i ARMY MEDICAL LIBRARY WASHINGTON Founded 1836 Section.. Number .J?-(P-.3..3..(sl. Fobm 113c, W. D., S. G. O. (Revised June 13, 1936) .1 THE ANATOMY OF THE BRAIN, WITH A GENERAL VIEW OF THE NERVOUS SYSTEM. / By J. G. SPURZHEIM, M. D. Of the Universities of Vienna and Paris; Licentiate of the Royal Col. of Phys. in London. TRANSLATED FROM THE UNPUBLISHED FRENCH MS. BY R. WIL- LIS, MEMBER OF THE ROYAL COLLEGE OF SURGEONS, LONDON. WITH AN APPENDIX, AND EIGHTEEN PLATES. FIRST AMERICAN EDITION, REVISED BT CHARLES H. STEDMAN, M. D. Physician and Surgeon to the United States Marine Hospital, Chelsea. •'Si;;- ' "^ ' BOSTON: MARSH, CAPEN & LYON. 183 4. Entered according to Act of Congress, in the year 1834,by Mahsh, Capen & Lyon, in the Clerk's Office of the District Court of the District of Mass. WL S 7 U'cx. c BOSTON: \ \ James B. Dow, Printer, > ( 122 Washington Street. ) CONTENTS. PAGE. Preface to the American Edition..............................v Preface to the English Edition.............................xiii Section I.—General Considerations........,....................9 Of the Existence of the Pulpy and Fibrous Substances.........10 Of the Structure of the Two Nervous Substances.,............11 Of the Use of the Pulpy Nervous Substance...................14 Of the Ori Jin of the Nervous System....... ...............17 Of the Mode of Formation of the Nervous System........ ---22 Of the General Form of the Nervous System..................24 Of the Structure and Use of Ganglions.......................25 Section II.—Division of the Masses composing the Nervous System...............................................29 Section III.—Of the Nervous Masses of Voluntary Motion, and of the External Senses...............-..................41 Of the Nervous Mass of the Vertebral Column.................54 General Considerations on the Spinal Cord of Man and Animals. 54 Particular Considerations in regard to the Spinal Cord..........64 Of the Pretended Cerebral Nerves, &c........................70 Of the Accessory Nerve.—Spinal, or Spinal Accessory of Wil- lis.—3d Branch of the 8th pair of J. Bell.-^Superior respi- ratory of C. Bell.......................................73 Of the Pneumogastric Nerve.—Par Vagum.—Middle Sympa- thetic.—Vocal.—Pulmonary 2d branch of the 8th pair......74 Of the Glossopharyngeal Nerve..............................75 Of the Hypoglossal Nerve.—9th pair of Willis.—Gustatorious of Winslow.—Lingualis of Vic d'A/.yr.—Sublingual........75 Of the Abductor Nerve of the Eye.—6th pair of Willis.—Ex- ternal Motor of Meckel.................................75 Of the Facial Nerve.—Portio Dura of the 7th pair.—Nervicus Communicans faciei of J. Bell...........................76 IV CONTENTS. Of the Motor Nerve of the Eye.—3d pair of Willis.—The Com- mon Motor of Meckel..................................76 Of the Nerve of the Superior Oblique Muscle of the Eye.—4th pair or Patheticus of Willis.—Trochlearis.—Internal Motor of Meckel.............................................77 Of the Trigeminal Nerve.—5th pair of Willis.—Trifacial of Meckel...............................................77 Of the Auditory Nerve.—Poitio Mollis of the 7th pair.—Acous- tic Nerve.............................................79 Of the Optic Nerve.—2d pair of Willis........................80 Of the Quadrigeminal Bodies................................84 Of the Olfactory Nerve.—1st pair of Willis.—Ethmoidal Nerve. .91 Section IV.—Of the Best Method of Dissecting the Brain........95 Section V.—Of the Cerebellum..............................105 Section VI.—Of the Brain..................................135 Decussation of the Anterior Pyramids.........................140 Two Portions of the Crura and Cerebral Masses..............145 Comparative Anatomy of the Brain..........................152 Structure of the Convolutions..............................155 Section VII.—Of the Commissures of the Nervous Apparatuses. .167 Section VIII—Of the Communications of the Nervous Appara- tuses ..........................,...,......... i go Section IX.—Of the Anatomico-Physiological Relations of the Nervous Apparatuses.................................\qq Explanation of the Plates and Figures.......................200 Appendix........................................... > ^ ggi On the Brain, as an Aggregation of Parts....................221 The Parts of the Human Brain in the ordinary State of Health are essentially the same, and only modified in Size and Quality............................................ 22« In certain Idiots, Individual Portions of the Brain are defective, or even wanting............................. gog The Brain of the Ourang-Outang does not contain all the Parts of the Human Brain.......................... oqo Some Remarks on Mr. Charles Bell's Animadversions on Phre- nol°^................................................236 PREFACE TO THE AMERICAN EDITION. In presenting to the public an American edition of Spurzheim's Anatomy of the Brain, the editor feels that the opportunity now offering should not be allowed to escape, without adding his feeble tes- timony to the facts herein advanced, — facts which have gone farther to establish, elucidate, and perfect the physiology of the brain, than any discoveries ev- er before made. What Harvey, J. Hunter, and Linnaeus, in their several researches into the animal kingdom, have effected, the same have Gall and Spurzheim accomplished ; — the establishment of a foundation, on which will rest all subsequent