HOW TO STUDY ANATOMY

“An accurate and practical knowledge of the mechanism of the human body lies at the foundation of true success in the pursuit of the profession of medicine. It is of the utmost importance, therefore, that you should at the outset adopt a plan of study which, while it fascinates, and thus absorbs all your attention, tends also powerfully to fix firmly in your memory the associated relations of function and structure. It is only when these relations are so thoroughly grasped and retained by the mind that structure at once suggests function, and function suggests structure, that anatomy is made available in all the emergencies of the daily practise of medicine and surgery.PBE 152.3

“It can not be denied that the present method of studying anatomy does not, as a rule, accomplish this result. How rarely does a student become so interested in the study of anatomy that in his zeal in its pursuit he neglects his other studies, or sacrifices pleasures and amusements! And, what is more important, how seldom do we meet a practitioner who can readily recall the precise anatomy and functions of even the more important organs and structures of the body! If we examine critically the modern text-books on anatomy, for the purpose of determining their adaptation to the twofold purpose of inspiring the student with a genuine love of the science and of rendering his knowledge instantly available in practise, we shall be convinced that they accomplish neither result; nor is it difficult to explain the cause of failure. The course of study is entirely wanting in that system, or orderly and logical development of the structures of the body, which appeals to the inventive and constructive faculties. Instead of being treated as an entity, in which each organ and structure contributes in due proportion to the completed apparatus, the several parts are studied in a fragmentary and disconnected manner, which necessarily fails to interest even the most inventive genius. The fact is entirely lost sight of that anatomy is a natural science, and that, like all natural sciences, it has a perfectly logical development, which, when properly unfolded, leads the mind insensibly from the study of simple parts to their arrangement into complex forms, as is abundantly illustrated in the science of botany, or chemistry, or biology. But neither text-books on anatomy nor teachers of this fundamental branch of a medical education adopt the natural system of teaching this science. On the contrary, the scheme of study is so arranged as to prevent associated relations, and hence continuity of thought, on the part of the student. Therefore, he is constantly required to memorize abstract facts having no necessary connection with each other. Take, for example, the experience of a medical student in attendance at one of our most advanced medical colleges during the last year: He states that his first lesson in anatomy was a description of the external parts of the clavicle; the second was a similar description of the scapula; the third was a similar study of the femur. Meantime he had learned nothing of the structure of bones, nor of their purposes in the skeleton. When questioned, he was found to be impressed with the belief that his success as a student depended solely upon his ability to retain and promptly repeat the terms which he found in his text-book. The wonderful organism which he was studying had no more attractions for him than would a language. to a student who, in learning it, was required first to commit its dictionary to memory. The prevalent method of pursuing anatomy might be compared to the study of a cotton mill, by beginning with a spindle, and learning all of its parts, than examining a distant wheel, and committing to memory every minute detail of its construction, next learning all the peculiar names of a section of its framework, and thus proceeding until the entire machine had been studied in detached fragments. It is evident that no student would become thoroughly interested in such a study, nor would his knowledge of the machinery make him an expert engineer. He might be able to answer every question involving mere book terms, and yet have very little useful or usable information if he were called upon to remedy defects in its machinery.PBE 153.1

“But an experience of many years in teaching anatomy convinced me that a course of study may be followed which will thoroughly interest the average student from the first, and enable him readily to acquire, and firmly to retain in his memory, the minutest details of function and structure of tissues. How then should anatomy be studied? I answer, precisely as you would begin, continue, and finish the study of any other mechanism with the structure and functions of which you wished to become as familiar as was the inventor. It is evident that to obtain such accurate knowledge of any machine you must study it along the lines pursued by the inventor in the development of its several parts. This would require that you should place yourselves in such relations to him as to think his thought from his first conception of the needs of such an apparatus or organism to its completion in the perfected instrument. And herein lies the charm and fascination in the study of anatomy, if you adopt that logical method which the inventor pursues in the creation of a machine. From the very beginning of your studies you would be led to think the thought of the Creator, and as the wonderful mechanism of the human body was gradually unfolded, you would become more and more inspired with the loftiest conceptions of the divine wisdom and power. The psalmist, in contemplating the evidence of design in creation, sang, ‘How precious also are Thy thoughts unto me, O God! how great is the sum of them!’PBE 155.1

