idealism. Nudity has become a synonym of vulgarity; Love, of lust. "Evil be to him who evil thinks." True Love never seeks to degrade its object; on the contrary, it magnifies every virtue, endows it with divinest attributes, and guards its chastity, or honor, at the sacrifice of its own life. It increases benevolence by opening the lover's heart to the wants of suffering humanity. Ideality is the canvas, and imagination the brush with which Love delineates the beauties of the adored. Love heightens spirituality, awakens hope, strengthens faith, and enhances devotion. It quickens the perceptions, intensifies the sensibilities, and redoubles the memory. It augments muscular activity, and imparts grace to every movement. The desire to love and to be loved is innate, and forms as much a part of our being as bone or reason. In fact, Love may be considered as the very foundation of our spiritual existence, as bone and reason are the essential bases of our physical and intellectual being. Every man or woman feels the influence of this emotion, sooner or later. It is the Kadesh-barnea of human existence; obedience to its intuitions insures the richest blessings of life, while neglect or perversion enkindles God's wrath, even as did the disobedience of the wandering Israelites.

The one great fact which pervades the universe is action. The very existence of Love demands its activity, and, hence, the highest happiness is attained by a normal and legitimate development of this element of our being. The heart demands [pg 186]an object upon which to lavish the largess of its affection. In the absence of all others, a star, a flower, or even a bird, will receive this homage. The bird warbles a gay answer to the well-known voice, the flower repays the careful cultivator by displaying its richest tints, the star twinkles a bright "good evening" to the lonely watcher, and yet withal there is an unsatisfied longing in the lover's heart, to which neither can respond; the desire to be loved! Hence, the perfect peace of reciprocated love. If its laws are violated, nature seeks revenge in the utter depression or prostration of the vital energies. Thus has the Divine Law-giver engraven His command on our very being. To love is, therefore, a duty, the fulfillment of which should engage our noblest powers.

This emotion manifests itself in several phases, prominent among which is filial affection, the natural harmonizer of society. Paternal love includes a new element—protection. Greater than either, and second only in fortitude to maternal affection, is

#### CONJUGAL LOVE.

> "He is blest in Love alone
> Who loves for years and loves but one."—HUNT.

With Swedenborg, we may assert, "that there is given love truly conjugal, which at this day is so rare, that it is not known what it is, and scarce that it is." The same author has defined this relation to be a union of Love and Wisdom. The fundamental law of conjugal love is fidelity to one love. God created but one Eve, and the essential elements of paternal and maternal love pre-suppose and necessitate, for their normal development, the Love of one only. Again, Love is the sun of woman's existence. Only under its influence does she unfold the noblest powers of her being. Woman's intuitions should therefore be taken as the true love-gauge. If she desire a plurality of loves, it must be a law of her nature; but is communism the desire of our wives and daughters? No! Every act which renders woman dear to us, denounces such an idea and reveals the exclusive sacredness of her Love. As condemning promiscuity in this relation, we may cite the lovers' pledges and oaths of fidelity, the self-perpetuity of Love itself, [pg 187]the common instincts of mankind, as embodied in public sentiment, and the inherent consciousness that first love should he kept inviolable forever. Again, Love is conservative. It clings tenaciously to all the memories connected with its first object. The scenes consecrated to "Love's young dream" are sacred to every heart. The woodland with its winding paths and arbors, the streamlet bordered with drooping violets and dreamy pimpernel, the clouds, and even "the very tones in which we spoke," are indelibly imprinted on the memory. There is also the "mine and thine" intuition of love. This sentiment is displayed in every thought and act of the lover. Every pleasure is insipid unless shared by the beloved; selfish and exacting to all others, yet always generous and forgiving to the adored. "Mine and thine, dearest," is the language of Conjugal Love.

The consummation desired by all who experience this affection, is the union of souls in a true marriage. Whatever of beauty or romance there may be in the lover's dream, is enhanced and spiritualized in the intimate communion of married life. The crown of wifehood and maternity is purer, more divine, than that of the maiden. Passion is lost; the emotions predominate.

The connubial relation is not an institution; it was born of the necessities and desires of our nature. "It is not good for man to be alone," was the Divine judgment, and so God created for him "an helpmate." Again, "Male and female created He them;" therefore, sex is as divine as the soul. It is often perverted, but so is reason, aye, so is devotion.

The consummation of marriage involves the mightiest issues of life. It may be the source of infinite happiness or the seal of a living death. "Love is blind" is an old saying, verified by thousands of ill-assorted unions. Many unhappy marriages are traceable to one or both of two sources, Physical Weaknesses and Masquerading. Many are the candidates for marriage who are rendered unfit therefor from weaknesses of their sexual systems, induced by the violation of well-established physical laws.

We cannot too strongly urge upon parents and guardians the imperative duty of teaching those youths who look to them for [pg 188]instruction, in all matters which pertain to their future well-being such lessons as are embraced in the chapter of this book entitled, "Hygiene of the Reproductive Organs." By attending to such lessons as will give the child a knowledge of the physiology and hygiene of his whole system, the errors into which so many of the young fall, and much of the misery which is so often the dregs of the hymeneal cup, will be avoided.

Masquerading is a modern accomplishment. Girls wear tight shoes, burdensome skirts, and corsets, all of which prove very injurious to their health. At the age of seventeen or eighteen, our young ladies are sorry specimens of womankind, and "palpitators," cosmetics, and all the modern paraphernalia of fashion are required to make them appear fresh and blooming. Man is equally to blame. A devotee to all the absurd devices of fashion, he practically asserts that "dress makes the man." But physical deformities are of far less importance than moral imperfections. Frankness is indispensable in love. Each should know the other's faults and virtues. Marriage will certainly disclose them; the idol falls and the deceived lover is transformed into a cold, unloving husband or wife. By far the greater number of unhappy marriages are attributable to this cause. In love especially, honesty is policy and truth will triumph.

#### HISTORY OF MARRIAGE.

Polygamy and Monogamy. We propose to give only a brief dissertation on the principles and arguments of these systems, with special reference to their representatives in the nineteenth century. Polygamy has existed in all ages. It is, and always has been, the result of moral degradation or wantonness. The Garden of Eden was no harem. Primeval nature knew no community of love. There was only the union of two "and the twain were made one flesh." Time passed; "the sons of God saw the daughters of men that they were fair; and they took them wives of all which they chose." The propensities of men were in the ascendant, and "God repented Him that He had created man." He directed Noah to take into the ark, two of every sort, male and female. But "the imagination of man's heart is evil from his youth," and tradition points to Polygamy as the generally recognized form of marriage among the ancients. [pg 189]The father of the Hebrew nation was unquestionably a polygamist, and the general history of patriarchal life shows that a plurality of wives and concubines were national customs. In the earlier part of Egyptian history, Menes is said to have founded a system of marriage, ostensibly monogamous, but in reality it was polygamous, because it allowed concubinage. As civilization advanced, the latter became unpopular, and "although lawful, was uncommon," while polygamy was expressly forbidden. Solomon, according to polygamous principles, with his thousand women, should have enjoyed a most felicitous condition. Strange that he exclaimed "A woman among all these have I not found." According to the distinguished Rabbi, Maimonides, polygamy was a Jewish custom as late as the thirteenth century. When Cecrops the Egyptian King, came to Athens (1550, B.C.) he introduced a new system, which proved to be another step toward the recognition of Monogamy. Under this code a man was permitted to have one wife and a concubine. Here dawned the era of Grecian civilization, the glory of which was reflected in the social and political principles of Western Europe. During the fourth and fifth centuries B.C., concubinage disappeared, but, under the new regime, the condition of the wife was degraded. She was regarded as simply an instrument of procreation and a mistress of the household, while a class of foreign women, who devoted themselves to learning and the fine arts, were the admired, and often the beloved companions of the husbands. These were the courtesans who played the same role in Athenian history, as did the chaste matron, in the annals of Rome. When Greece became subject to Rome and the national characteristics of these nations were blended, marriage became a loose form of monogamy. In Persia, during the reign of Cyrus, about 560 B.C., polygamy was sustained by custom, law, and religion. The Chinese marriage system was, and is, practically polygamous, for, from their earliest traditions, we learn that although a man could have but one wife, he was permitted to have as many concubines as he desired.