“It can not be doubted that the best instructor of a person who is about to study a machine so thoroughly that he can become its engineer would be the inventor himself, for while describing his own work, he would naturally become very enthusiastic and give the most accurate and detailed account of the inception, development, and completion of his invention. As the student followed the train of thought, he would catch the inspiration of the inventor, and as each new feature of the structure gradually developed in orderly and logical succession, his mind would be aglow with the enthusiasm of his teacher, and he would be insensibly transformed into an inventor, architect, creator, and, quite unconsciously, the thing studied would become his own. Such a scheme would lead the student to begin with the inventor’s first conception of the machine about to be invented. That conception is always preceded by a recognition of a function to be performed, and the absence of any apparatus or organism to perform it. In other words, the universal law governing inventions requires that the function to be performed must first be recognized before the structure is devised. The history of every invention shows that it grew out of a recognized need of a machine to accomplish a given object, and that in its construction each part was so devised that, while it performed a special function of its own, it contributed a force or factor to the completed mechanism necessary to the successful performance of its grand purpose. We may, and should, apply the same method to the study of the structure of the human body. We should first recognize fully the function to be performed before we undertake to construct the apparatus adapted to its performance. Herein lies the secret of the successful invention of every useful mechanism. The student who enters upon and steadily pursues the study of anatomy in this spirit is from the first an inventor, and is constantly recognizing functions to be performed. and is as constantly bending all his energies to devise structural appliances to perform those functions. He not only enters into the thoughts of the Creator, but he becomes himself a creator. Thus a genuine inspiration stimulates every inventive faculty of his mind, and instead of being a mere passive agent, receiving and storing away in his memory dry and often worthless technical terms, he becomes an aggressive inquirer and explorer in this new field of science.PBE 156.1

“Now, a course of study of anatomy so arranged that the student is from the first brought into such immediate relations with the Creator of the human mechanism that he will think His thoughts, presupposes that the Creator entered upon, proceeded with, and concluded His work according to the methods which govern all inventions. That is, the Creator discovered a want in creation, a function unperformed, and forthwith proceeded to invent an instrument to meet that want and perform that function. In adopting this theory, we must assume the direct creation of man as a new and original creature, specifically adapted in every structure for a given purpose, and our study must be along the lines already indicated viz.: First of all learn the function to be performed by this new creation, and then follow the development of structure to its completion in the perfected organism.PBE 158.1

“The criticism which will be made upon this scheme of study is evident. It will be alleged that we ignore the modern theory of evolution, and thus inculcate antiquated ideas in regard to creation, which are liable to mislead the student. In defence of the method it may be said that the same result can be reached by adhering to the doctrine of evolution, but the scheme would necessarily be intricate and involved to such an extent as to be confusing to the average medical student. Besides, the terms of creation are used because they are more suggestive of the facts of anatomy than any terms that may be devised. Perhaps the most important testimony in favor of this method of teaching anatomy is that given by Professor Huxley, the greatest advocate of the theory of evolution. In one of his later lectures, describing the process of development of an ovum as the several stages are seen to succeed each other in symmetrical order under a powerful microscope, he is reported as saying:—PBE 158.2

“‘Strange possibilities lie dormant in that semifluid globe. Let a moderate supply of warmth reach its watery cradle, and the plastic matter undergoes changes so rapid, and yet so steady and purpose-like in their succession, that we can only compare them to those operated by a skilled operator on a formless lump of clay. We see, as it were, a skilled modeler shaping the plastic mass with a trowel; as if a delicate finger traced out the line to be occupied by the spinal column and molded the contour of the body, pinching up the head at one end and the tail at the other, and fashioning flank and limb into the salamandrine proportions in so artistic a way that, after watching the process hour by hour, one is almost involuntarily possessed by the notion that some more subtile aid to vision than an achromatic would show the hidden artist with his plan before him, striving with skilful manipulation to perfect his work.’PBE 159.1