In the Christian era the first religious system which incorporated polygamy as a principle was Mohammedanism. This system, which is so admirably adapted to the voluptuous [pg 190]character of the Orientals, has penetrated Western Europe, Asia, and Africa. Hayward estimated the number of its adherents to be one hundred and forty millions. The heaven of the Mohammedan is replete with all the luxuries which appeal to the animal propensities. Ravishing Houris attend the faithful, who recline on downy couches, in pavilions of pearl. On the Western Continent a system of promiscuity was practiced by the Mexicans, Peruvians, Brazilians, and the barbarous tribes of North America.

The Mormon Church was founded by Joseph Smith, and professes to be in harmony with the Bible and a special revelation to its leading Saint. According to the Mormon code, "Love is a yearning for a higher state of existence, and the passions, properly understood, are feeders of the spiritual life;" and again, "nature is dual; to complete his organization a man must marry." The leading error of Mormonism is that it mistakes a legal permission for a Divine command. The Mormon logic may be premised as follows: the Mosaic law allowed polygamy; the Bible records it; therefore, the Bible teaches polygamy.

A Mormon Saint can have not less than three wives but as many more as he can conveniently support. The eight fundamental doctrines of the Mormon Church are stated as follows: 1. God is a person with the flesh and form of a man. 2. Man is a part of the substance of God and will himself become a god. 3. Man is not created by God but existed from all eternity. 4. Man is not born in sin, and is not accountable for offenses other than his own. 5. The earth is a colony of embodied spirits, one of many such settlements in space. 6. God is president of the immortals, having under Him four orders of beings: (1.) Gods—i.e., immortal beings, possessed of a perfect organization of soul and body, being the final state of men who have lived on earth in perfect obedience to the law. (2.) Angels, immortal beings who have lived on earth in imperfect obedience to the law. (3.) Men, immortal beings in whom a living soul is united with a human body. (4.) Spirits, immortal beings, still waiting to receive their tabernacle of flesh. 7. Man, being one of the race of gods, became eligible, by means of marriage, for a celestial throne, and his household of [pg 191]wives and children are his kingdom, not only on earth but in heaven. 8. The kingdom of God has been again founded on earth, and the time has now come for the saints to take possession of their own; but by virtue, not by violence; by industry, not by force. This sect has met with stern and bitter opposition. It was successively located in New York, Ohio, Missouri, and Illinois, from the last of which it was expelled by force of arms, and in 1848 established in Utah. Its adherents number, at the present time, more than two hundred thousand.

Another organization, differing from the Mormons, in many of its radical principles, is that of the "Communists," popularly termed "Free Lovers." It is located at Lennox, Madison Co., N.Y. Its members advocate a system of "complex marriage" which they claim is instituted with a conscientious regard for the welfare of posterity. They disclaim "promiscuity," and assert that the tie which binds them together is as permanent and as sacred as that of marriage. Community of property is commensurate with freedom of Love. They define love to be "social appreciation," and this element in their code of civilization, which they deem superior to all others, is secondary to "bodily support." The principles upon which their social status is founded may be briefly summarized as follows: "Man offers woman support and love (unconditional). Woman enjoying freedom, self-respect, health, personal and mental competency, gives herself to man in the boundless sincerity of an unselfish union. State—, Communism." In this, as in all forms of polygamous marriages, love is made synonymous with sexuality, and its purely spiritual element is lost. In every instance this spiritual element should constitute the basis of marriage, which, without it, is nothing more than legal prostitution. Without it, the selfish, degrading, animal propensities run rampant, while the emotions with all their boundless sweetness lie dormant. Woman is regarded as only a plaything to gratify the animal caprice.

That Monogamy is a law of nature is evident from the fact that it fulfills the three essential conditions which form the basis of true marriage: (1.) The development of the individual (2.) The welfare of society. (3.) The reproduction of the species.

[pg 192]

#### THE DEVELOPMENT OF THE INDIVIDUAL.

PHYSICALLY. Reciprocated love produces a general exhilaration of the system. The elasticity of the muscles is increased, the circulation is quickened, and every bodily function is stimulated. The duties of life are performed with a zest and alacrity never before experienced. "It is not possible for human beings to attain their full stature of humanity, except by loving long and perfectly. Behold that venerable man! He is mature in judgment, perfect in every action and expression, and saintly in goodness. You almost worship as you behold. What rendered him thus perfect? What rounded off his natural asperities, and moulded up his virtues? Love mainly. It permeated every pore, so to speak, and seasoned every fiber of his being, as could nothing else. Mark that matronly woman. In the bosom of her family, she is more than a queen and goddess combined. All her looks and actions express the outflowing of some or all of the human virtues. To know her is to love her. She became thus perfect, not in a day or a year, but by a long series of appropriate efforts. Then by what? Chiefly in and by love, which is specifically adapted thus to develope this maturity." But all this occurs only when there is a normal exercise of the sexual propensities. Excessive indulgence in marital pleasures deadens all the higher faculties, love included, and results in an utter prostration of the bodily powers. The Creator has endowed man and woman with passions, the suppression of which leads to pain, their gratification to pleasure, their satiety to disgust. Excessive marital indulgence produces abnormal conditions of the generative organs and not unfrequently leads to incurable disease. Many cases of uterine disease are traceable to this cause.

MORALLY AND INTELLECTUALLY. In no country where the polygamous system prevails do we find a code of political and social ethics which recognizes the rights and claims of the individual. The condition of woman is that of the basest slave, a slave to the caprice and tyranny of her master. Communism raises her from the slough of slavery, but subjects her to the level of prostitution. An inevitable sequence of polygamy is a decline of literature and science. The natural tendency of [pg 193]each system is to sensualism., The blood is diverted from its normal channels and the result is a condition which may be appropriately termed mental starvation. Sensualism is in its very nature directly opposed to literary attainments or advancement. Happily there is a golden mean, an equalization of those elements which constitutes the acme of individual enjoyment.