“A very distinguished writer refers to this quotation as follows:—PBE 159.2

“‘The above are Huxley’s own words That is to say that the first biologist in Europe (according to Virchow), when he comes to describe the development of life, can only do so in terms of creation.’PBE 159.3

“With these explanatory remarks, I propose to develop the outlines of a course of study of anatomy based on the ‘Terms of Creation.’ If we approach the subject as inventors, and that is the true spirit in which we entered upon this study, our first inquiry would be as to the origin of the conception that man should be created. That is. What were the conditions existing which required the creation of man? We might, perhaps, arrive at a correct conclusion if we analyzed his existing organism, but, as in the Bible narrative, there is a statement of the immediate cause of his creation, and as this is the only record of the kind in human history, and answers our purpose, we will adopt it.PBE 159.4

“Referring then to the account of creation as given in Genesis, we learn that the earth had been prepared for living things, and in an orderly manner there had appeared grass, the herb, the fruit tree. living creatures in the waters, winged fowls, cattle and creeping things and beasts of the earth, and the Creator pronounced everything good. But now there seems to have been a pause in creation, and, as we follow the narrative, we learn it was discovered that there ‘was not a man to till the ground’ or ‘replenish the earth and subdue it’ or ‘have dominion’ over it. Here was a new incentive to creative energy, and apparently a more difficult task was never presented even to Omnipotence. The conclusion of the deliberations of the Council of Creation are given in the announcement, ‘Let Us make man in Our image, after Our likeness.’ This is the first recorded mention of man in the history of the earth. The decision is in the language of a council of architects, inventors, or creations. As students, we are at once interested in determining how this man was made in the image and likeness of the Creator. On examining the record, we learn only that the Creator ‘formed man of the dust of the ground, and breathed into his nostrils the breath of life.’ No details are given of the method of procedure in constructing the human body, and we are left to determine these facts by our knowledge of the laws governing the invention and construction of machinery, and an analytical and synthetical study of the completed organism as we have it before us. That is, we must place ourselves as nearly as possible in line with the logical thoughts of the Inventor, and thus have the machine develop in our own studies as it did in His.PBE 160.1

“In regard to the laws of invention, we have stated that the first conception in the inventor’s mind is function, the second structure. Having recognized the former, we are now to devise and create a structure adapted to perform that function. What rule shall be our guide!—Evidently the rules governing construction in all inventions. These rules may be stated as follows: Every inventor creates, first, the frame-work; second, the apparatus which operates it; third, the motor power or force which gives the apparatus energy or activity; fourth, the mechanism by which the life and the integrity of the organism is to be maintained; fifth, the organs by which the machine, as a whole, is to be reproduced.PBE 161.1

“Following the order of invention, we must determine what is the framework of the body, and begin construction with it. It is evident, on a general survey of the several tissues of the human organism, that the articulated bones make its framework or skeleton, for all the other tissues and organs are gathered about or are attached to it or concealed and protected within its recesses. We must, therefore, conclude that creative energy began the work of construction with the skeleton, and that this structure must be the first to receive our attention.PBE 161.2

“But how is he to construct the skeleton without a perfect knowledge of the materials of which it is composed? This inquiry leads the student at once to an exhaustive study of the intimate nature of bone, for a knowledge of these facts must precede actual constructive work. Turning to the articulated skeleton as an object-lesson to learn the principal functions of bones, he notices that: First, they must sustain great weight, and, second, they must act as levers in all of the movements of the body. As an architect, he knows that the structural peculiarities necessary to the performance of these functions are: (1) Hardness, to sustain weight; (2) lightness, to facilitate movement; (3) elasticity, to resist violence. Here are three nearly opposite qualities to be combined in one tissue, and his curiosity is intensely excited to discover the thoughts of the Divine Architect as He proceeds to solve the difficult problem. But we will not follow the student in his study of osteology, or the science of bone. We assume that every phase in its development from the selection of its constituent materials to their final organization must interest one who is seeking as an inventor to determine its adaptation to the purpose for which it is created. He can but marvel at the wisdom that takes certain salts of the earth and combines them with a peculiar kind of animal matter in such manner that these heterogeneous substances by some unknown and unknowable affinity create a new substance having the qualities of hardness, lightness, and elasticity; qualities essential to bone in the performance of its varied functions in the skeleton. Scarcely less wonderful to him is the development of bone from the osteal cell and the conversion of the body of the cell into a lakelet, through the medium of which the new bone is nourished by hydrostatic pressure. And as he follows the formation of bone to its completion, he discovers in the construction of its tissue the demonstration of two new and very important principles in physics. The first is that a hollow cylinder is stronger than a solid shaft of the same size. This principle applied in mechanics economizes the materials employed and renders the structure comparatively light, thus adding to facility of movement. The result is beautifully illustrated in the long bones or levers of the skeleton. The second principle is the Gothic arch, which gives the greatest power of sustaining weight with the least amount of material; the greatest elasticity with the highest degree of lightness.PBE 162.1

“Having completed a minute study of bone and obtained an accurate knowledge of its constituents, its methods of development, and the structural arrangements adapting it to its various purposes, the student is prepared to advance to the actual construction of bones, and of placing each in its proper position in the skeleton.PBE 163.1

“Surveying the skeleton as a whole, the question again arises, Where shall constructive work begin? In other words, Which series of bones was first created? His answer must be determined by recalling the principle of construction of all machinery, viz., the central or axial part must be made first. Applying this principle as he critically examines the articulated bones, his attention is at once arrested by the series which constitute the spinal column as not only central in location, but obviously the other bones are attached to it in such a manner as to prove that they depend upon it in the performance of their functions. He is warranted, therefore, in concluding that the spinal column must have been the part of the skeleton which first received the attention of the Creator.PBE 164.1

“But this conclusion does not solve the question as to the initial point where construction began, for the spinal column is constituted of many bones. He has decided as to the series of bones first constructed, but he has not fixed upon the individual bone in the series. In selecting that bone, he must again determine which is the most central and important as regards function. It must be noted that in this view a vertebra proper includes the corresponding ribs and their sternal attachments, as described by Professor Owen in his great work on ‘Vertebrates.’ In that system, ‘each complete segment, called “vertebra,” consists of a series of osseous pieces arranged according to a type or general plan, in which they form a hoop or arch above and another beneath a central piece; the upper hoop, encircling a segment of the nervous axis, is called the neural arch; the lower hoop encircling a part of the vascular system, is called the haemal arch; their common center is termed the centrum.’ A vertebra, thus defined, he calls a ‘type segment,’ and the skeleton of his ideal, or ‘archetype’ vertebrate, consists of a series of these perfectly-formed segments as we see them in the skeleton of a serpent.PBE 164.2

“As the student critically examines the different vertebrae to determine with which the Creator began construction, he is impressed with the important fact that, while the segments of the spinal column have a general resemblance to each other, as if constructed after one model, there are differences which become more and more marked when those of either extremity of the column are contrasted with those in the central or dorsal region. This region must be the point of departure in construction. On examining critically each vertebra to determine which is the ‘type segment,’ his selection falls upon the seventh dorsal, for all its-parts are more complete than any other, and its ribs are longer and more perfectly adapted to their functions. With the seventh dorsal, therefore, he concludes that construction must begin.PBE 165.1

“Taking this vertebra in hand to begin practical work, the student at once discovers that it is constituted of many individual parts, each adapted to its special function. Again, he must determine which part is the center or axis of the vertebra before he can positively decide where the construction work originally began, and hence where he is to commence his operations. Examining very carefully the several parts of a vertebra, and comparing it with the others in the series he notices that the body is the most important portion, for not only are the other parts arranged around and connected with it as a base of action, but it is the only constituent of a vertebra which is continuous throughout the entire spinal column. The body, therefore, or centrum, must have been first created. By this process of scientific inquiry and logical reasoning he reaches at last the initial point where the Creator actually began the work of constructing the human mechanism, viz., the centrum of the seventh dorsal vertebra.PBE 165.2