#### THE WELFARE OF SOCIETY.

The general law of ethics, that "whatever is beneficial to the individual, contributed to the highest good of society and vice versa," applies with equal force to the hygienic conditions of marriage. Each family, like the ancient Roman household, is the prototype of the natural government under which it lives. Wherever the marriage relation is regarded as sacred, there you will find men of pure hearts and noble lives. Of all foreign nations the Germans are celebrated for their sacred regard of woman, and the duties of marriage, and all scholars from the age of Tacitus to the present day, have concurred in attributing the elevation of woman to the pure-minded Teutons. In America, the law recognizes only Monogamy; but domestic unhappiness is a prominent feature of our national life; therefore, argues the would-be free-lover, monogamy does not accord with the best interests of mankind. The fallacy lies in the first premise. Legally, our marriage system is monogamous but socially and practically it is not! Prostitution is the source of this domestic infelicity. The "mistress" sips the sweet nectar that is denied to the deceived wife. Legislators have battled with intemperance, but have done comparatively little to banish from our midst this necessary (?) evil. They recoil with disgust from this abyss of iniquity and disease. Within it is coiled a hydra-headed monster, which invades our hearthstones, contaminates our social atmosphere, and whose very breath is laden with poisonous vapors, the inexhaustible source of all evil.

The perverted appetites of mankind are mistaken for the natural desires and necessities of our being; and, accordingly, various arguments have been advanced to prove that monogamy is not conducive to social developement. It is curious that no one of these arguments refers to the health and well-being of [pg 194]the individual, thus overlooking, perhaps willfully, the great law of social economy. Even a few medical writers sometimes advocate the principles of this so-called liberalism. In a recently published work, there are enumerated only two demerits of polygamy and six of monogamy. These six demerits which the author is pleased to term a "bombshell," he introduces on account of his moral convictions no less than humanitarian considerations. The same author terms monogamy a "worm-eaten and rotten-rooted tree." The worm that is devastating the fairest tree of Eden and draining its richest juices is what our contemporary thinks, may be "plausibly termed, a necessary evil." It is claimed that monogamy begets narrow sympathies and leads to selfish idolatry. The fallacy of this argument lies in the misapprehension of the term selfishness. Self-preservation is literally selfishness, yet who will deny that it is a paramount duty of man. If perverted, it may be vicious, even criminal; but selfishness, in so far as it is generated by monogamy, is one of the chief elements of social economy; furthermore, it favors the observance of the laws of sexual hygiene. As we have said elsewhere, true love increases benevolence, and correspondingly expands and develops the sympathies. Selfish idolatry is preferable to social neglect. This argument will not bear a critical examination; for it is asserted that in a happy union, "love is so exclusive that there is hardly a liking for good neighbors, and scarcely any love at all for God." If the "good neighbors" were equally blessed, they would not suffer from this exclusiveness, and it is practically true that there is no higher incentive to love and obey our Maker than the blessing of a happy marriage.

#### THE PERPETUATION OF THE SPECIES.

The third essential object of marriage is the perpetuation of the species. The desire for offspring is innate in the heart of every true man or woman. It is thus a law of our nature, and, as such, must have its legitimate sphere. The essential features of reproduction proclaim monogamy to be the true method of procreation. Promiscuity would render the mother unable to designate the father of her children. Among lower animals, pairing is an instinctive law whenever the female is [pg 195]incapable of protecting and nourishing her offspring alone. During at least fifteen years, the child is dependent for food and clothing upon its parents, to say nothing of the requisite moral training and loving sympathy, which, in a great measure, mould its character. Fidelity to one promotes multiplication. It has been argued by the advocates of polygamy that such a system interferes with woman's natural right to maternity. Of the many marriages celebrated yearly, comparatively few are sterile. The statement that many single women are desirous of having children, would apply only to a very limited number, as it is seldom that they would be able to support children without the aid and assistance of a father. Promiscuity diminishes the number and vitiates, the quality of the human products. "Women of pleasure never give to the world sons of genius, or daughters of moral purity."

[pg 196]

## CHAPTER XVII.

# REPRODUCTION.

Every individual derives existence from a parent, which word literally means one who brings forth. We restrict the meaning of the term reproduction, ordinarily, to that function by which living bodies produce other living bodies similar to themselves. Production means to bring forth; reproduction, the producing again, or renewing. To protract individual existence, nutrition is necessary, because all vital changes are attended by wear and waste. Nutrition is always engaged in the work of reparation. Every organism that starts out upon its career of development depends upon nourishing materials for its growth, and upon this renewing process for its development. Nutrition is all the while necessary to prolong the life of the individual, but at length its vigor wanes, its functions languish, and, finally, the light of earthly life goes out. Although the single organization decays and passes away, nevertheless the species is uninterruptedly continued; the tidal wave of life surges higher on the shores of time, for reproduction is as constant and stable as the attractive forces of the planetary system.

It is a fact, that many species of the lower order of animals which once existed are now extinct. It has been asserted and denied, that fossil remains of man have been found, indicating that races which once existed have disappeared from the face of the earth. The pyramids are unfolding a wonderful history, embracing a period of forty-five hundred years, which the world of science receives as literally authentic, and admits, also, that fifty-four hundred years are probably as correctly [pg 197]accounted for. The extinction of races is not at all improbable. At the present time, the aboriginal inhabitants of this continent seem to be surely undergoing gradual extinguishment! It, therefore, seems to be possible for a weaker race to deteriorate, and finally become extinct, unless the causes of their decadence can be discovered and remedied. All people are admonished to earnestly investigate the essential conditions necessary for their continuance, for the rise and fall of nations is in obedience to natural principles and operations. Viewed from this standpoint, it is possible that a careful study of the human temperaments and their relations to reproduction may be of greater moment than has hitherto been supposed, and a proper understanding of them may tend to avert that individual deterioration, which, if suffered to become general, would end in national disaster and the extinction of the race.

Until recently, even naturalists believed that descendants were strictly like their parents in form and structure. Now it is known that the progeny may differ in both form and structure from the parent, and that these may produce others still more unlike their ancestry. But all these peculiar and incidental deviations finally return to the original form, showing that these changes have definite limits, and that the alterations observe a specific variableness, which is finally completed by its assuming again the original form. (See page 16, Figs. 2 and 3).

Reproduction may be sexual or non-sexual. In some plants and animals it is non-sexual. The propagation of species is accomplished by buds. Thus the gardener grafts a new variety of fruit upon an old stock. The florist understands how to produce new varieties of flowers, and make them radiantly beautiful in their bright and glowing colors. The bud personates the species and produces after its kind. Some of the annelides, a division of articulate animals, characterized by an elongated body, formed of numerous rings or annular segments, multiply by spontaneous division. A new head is formed at intervals in certain segments of the body. (See Fig. 97).

Something similar to this process of budding, we find taking place in a low order of animal organization. Divide the fresh water polyp into several pieces, and each one will grow into [pg 198]an entire animal. Each piece represents a polyp, and so each parent polyp is really a compound animal, an organized community of beings. Just as the buds of a tree, when separated and engrafted upon another tree, grow again, each preserving its original identity, so do the several parts of this animal, when divided, become individual polyps, capable of similar reproduction.