“Here, then, the student begins the actual study of what is, in a real sense,practical anatomy.’ The seventh dorsal vertebra is the point of departure from which he is to develop, in serial order, not only the skeleton, but the entire human organism. The science of anatomy, like kindred natural sciences, thus has its beginnings in a few simple principles or conditions, and out of them grow the complex forms which are so difficult to understand when studied independently and without a previous thorough knowledge of these fundamental facts.PBE 166.1

“As the student, now fully equipped for his task. begins constructive study, we may well regard him as Huxley’s ‘skilled operator on a formless lump of clay;’ ‘a skilled modeler shaping the plastic mass;’ ‘the hidden artist with his plan before him, striving with skilful manipulation to perfect his work.’ The plan before him is the articulated skeleton, and the materials are the individual bones; the former for synthetical study or the placing of each bone in its proper position, and the latter for analytical study, or the minute examination of its technical peculiarities. His method is still that of an inventor and creator, for he will learn the nature of the function before he begins structural work. Having found the initial point of construction of the mechanism which he is about to create, and being thoroughly familiar with the rules governing his art, our artist-student, our ‘skilled modeler,’ ‘with his plan before him,’ enters upon his task with enthusiasm, and pursues his studies with ever-increasing delight. We see him model with nicest skill the interior of the body of the seventh dorsal vertebra, filling it with Gothic arches that it may sustain great weight and still be very light. No sculptor’s chisel ever wrought in marble more artistic curves than those which he gives to the exterior covering With ‘delicate fingers’ he shapes the neural arch, ‘pinching up’ the terminal portions of the laminae to form the graceful spinous process. With mathematical exactness he cuts the articulating facets so as to secure a minimum of motion with a maximum of strength. For the haemal arch he forms the ribs and curves them so that they shall perform the twofold function of protecting the organs of the chest and aiding in respiration through their nicely-adjusted articulations with the body and lateral processes. He finishes the haemal arch with the costal cartilages and the sternum and, adjusting the several parts to each other, the seventh vertebra, the ‘type-segment,’ stands forth perfect in all its details, a beautiful specimen of high art. With its completion the student has acquired the key to a thorough knowledge of all the bones of the skeleton, for the remaining bones are but variations of the seventh dorsal, the ‘type-segment.’ And all of these variations from the seventh are simply designed to adapt other vertebra to new functions. Hence he proceeds with comparative ease in his constructive study of the spinal column below and above the seventh dorsal. As he descends, he modifies each vertebra according to its function, until he reaches the coccyx, where he preserves only a remnant of the body. As he ascends from the seventh dorsal, more remarkable changes take place, as in the atlas and axis, but most strikingly in the bones of the skull and face. But in these irregular and curiously-formed bones the ‘student-artist’ recognizes only variations of the ‘type-segment,’ adapting parts or the whole of the vertebra to new functions. Even in the bones of the upper and lower extremities he discovers two vertebrae which have undergone extreme variations owing to the peculiar functions they have to perform.PBE 166.2

“Thus in our scheme of study the seventh dorsal represents the ‘Vertebrate Archetype’ of Owen, which Holden says is ‘the grammar of all osteology.’ He adds, ‘Of this a student may rest assured, that however minutely he may have scrutinized the bones. he can not understand them unless he knows something of the vertebrate archetype; without this knowledge he is like one who speaks a language fluently, but is ignorant of its grammar.’ And we may add that he has acquired a chain of associated facts which will remain indelibly impressed upon his memory, and that will enable him to recall promptly the function and the structural peculiarities of every bone in all the emergencies of practise.PBE 168.1

“Having completed the skeleton or framework, our artist-student recognizes that it must be endowed with at least two forces to enable the coming man to perform the task of tilling the earth and subduing it. First, he must have the power of locomotion, or of moving from place to place, and, second, he must have the power of prehension, or of seizing and holding objects. In construction the student must have noticed that the bones were designed to move upon one another, and that those of the extremities take the form of levers. The question now before him is as to the kind of apparatus to be constructed to operate these levers, and how it is to be applied. Holding up before my class the seventh and sixth dorsal vertebrae in proper position, I asked, ‘How would you make these bones move on each other?’ A first-course student replied, ‘Attach a rubber strap to their spinous processes.’ He stated a principle and a fact; the principle was that the apparatus with which one bone is to be moved upon another must have the quality of contraction, and the fact was that such a strap as he suggested, though not made of rubber, was already attached to their spinous processes. The incident illustrates the readiness of the student, whose mind is trained to devise structures adapted to perform functions, to anticipate the very existence and nature of the tissues which he is about to study. It serves also to accentuate the proposition that I then made to the effect that, as these central dorsal bones were first constructed, according to our scheme of creation, we may logically conclude that to these bones were applied the first structures made to move the levers of the body. Here, then, at the seventh dorsal, we find the type muscle, and here we begin our constructive study of the muscular system.PBE 169.1

“Preparatory for constructive work, the student must now acquire, first, an accurate knowledge of the histological peculiarities of muscles and of their classification, and, second, he must practically learn the nature and classification of levers—two most interesting subjects to the inventor, and which, thoroughly understood, give to the surgeon great practical skill.PBE 170.1

“Assuming that he has acquired this knowledge, he begins the study of muscles in situ. He must reject altogether the method pursued in the text-books, which follows the order of dissections; for nothing could be more unscientific than to construct the muscles beginning with the most superficial layer and finishing with the deepest muscles. Now the order of creation must necessarily have been the very reverse of this. If we apply the muscles with our own fingers, as I propose, we must place the deepest layer first and the superficial layer last. This method has this obvious advantage, that the deepest muscles are usually simple and have a single action, while the superficial muscles are compound and complex in form and action.PBE 170.2

“It will be alleged that this method of study necessitates delaying dissections until the student has completed the review of the entire muscular system as given in the text-books. It is true that he would have to learn the muscles of a part, as the trunk or a limb, from his book before he attempted its dissection. And there is this advantage in such an order of studying, that his dissection will be much more carefully and intelligently made if he has already a correct knowledge of the parts he is now practically demonstrating.PBE 171.1

“Recurring now to the adaptation of muscles to the levers of the skeleton to give the latter functional activity, the question again arises in the mind of the artist-students as to the point where he is to begin. In other words, ‘Which muscle in the order of creation was first applied?’ Logically, the first bone created,—the seventh dorsal, according to our scheme,—would receive the first attention. Now the articulations of this bone show that it has a limited motion on the adjoining vertebrae, and to effect that motion the greatest leverage would be secured by attaching a muscle to the spinous processes of the two bones, as suggested by the student. He was thinking the thoughts of the Creator, for we find in the interspinales muscles the identical elastic cords that he the recognized as necessary for the performance of the first and simplest function of these bones. These simple structures, so small in the dorsal region, but so well developed in the cervical, may be taken as the first muscles applied.PBE 171.2