Fig. 97. An annelid dividing spontaneously, a new head having been formed toward the hinder part of the body of the parent.

The revolving volvox likewise increases by growth until it becomes a society of animals, a multiple system of individuals. There are apertures from the parent, by which water gains a free access to the interior of the whole miniature series. This monad was once supposed to be a single animal, but the microscope shows it to be a group of animals connected by means of six processes, and each little growing volvox exhibits his red-eye speck and two long spines, or horns. These animals also multiply by dividing, and thus liberate another series, which, in their turn, reproduce other groups.

Generation requires the concurrence of stimuli and susceptibility, and, to perfect the process, two conditions are also necessary. The first is the sperm, which communicates the principle of action; the other is the germ, which receives the latent life and provides the conditions necessary to organic evolution. The vivifying function belongs to the male, that of nourishing and cherishing is possessed by the female; and these conditions are sexual distinctions. The former represents will and understanding; the latter, vitality and emotion. The father directs and controls, the mother fosters and encourages; [pg 199]the former counsels and admonishes, the latter persuades and caresses; and their union in holy matrimony represents one; that is, the blending of vitality and energy, of love and wisdom,—the elements indispensable to the initiation of life under the dual conditions of male and female,—one in the functions of reproduction.

Let us consider the modes of Sexual Reproduction, which are hermaphroditic and dioecious.

#### HERMAPHRODITIC REPRODUCTION.

We have said that two kinds of cells represent reproduction, namely, sperm and germ-cells. These may be furnished by different individuals, or both may be found in one. When both are found in the same individual, the parent is said to be a natural hermaphrodite. A perfect hermaphrodite possesses the attributes of both male and female—uniting both sexes in one individual. Natural hermaphroditic reproduction occurs only among inferior classes of animals, and naturalists inform us that there are a greater number of these than of the more perfect varieties. These are found low in the scale of animal organization, and one individual is able to propagate the species. In the oyster and ascidians no organs can be detected in the male, but in the female they are developed. Polyps, sponges, and cystic entozoa, may also be included among hermaphrodites.

It is only very low organisms indeed in which it is a matter of indifference whether the united sperm-cells and germ-cells are those of the same individual, or those of different individuals. In more elaborate structures and highly organized beings, the essential thing in fertilization is the union of these cells specially endowed by different bodies, the unlikeness of derivation in these united reproductive centers being the desideratum for perpetuating life and power.

In other classes, as entozoa, there appear to be special provisions whereby the sperm-cells and germ-cells may be united; i.e., the male organs are developed and so disposed as to fecundate the ova of the same individual. Sexual and non-sexual modes of reproduction are illustrated by that well-defined group of marine invertebrate animals, called cirripedia Fig. 98 represents one of this genus.

[pg 200]

Fig. 98. Pollicipes Mitella.

Some of these are not only capable of self-impregnation, but likewise have what are called complemental males attache to some of the hermaphrodites. In the whole animal kingdom, it may be doubted if there exists another such class of rudimentary creatures as the parasitic males, who possess neither mouth, stomach, thorax, nor abdomen. After exerting a peculiar sexual influence, they soon die and drop off; so that in this class of animals may be found the sexual distinctions of male, female, and perfect hermaphrodites.

Fig. 99. Rotiferia; Brachionus Urceolaris; largely magnified.

There is a class of wheel-animalcules termed rotifera, of which the revolving volvox is one example. They have acquired this name on account of the apparent rotation of the disc-like organs which surround their mouths and are covered with cilia, or little hairs. They are minute creatures, and can best be viewed with a microscope, although the larger forms may be seen without such assistance. They are widely diffused on the surface of the earth, inhabit lakes as well as the ocean, and are found in cold, temperate, and tropical climates. The rotifera were once supposed to be hermaphrodites, but the existence of sexes in one species has been clearly established. The male, however, is much smaller, and far less developed than the female. In some of these species, germ-cells, or eggs, are found, which do not require fecundation for reproduction or development, so that they belong to the non-sexual class.

The third variety of hermaphrodites embraces those animals in which the male organs are so disposed as not to fecundate [pg 201]the ova of the same body, but require the co-operation of two individuals, notwithstanding the co-existence in each of the organs of both sexes. Each in turn impregnates the other. The common leech, earth-worm, and snail, propagate in this manner.

Unnatural hermaphrodism is characteristic of insects and crustaceans, in which the whole body indicates a neutral character, tending to exhibit the peculiarities of male or female, in proportion to the kind of sexual organs which predominates. Half of the body may be occupied by male, the other half by female organs, and each half reflects its peculiar sexual characteristics. Some butterflies are dimidiate hermaphrodites; i.e. one side of the body has the form and color of the male, the other the form and color of the female. The wings show by their color and appearance these sexual distinctions. The stag-beetle is also an example. We have accounts of dimidiate hermaphrodite lobster, male in one half and female in the other half of the body.

Among the numerous classes of higher animals, which have red blood, we have heard of no well-authenticated instance of hermaphrodism, or the complete union of all the reproductive organs in one individual. True, the term hermaphrodite is often applied to certain persons in whom there is some malformation, deficiency, or excess, of the genital organs. These congenital deformities consisting of combined increase or deficiency, supernumerary organs, or transposition of them, which usually render generation physically impossible, have been called bisexual hermaphrodism and classed as monstrosities. We have many published accounts of them, hence, further reference to them here is unnecessary. We would especially refer those readers who may desire to make themselves further acquainted with this interesting subject, to the standard physiological works of Flint, Foster, Carpenter, Bennett, Dalton, and others equally eminent in this particular branch of science.

Certain theories have been advanced concerning conditions which may influence the sex of the offspring. One is that the right ovary furnishes the germs for males, the left for females that the right testicle furnishes sperm capable of fecundating the germs of males, and the left testicle, the germs of the left [pg 202]ovary, for females. That fecundation sometimes takes place from right to left and thus produces these abnormal variations. We merely state the hypothesis, but do not regard it as accounting for the distinction of sex, or as causing monstrosities, though it is somewhat plausible as a theory, and is not easily disproved. In the lower order of animals, as sheep and swine, one of the testicles has been removed, and there resulted afterward both male and female progeny, so that the theory seems to lack facts for a foundation.

We sometimes witness in the child excessive development, as five fingers, a large cranium, which results in dropsical effusion, or deficient brain, as in idiots; sometimes a hand or arm is lacking, or possibly there is a dual connection, as in the case of the Siamese twins; or, two heads united on one body. It is difficult to give any satisfactory explanation of these abnormal developments. From age to age, the type is constant, and preserves a race-unity. The crossings of the races are only transient deviations, not capable of perpetuation, and quickly return again to the original stock. This force is persistent, for inasmuch as the individual represents the race, so does his offspring represent the parental characteristics, in tastes, proclivities, and morals, as well as in organic resemblances. This constancy is unaccountable, and more mysterious than the occasional malformation of germs in the early period of foetal life. If to every deviation from that original form and structure, which gives character to the productions of nature, we apply the term monster, we shall find but very few, and from this whole class there will be a very small number indeed of sexual malformations. If the sexes be deprived of the generative organs, they approach each other in disposition and appearance. All those who are partly male and partly female in their organization, unite, to a certain extent, the characteristics of both sexes. When the female loses her prolific powers, many of her sexual peculiarities and attractions wane.

#### DIOECIOUS REPRODUCTION.

Dioecious is a word derived from the Greek, and signifies two households; hence, dioecious reproduction is sexual generation by male and female individuals. Each is distinguished by sexual [pg 203]characteristics. The male sexual organs are complete in one individual, and all the female organs belong to a separate feminine organization. In some of the vertebrates, impregnation does not require sexual congress; in other words, fecundation may take place externally. The female fish of some species first deposits her ova, and afterwards the male swims to that locality and fertilizes them with sperm.

In higher orders of animals, fecundation occurs internally, the conjunction of the sperm and germ cells requiring the conjugation of the male and female sexual organs. The sperm-cells of the male furnish the quickening principle, which sets in play all the generative energies, while the germ-cell, susceptible to its vivifying presence, responds with all the conditions necessary to evolution. The special laboratory which furnishes spermatic material is the testes, while the stroma of the ovaries contributes the germ-cell. Several different modes of reproducing are observed when fecundation occurs within the body, which vary according to the peculiarities and organization of the female.

Modes of Dioecious Reproduction.—A very familiar illustration of one mode is found in the common domestic fowl, the egg of which vivified within the ovarium, is afterward expelled and hatched by the simple agency of warmth. This mode of reproduction is called oviparous generation.

The ovaries, as well as all their latent germs, are remarkably influenced by the first fecundation. It seems to indicate monogamy as the rule of higher sexual reproduction. The farmer understands that if he wishes to materially improve his cows, the first offspring must be begotten by a better, purer breed, and all that follow will be essentially benefited, even if not so well sired. Neither will the best blood exhibit its most desirable qualities in the calves whose mothers have previously carried inferior stock. So that there are sexual ante-natal influences which may deteriorate the quality of the progeny. The Jews understood this principle, in the raising up of sons and daughters unto a deceased brother. The fact that the sexual influence of a previous conception is not lost, is illustrated when, in a second marriage, the wife bears a son or daughter resembling bodily or mentally, or in both of these respects the former [pg 204]husband. This indicates a union for life by natural influences which never die out.

With some species of fish and reptiles, the egg is impregnated internally, and the process of laying commences immediately, but it proceeds so slowly through the excretory passages, that it is hatched and born alive. This is called ovo-viviparous generation.

As we rise in the scale of organization, animals are more completely developed, and greater economy is displayed in their preservation. The germ passes from the ovary into an organ prepared for its reception and growth, to which, after fecundation, it becomes attached, and where it remains until sufficiently developed to maintain respiratory life. This organ is called the womb, or uterus, and is peculiar to most mammalia. This mode of reproduction is termed viviparous generation.

The kangaroo and oppossum are provided with a pouch attached to the abdomen, which receives the young born at an early stage of development. They remain in contact with the mammæ, from which they obtain their nourishment, until their growth is sufficiently completed to maintain an independent existence. This is called marsupial generation. The variety of reproduction which is most interesting, is that of the human species, and is called viviparous generation. It includes the functions of copulation, fecundation, gestation, parturition, and lactation.

For the full and perfect development of mankind, both mental and physical chastity is necessary. The health demands abstinence from unlawful intercourse. Therefore children should not be allowed to read impure works of fiction, which tend to inflame the mind and excite the passions. Only in total abstinence from illicit pleasures is there moral safety and health, while integrity, peace, and happiness, are the conscious rewards of virtue. Impurity travels downward with intemperance, obscenity, and corrupting diseases, to degradation and death. A dissolute, licentious, free-and-easy life is filled with the dregs of human suffering, iniquity, and despair. The penalties which follow a violation of the law of chastity are found to be severe and swiftly retributive.

[pg 205]

Fig. 100. Male

Fig. 101. Female

[pg 206]

Fig. 102. Outline of the Female Urinary and Generative Organs.

The union of the sexes in holy matrimony is a law of nature finding sanction in both morals and legislation. Even some of the lower animals unite in this union for life, and instinctively observe the law of conjugal fidelity with a consistency which might put to blush other animals more highly endowed. It is important to discuss this subject and understand our social evils, as well as the unnatural desires of the sexes, which must be controlled or they lead to ruin. Sexual propensities are possessed by all, and they must be held in abeyance, until they are exercised for legitimate purposes. Hence parents ought to understand the value of mental and physical labor to elevate and strengthen the intellectual and moral faculties of their children, to develop the muscular system and direct the energies of the blood into healthful channels. Vigorous employment [pg 207]of mind and body engrosses the vital energies and diverts them from undue excitement of the sexual desires.

Fig. 103. Outline of the Male Reproductive Organs.

Sexual generation by pairing individuals is the most economical mode of propagating the species. The lower orders of animals possess wonderful multiplicative powers and their faculty for reproduction is offset by various destructive forces. The increased ability for self-maintenance implies diminished reproductive energy; hence the necessity for greater economy and safety in rearing the young. As certain larvæ and insects increase, the birds which feed upon them become more numerous. When this means of support becomes inadequate, these same birds diminish in number in proportion to the scarcity of their food. Many have remarked that very prolific seasons are followed by unusual mortality, just as periods of uncommon prosperity precede those of severe disaster.

The increased mental and moral cultivation of mankind imposes upon them the necessity for greater physical culture. [pg 208]"Wiser and weaker," is a trite saying, and means that the exercise of the higher nature discloses the equivalent necessity of culturing the body, in order to support the increasing expenditures of the former. Mental and moral discipline are essential for a proper understanding how to provide for the body, for physical training increases the capacity of the individual for self-preservation. Constant vigilance is the price of health as well as of liberty.

It is an interesting physiological fact that, while the growth and development of the individual are rapidly progressing, the reproductive powers remain almost inactive, and that the commencement of reproduction not only indicates an arrest of growth, but, in a great measure, contributes toward it. From infancy to puberty, the body and its individual organs, structurally as well as functionally, are in a state of gradual and progressive evolution. Men and women generally increase in stature until the twenty-fifth year, and it is safe to assume that perfection of function is not established until maturity of bodily development is completed. Solidity and strength are represented in the organization of the male, grace, and beauty in that of the female. His broad shoulders represent physical power and the right of dominion, while her bosom is the symbol of love and nutrition. The father encounters hardships, struggles against difficulties, and braves dangers to provide for his household; the mother tenderly supplies the infant's wants, finding relief and pleasure in imparting nourishment, and surrounds helpless infancy with an affection which is unwearied in its countless ministering attentions. Her maternal functions are indicated by greater breadth of the hips. Physical differences so influence their mental natures, that, "before experience has opened their eyes, the dreams of the young man and maiden differ." The development of either is in close sympathy with their organs of reproduction. Any defect of the latter impairs our fair ideal, and detracts from those qualities which impart excellence, and crown the character with perfections. Plainly has Nature marked out, in the organization, very different offices to be performed by the sexes, and has made these distinctions fundamental.