“Commencing then with the interspinalis muscle of the seventh dorsal vertebra, as the point of departure in the study of the muscular system, the student follows the line of constructive thought in the most natural and scientific manner to the final application of the last muscle to the terminal bones of the extremities. Throughout this entire study his dominant thought as an inventor is in each case, ‘What class of muscles must I select? and where shall I attach them to the bones to enable them to perform the functions for which they were severally created?’ Thus, as the skeleton developed from a single central thought, so the muscular system now grows under his plastic hand in symmetrical form from the little, delicate slip that he placed between the spinous processes of the seventh dorsal and its neighbor to the enormous, intricate, and complex erector spinae, multifidus and complexus, muscles of the back which students, following the old method of study, usually group very properly under the term ‘musculus perplexus.’ Having completed the muscles of the trunk, he proceeds to apply them to the great levers of the extremities. In this part of his study all his inventive faculties are inspired with the keenest insight by the revelation of the marvelous forms of adaptation of muscular force to effect the infinite variety of motions of these levers. And the one fact that perhaps will impress him most is this, that all these muscles, even to the terminal phalanges, have as the basis of their action the spinal column, and chiefly the central dorsal vertebra where he began the study of both the skeleton and the muscular system. This arrangement and action of the muscles will appear as he traces the peculiar relations of one muscle to another, beginning with the spinal column and terminating with the extreme bones of either limb. Though in the series there may be several muscles, each having its special function when acting alone, yet it is evident that they may all act together as a compound muscle, and perform a new and quite independent action. This is strikingly illustrated by Professor Owen in the figure of a man stooping under a heavy load, which rests upon his shoulders. The weight is sustained chiefly by the following muscles, viz., the erector spinae of the back, the glutei at the hips, the quadriceps extensors of the thigh, the gastrocnemii of the legs, and the short flexors of the feet. Here are ten separate and independent muscles, extending from the spine to the ends of the toes, now united in their action to perform one function.PBE 172.1

“In the construction of the human organism we have now completed the framework and the apparatus which is to operate it. But as yet we have only an inert and inanimate object, quite incapable of performing the duties for which it was created. Our next inquiry as inventors must be, ‘How shall these muscles be endowed with force and these dry bones be stimulated to activity?’ The result of creative thought and energy was the development of that marvelous and exquisitely beautiful mechanism the nervous system. Studying along the lines of creation, the dullest student becomes fascinated with the wonderful adaptation of means to an end which he discovers in every part of this system. but especially in the nerve-centers, where the power is generated which moves the muscles to action. As in the study of the skeleton and muscular system the student learned the intimate nature of bone and muscle before beginning construction, so now the histological peculiarities of the materials constituting the nerve tissue are thoroughly learned, and the special uses of each kind or form are fully understood. Then constructive work begins, and the point of departure is again the seventh dorsal, because here is found the type nerve-center of which all others are only variations to meet special functions. This one nerve-center, thoroughly analyzed and understood, is the key to a ready appreciation of the peculiarities of every other, as was a knowledge of the seventh dorsal vertebra a key to a quick understanding of the special features of every other bone of the skeleton. Even in the complicated and complex forms of nerve centers of the brain the student readily recognizes the special variations of the ‘type nerve-center’ made to meet new functions, and so appreciates the necessity of the changes that he forever retains them in his memory. Not less interesting when studied in order is the origin of nerves from the centers, the method of distribution through the medium of a plexus, their final termination in muscles and other tissues, and their relations, in their courses, to other tissues.PBE 173.1

“We have now reviewed the construction of three great systems of tissues,—the osseous for a framework of the mechanism, the muscular to operate it, and the nervous to give it energy. But it is apparent to us as inventors that this machine, being subject to ‘wear and tear,’ and hence to decay and death, must not only be supplied with the means of repairing waste, but of perpetuating itself when its life ends. These facts open new fields for constructive study, and the artist-student begins with renewed zeal to trace in his plan the origin and development of the digestive system, then its auxiliary, the circulatory system, and finally, the reproductive system.PBE 174.1

“We need not follow the student farther. He continues his study and construction along the lines of original thought, always first recognizing a function to be performed before he studies the apparatus designed to perform it. As he proceeds, all the details of the mechanism unfold in the logical order peculiar to the natural sciences, ‘pointing,’ says Holden, ‘to the one great Cause of all organization.’PBE 175.1

“A student who has in this manner thoroughly mastered the several systems of tissues theoretically finds their demonstration by dissection a constant source of delight. Every stroke of the scalpel is made with precision, and reveals a hidden thought of the Creator in new and living light, which engraves upon the memory of the dissector the details of function and structure so distinctly that, at all times and in all emergencies, this knowledge is immediately available. And I may add, as a final statement, that to the philosophical, devout, and creative mind, seeking knowledge along these lines of inquiry, the ecstatic remark of Galen is eminently true, “The study of anatomy is a perpetual hymn to the gods.’”PBE 175.2