Likewise, Nature expresses the intention of reproduction [pg 209]by giving to plants and animals distinctive organs for this purpose. These are endowed with exquisite sensibility, so that their proper exercise produces enjoyment beneficial to both. Excessive sexual indulgence not only prostrates the nervous system, enfeebles the body, and drains the blood of its vivifying elements, but is inconsistent with intellectual activity, morality, and spiritual development. The most entrancing delights and consummate enjoyments are of the emotive order, ideal, abstract, and pure, so inspiring that they overpower the grosser sensual pleasures and diffuse their own sweet chastity and refining influence over all the processes of life.

Hence, the gratification of the sexual instincts should always be moderate. It should be regulated by the judgment and will, and kept within the bounds of health. No person has a moral right to carry this indulgence so far as to produce injurious consequences to either party, and he who cannot refrain from it is in no proper condition to propagate his species. In all culture there must be self-control, and the practice of self-denial at the command of love and justice is always a virtue. Self-government is the polity of our people, and we point with pride and laudable exultation to our political maxims, laws, and free institutions. The family is the prototype of society. If self-restraint be practiced in the marital relation, then the principle of self-control will carry health, strength, and morality into all parts of the commonwealth. The leading characteristics of any nation are but the reflection of the traits of its individual members, and thus the family truly typifies the practical morality and enduring character of a people.

#### OVULATION.

The Ovaries are those essential parts of the generative system of the human female in which the ova are matured. There are two ovaries, one on each side of the uterus, and connected with it by the Fallopian tubes; they are ovoidal bodies about an inch in diameter, and furnish the germs or ovules. These latter are very minute, seldom measuring 1/120 of an inch in diameter, and frequently are not more than half that size. The ovaries develop with the growth of the female, so that, finally, at the pubescent period, they ripen and liberate [pg 210]an ovum, or germ vesicle, which is carried into the uterine cavity through the Fallopian tubes. With the aid of the microscope, we find that these ova are composed of granular substance, in which is found a miniature yolk surrounded by a transparent membrane, called the zona pellucida. This yolk contains a germinal vesicle in which can be discovered a nucleus, called the germinal spot. The process of the growth of the ovaries is very gradual, and their function of ripening and discharging an ovum every month into the Fallopian tubes and uterus is not developed until between the twelfth and fifteenth years.

This period, which indicates, by the feelings and ideas, the desires and will, that the subjects are capable of procreation, is called puberty. The mind acquires new and more delicate perceptions, the person becomes plumper, the mammæ enlarge, and there is grace and perfection in every movement, a conscious completeness for those relations of life for which this function prepares them. The period of puberty is also indicated by

#### MENSTRUATION.

The catamenial discharge naturally follows the ripening and liberation of an ovum, and as the ovaries furnish one of these each month, this monthly flow is termed the menses (the plural of the Latin word mensis, which signifies a month). The menstrual flow continues from three to five days, and is merely the exudation of ordinary venous blood through the mucous lining of the cavity of the uterus. At this time, the nervous system of females is much more sensitive, and from the fact that there is greater aptitude to conception immediately before and after this period, it is supposed that the sexual feeling is then the strongest. When impregnation occurs immediately before the appearance of the menses, their duration is generally shortened, but not sufficiently to establish the suspicion that conception has taken place. The germ is the contribution of the female, which provides the conditions which only require the vivifying principle of the sperm for the development of another being. The period of aptitude for conception terminates at the time both ovulation and menstruation cease, [pg 211]which, unless brought about earlier by disease, usually occurs about the forty-fifth year of her age.

#### FECUNDATION.

Since in the beginning God created male and female, and said unto them, "Be fruitful, and multiply, and replenish the earth," it is evident that what was originated by creation must be continued by procreation. The process of generation the reader will find described on pages 12 and 13. Then commences a wonderful series of transforming operations, rudimentary changes preliminary to the formation of tissues, structures and functions, which finally qualify the organism for independent existence. The ovum, when expelled from the ovary, enters the fimbriated, or fringe-like extremity of the Fallopian tube, to commence at once its descent to the uterus. The process of passing through this minute tube varies in different animals. In birds and reptiles, the bulk of the expelled ova is so great as to completely fill up the tube, and it is assisted in its downward course, partly by its own weight and partly by the peristaltic action of the muscular coat of the canal. In the human subject, however, the ova are so minute that nature has supplied a special agent for their direct transmission; otherwise they might be retained, and not reach their destination. Accordingly, the fimbriated, trumpet-shaped extremity of the Fallopian tubes, which is nearest to the ovaries, and, consequently from the ovary first receives the ovum when expelled; is provided with a series of small hairs, termed cilia, forming the lining or basement membrane of the tubes, and, the movements of these cilia being towards the uterus, transmit, by their vibrating motion, the ovum from the ovary, through the Fallopian tubes, to the uterus.

The mature ovum, however, is not by itself capable of being converted into the embryo. It requires fecundation by the spermatic fluid of the male, and this may take place immediately on the expulsion of the ovum from the ovary, or during its passage through the Fallopian tube, or, according to Bischoff, Coste, and others, in the cavity of the uterus, or even upon the surface of the ovary. Should impregnation, however, fail, the ovum gradually loses its vitality, and is eventually [pg 212]expelled by the uterine secretions. It occasionally happens that the descent of the impregnated ovum is arrested, and the formation of the embryo commences in the ovary. This is termed ovarian pregnancy. Or again, the ovum may be arrested in its passage through the Fallopian tube, causing what is termed tubal pregnancy; or, after it has been expelled from the ovary, it may fail to be received by the fimbriated extremity, and escape into the cavity of the abdomen, forming what has been termed ventral pregnancy. If the microscopic germ lodges in some slight interstice of fiber, during its passage through the walls of the uterus, it may be detained long enough to fix itself there, and when this occurs, it is termed interstitial pregnancy. All these instances of extra-uterine pregnancy may necessitate the employment of surgical skill, in order that they may terminate with safety to the mother. Their occurrence, however, is very rare.

The intense nervous excitement produced by the act of coition is immediately followed by a corresponding degree of depression, and a too frequent repetition of it is necessarily injurious to health. The secretions of the seminal fluid being, like other secretions, chiefly under the influence of the nervous system, an expenditure of them requires a corresponding renewal. This renewal greatly taxes the corporeal powers, inducing lassitude, nervousness, and debility. It is a well known fact that the highest degree of mental and bodily vigor is inconsistent with more than a moderate indulgence in sexual intercourse.

To ensure strength, symmetry, and high intellectual culture in the human race, requires considerable care. Consideration should be exercised in the choice of a companion for life. Constitutional as well as hereditary ailments demand our closest attention. Age has also its judicious barriers. As before stated, when reproduction commences, growth, as a rule, ceases, therefore, it is inexpedient that matrimony should be consummated before the parties have arrived at mature stature.

#### PREVENTION OF CONCEPTION.

Much has been written upon the question whether married people have a right to decline the responsibilities of wedlock. [pg 213]The practice of inducing abortion is not only immoral but criminal, because it is destructive to both the health of the mother and the life of the embryo being. If both the parties to a marriage be feeble, or if they be not temperamentally adapted to each other, so that their children would be deformed, insane, or idiotic, then to beget offspring would be a flagrant wrong. If the mother is already delicate, possessing feeble constitutional powers, she is inadequate to the duties of maternity, and it is not right to lay such burdens upon her. Self-preservation is the first law of nature, which all ought to respect. The woman may be able to discharge the duties of a loving wife and companion, when she cannot fulfill those of child-bearing. If the husband love his wife as he ought, he will resign all the pleasure necessary to secure her exemption from the condition of maternity. It seems to us, that it is a great wickedness, unpardonable even, to be so reckless of consequences, and so devoid of all feeling, as to expose a frail, feeble, affectionate woman to those perils which almost insure her death. To enforce pregnancy under such circumstances is a crime. Every true man, therefore, should rather practice self-control and forbearance, than entail on his wife such certain misery, if not danger to life.

Undoubtedly, the trial is great, but if a sacrifice be required, let the husband forbear the gratification of passions which will assuredly be the means of developing in his delicate wife symptoms that may speedily hurry her into a premature grave. Before she has recovered from the effects of bearing, nursing, and rearing one child, ere she has regained proper tone and vigor of body and mind, she is unexpectedly overtaken, surprised by the manifestation of symptoms which again indicate pregnancy. Children thus begotten are not apt to be hardy and long-lived. From the love that parents feel for their posterity, from their wishes for their success, from their hopes that they may be useful from every consideration for their future well-being, let them exercise precaution and forbearance, until the wife becomes sufficiently healthy and enduring to bequeath her own vital stamina to the child she bears.

From what has been said on this subject, it behooves the prudent husband to weigh well the injurious, nay criminal [pg 214]results which may follow his lust. Let him not endanger the health, and it may be the life, of his loving and confiding wife through a lack of self-denial. Let him altogether refrain, rather than be the means of untold misery and, perhaps, the destruction of the person demanding his most cherished love and protection. On so important a subject, we feel we should commit an unpardonable wrong were we not to speak thus plainly and openly. An opportunity has been afforded us, which it would be reprehensible to neglect. We shall indeed feel we have been amply rewarded, if these suggestive remarks of ours tend in any way to remove or alleviate the sufferings of an uncomplaining and loving wife. Our sympathies, always susceptible to the conditions of sorrow and suffering, have been enlisted to give faithfully, explicitly, and plainly, warnings of danger and exhortations to prudence and nothing remains for us but to maintain the principles of morality, and leave to the disposal of a wise and overruling Providence the mystery of all seemingly untoward events. In every condition of life, evils arise, and most of those which are encountered are avoidable. Humanity should be held accountable for those evils which it might, but does not shun.

By a statute of the national government, prevention of pregnancy is considered a punishable offense; whereas every physician is instructed by our standard writers and lecturers on this subject, that not only prevention is necessary in many instances, but even abortion must sometimes be produced in order to save the mother's life. As we view the matter, the law of the national government asserts the ruling principle, and the exceptions to it must be well established by evidence, in order to fully justify such procedure. The family physician may, with the concurrence of other medical counselors, be justified, in rare cases, in advising means for the prevention of conception, but he should exercise this professional duty only when the responsibility is shared by other members of the profession, and the circumstances fully and clearly warrant such a practice.

After fecundation, the length of time before conception takes place is variously estimated. Should impregnation occur at the ovary or within the Fallopian tubes, usually about a week [pg 215]elapses before the fertilized germ enters the uterus, so that ordinarily the interval between the act of insemination and that of conception varies from eight to fourteen days.

#### DOUBLE CONCEPTION.

If two germs be evolved simultaneously, each may be impregnated by spermatozoa, and a twin pregnancy be the result. This is by no means a rare occurrence. It is very unusual, however, to have one birth followed by another after an interval of three or four months, and each babe present the evidences of full maturity. Perhaps such occurrences may be accounted for on the supposition that the same interval of time elapses between the impregnation of the two germs as there is difference observed in their birth; that after the act of insemination, sperm was carried to each ovary; that one had matured a germ ready for fecundation, then impregnation and conception immediately followed, and the decidua of the uterus hermetically sealed both Fallopian tubes, and thus securely retained the sperm within the other Fallopian canal. The stimulus of the sperm so pent up causes that ovary to mature a germ, although it may do so slowly, and after two or three months it is perfected, fertilized, and a second conception occurs within the uterus. If each embryo observe a regular period of growth and each be born at maturity, there must be an interval of two or three months between their births. But it is far more common for the parturition of the first, displaying signs of full maturity, to coincide with the birth of a second which is immature and which cannot sustain respiratory life. The birth of the latter is brought about prematurely, by the action of the uterus in expelling the matured child.

#### UTERINE PREGNANCY.

There are many who manifest a laudable desire to understand the physiology of conception, the changes which take place, and the order of their natural occurrence. When impregnation takes place at the ovaries or within the Fallopian tubes, there is exuded upon the inner surface of the womb a peculiar nutritious substance. It flows out of the minute porous openings surrounding the termination of the Fallopian tube within [pg 216]the uterine cavity, and, thus, is in readiness to receive the germ, and retain it there until it becomes attached. Undoubtedly, the germ imbibes materials from this matter for its nurture and growth. This membranous substance is termed the decidua, and disappears after conception is insured. Two membranes form around the embryo; the inner one is called the amnion, the outer one the chorion. Both serve for the protection of the embryo, and the inner one contains the liquor amnii, in which it floats during intra-uterine life. Immediately after conception, the small glands in the neck of the uterus usually throw out a sticky secretion, filling the canal, or uniting its sides, so that nothing can enter or leave the uterine cavity.

The fertilized ovum rapidly develops. After its conception it imbibes nourishment, and there is a disposition in fluids to pass into it, through its delicately-organized membranes. If this process is not involuntary, it is, at all events, at the convenience and use of the developing germ. After three months the embryo is termed the foetus. Its fluids are then so much more highly organized, that some of them are tinged with sanguine hues, and thenceforward acquire the characteristics of red blood. Out of red blood, blood-vessels are formed, and from the incipient development of the heart follow faint lines of arteries, and the engineers of nutrition survey a circulatory system, perfecting the vascular connections by supplementing the arteries with a complete net-work of veins and capillaries.

#### THE PLACENTA OR AFTERBIRTH.

Whenever conception occurs, a soft, spongy substance is formed between the uterus and the growing ovum, called the placenta. It is composed of membrane, cellular tissue, blood-vessels, and connecting filaments. The principal use of this organ seems to be to decarbonate the blood of the foetus, and to supply it with oxygen. It performs the same function for the foetus that the lungs do for the organism after birth. It allows the blood of the foetus to come into very close contact with that of the mother, from which it receives a supply of oxygen, and to which it gives up carbonic acid. This interchange of gases takes place in the placenta, or between it and the uterus, through the intervening membranes. This [pg 217]decarbonating function requires the agency of the maternal lungs, for the purpose of oxygenating the mother's blood.

The placenta is attached to the uterus by simple adhesion. True, in some instances, morbid adhesion takes place, or a growing together in consequence of inflammation, but the natural junction is one merely of contact, the membranes of the placenta spreading out upon the cavity of the uterus, so that, finally, the former may be entirely removed without a particle of disturbance or injury to the latter. Formerly, it was supposed that the placental vessels penetrated into the substance of the uterus. We know now there is no such continuation of the vessels of the one into the other. The decarbonation of the blood requires the placental and uterine membranes to be in contact with each other.

If the union were vascular, the mother's blood would circulate in the foetal body, and the impulses of the maternal heart might prove too strong for the delicate organism of the embryo. Besides, the separation of the placenta from the uterus might prove fatal to both parent and offspring. The placenta is only a temporary organ, and when its functions are no longer required, it is easily and safely removed.

#### THE UMBILICAL CORD.

The foetal blood is transmitted to and fro between the body of the child and the placenta, by a cord which contains two arteries and one vein. This is called the umbilical cord, because it enters the body at the middle of the abdominal region, or umbilicus. It is composed, also, of its own proper membranous sheath, or skin, and cellular tissues, besides the blood-vessels. Two months after pregnancy, this cord can be seen, when it commences to grow rapidly.

#### QUICKENING.

Not until the mother feels motion is she said to be quick with child. That is, the child must be old and strong enough to communicate a physical impulse, which the mother can distinctly perceive, before it is regarded as having received life. This is a fallacy, for the germ has to be endowed with life before organization can begin. The act of impregnation [pg 218]communicates the vital principle, and from that moment it starts upon its career of development. A long period elapses after this occurs before it can make the mother feel its motions. Before quickening, the attempt to destroy the foetus is not considered so grave a crime by our laws, but after this quickening takes place, it is deemed a felony.

#### THE RIGHT TO TERMINATE PREGNANCY.

The expediency and the moral right to prematurely terminate pregnancy must be admitted when weighty and sufficient reasons for it exist. Such a course should never be undertaken, however, without the advice and approval of the family physician, and, whenever it is possible, the counsel of another medical practitioner should be obtained. There may be so great a malformation of the pelvic bones as to preclude delivery at full term, or, as in some instances, the pregnant condition may endanger the life of the mother, because she is not able to retain nourishment upon the stomach. In such cases only, is interference warranted, and even then the advice of some well-informed physician should be first obtained, to make sure that the life of the mother is endangered before so extreme a measure is resorted to.

Those who are qualified for maternal duties should not undertake to defeat the intentions of nature, simply because they love ease and dislike responsibility. Such persons may be considered genteel ladies, but, practically, they are indifferent to the claims of society and posterity. How such selfishness contrasts with the glorious, heroic, Spartan spirit of the young woman who consulted us in reference to the acceptance of a tempting offer of marriage! She was below medium size and delicately organized. She hesitated in her answer, because she was uncertain as to her duty to herself, and to her proposed husband, and on account of the prospective contingencies of matrimony. After she was told that it was doubtful whether she could discharge the obligations of maternity with safety to herself, and yet that she might prove to her intended husband a true and valuable wife, she quickly answered, her black eyes radiant with the high purpose of her soul: "If I assent to this offer, I shall accept the condition and its consequences [pg 219]also, even if pregnancy be my lot and I know it will cost me my life!" She acceded to the proposal, and years found them one in happiness; then a daughter was born, but the bearing and nursing were too much for her delicate constitution, and she continued to sink until she found rest in the grave. Of all her beautiful and noble sayings, none reflect more moral grandeur of spirit than the one in which she expressed her purpose to prove true to posterity.

#### THE SIGNS OF PREGNANCY.

The symptoms which indicate pregnancy are cessation of the menses, enlargement of the mammæ, nausea, especially in the morning, distention of the abdomen, and movement of the foetus. A married woman has reason to suspect that she may have conceived, when, at the proper time, she fails to menstruate, especially when she knows that she is liable to become pregnant. A second menstrual failure strengthens this suspicion, although there are many other causes which might prevent the appearance of the menses, such as disease of the uterus, general debility, or taking cold, and all of these should be taken into account. In the absence of all apparent influences calculated to obstruct the menses, the presumption ordinarily is that pregnancy is the cause of their non-appearance. The evidence is still more conclusive when the mammæ and abdomen enlarge after experiencing morning sickness. Notwithstanding all these symptoms, the audible sound of the heart, or the movements of the foetus, are the only infallible signs of a pregnant condition.

#### THE DURATION OF PREGNANCY.

The ordinary duration of pregnancy is about forty weeks, or 280 days. It is difficult to foretell exactly when a pregnancy will be completed, for it cannot be known precisely when it began. Some gestations are more protracted than others, but the average duration is the time we have given. A very reasonable way to compute the term, is to reckon three months back from the day when the menses ceased and then add five days to that time, which will be the date of the expected time of confinement. It is customary, also, for women to [pg 220]count from the middle of the month after the last appearance of the menses, and then allow ten lunar months for the term. This computation generally proves correct, except in those instances in which conception takes place immediately before the fast appearance of the catamenia. A few women can forecast the time of labor from the occurrence of quickening, by allowing eighteen weeks for the time which has elapsed since conception, and twenty-two more for the time yet to elapse before the confinement. With those in whom quickening occurs regularly in a certain week of pregnancy, this calculation may prove nearly correct.

The English law fixes no precise limit for the legitimacy of the child. In France a child is regarded as lawfully begotten if born within three hundred days after the death or departure of the husband. There are a sufficient number of cases on record to show that gestation may be prolonged two, and even three, weeks beyond the ordinary, or average term. The variation of time may be thus accounted for: after insemination, a considerable interval elapses before fecundation takes place, and the passage of the fertilized germ from the ovary to the uterus is also liable to be retarded. There are many circumstances and conditions which might serve to diminish its ordinary rate of progress, and postpone the date of conception. This would materially lengthen the apparent time of gestation.

It is likewise difficult to determine the shortest period at which gestation may terminate, and the child be able to survive. A child may be born and continue to live for some months, after twenty-four or twenty-five weeks of gestation; it was so decided, at least, in an ecclesiastical trial.

We have not the space to describe minutely, or at length, the formation and growth of the foetal structures, and trace them separately from their origin to their completion at the birth of the child. The student of medicine must gain information by consulting large works and exhaustive treatises on this interesting subject.

What trifling contingencies defeat vitality! Conception may be prevented by acrid secretions, the result of disease of the reproductive organs. Leucorrheal matter may destroy the vitalizing power of the sperm-cells. There are many ways, even [pg 221]after impregnation, of compromising the existence of the frail embryo. Accidents, injuries, falls, blows, acute diseases, insufficient nutrition and development, in fact, a great variety of occurrences may destroy the life of the embryo, or foetus. After birth, numerous diseases menace the child. By what constant care must it ever be surrounded, and how often is it snatched from the very jaws of death!

What, then, is man but simply a germ, evolving higher powers, and destined for a purer and nobler existence! His latent life secretly emerges from mysterious obscurity, is incarnated, and borne upon the flowing stream of time to a spiritual destination—to realms of immortality! As he nears those ever-blooming shores, the eye of faith, illuminated by the inspired word, dimly discerns the perennial glories. Quickened by Faith, Hope, and Love, his spirit is transplanted into the garden of paradise, the Eden of happiness, redeemed, perfected, and made glorious in the divine image of Him who hath said, "I am the Way, the Truth, and the LIFE."

[pg 222]

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