discov- eries in their respective branches of science. But, alas! all this good acquired' and bestowed, has not always met with that applause and cordiality of reception which was its due. Who does not know with what indifference and neglect the facts observed and proclaimed by the immortal Harvey, were treated — who lived to see scarcely a solitary convert to his opinions ? The facts and observations of Hunter and Jenner were subjected to nearly simi- Vi PREFACE. lar contumely and incredulity. So has it been with Gall, and his no less illustrious associate. It would have been astonishing, had not their labors likewise been held up to the world as profitless and vain. How, may it be asked, could Gall and Spurzheim expect to escape censure, with the fate of Galileo, Harvey, and other philosophers, before their eyes ? The history of science swells with the multiplied accounts of the persecution and neglect of its suc- cessful devotees ; so much so, that in fact, the value of a discovery or invention would seem to be in the ratio of the abuse and indignity heaped upon it. Though both Gall and Spurzheim lived through much reproach, yet long before death they enjoyed the bright satisfaction of witnessing the rapid march of their opinions. Concessions to the truth of their observations poured in upon them from all quarters ; slowly, indeed, but with a steady and increasing progress. France has honored Gall, as she should, with that generous regret she always bestows upon the remains of those who have honored her. Great Britain and New-England, who knew Spurzheim well, have striven to do justice to his character and remains, by wiping away the obloquy and reproach cast upon his successful labors, and by bestowing on him the highest and only honors the living can heap upon the dead. Already does Phrenology number among its advo- PREFACE. vn cates in Great Britain some of the most scientific men of that country; and its march has been such, that the Reviews and Magazines, once so bitterly opposed to ' German fancies,' to Spurzheim and his doctrines, have joined themselves to his friends, and heartily repent of their former inveterate hostility. Some injudicious, though warm and talented sup- porters of the new system of mental philosophy have chosen to elevate the admirable Gall at the expense of the character and invaluable services of Spurz- heim : but Time, who proves all things, will judge between these eminent co-workers in the cause of truth. Time will prove that the foundation of the science of Phrenology was laid by Gall ; but, that without the aid of Spurzheim, the superstructure had not been reared. As to the comparative merits of these two great men, it may be proper to subjoin the following ex- tract from the Edinburgh Phrenological Journal, No. 6, page 189-90: { As Newton was the first to establish on a firm and solid basis the connexion of physical with math- ematical science, so Gall has been the first to de- monstrate on proper principles a connexion between physical qualities and the manifestations of mind. La Place verified, illustrated and perfected the dis- coveries of Newton ; and Spurzheim has verified, il- lustrated, and brought to a state nearly as perfect, Vlll PREFACE. the discoveries of Gall.' Again, as to the respective value of their writings : — * When we enter upon the perusal of Gall, we feel as if we were in a country abounding with objects of the most striking sublimi- ty, and rich in all the dread magnificence of nature. We wander untired through the boundless variety, and we perceive in every new scene something to excite our wonder and admiration. In the works of Spurzheim, on the other hand, we feel as in a gar- den ; where all is regular and orderly; where all the different productions of nature are placed in an exact scientific arrangement; where we may study them leisurely and at our ease; and where we may see brought together, in a comparatively small space, the product of every zone and of every climate in the known world.' Again, in No. 9, page 107 : ' In his own [Gall's] science he never can have a rival......A man who is to be named only with the Harveys, and Galileos, and Newtons, has nothing to dread from any com- petitor ; and in his own department there never can be found any similis aut secundus. The proximos Mi honores have certainly been occupied by Dr. Spurzheim; and as Dr. Johnson has remarked of Milton in regard to epic poetry, so it may be said of Dr. S., that he is not the greatest of Phrenologists, only because he is not the first. His contributions to the science betoken powers of the very first or- PREFACE. IX der; and his services to Phrenology no possible cir- cumstance can ever make us forget or undervalue, nor will posterity ever forget or undervalue them.' It does not belong to us here, nor is there space to point out the particular share that Gall or Spurz- heim had in the anatomical portion of this work. The author has given Gall, as far as practical utility demanded, all the credit due him, and has taken no- thing upon himself that was not rightfully his own. No one will question the unparalleled skill, ease, and perspicuity with which Spurzheim laid open to his anatomical classes the heretofore hidden myste- ries of the brain. In Boston, where we had been accustomed to the ancient method of exposing, or rather keeping out of view the structure of the cere- bral masses, by slicing the brain, each demonstration of Spurzheim seemed to his attentive audience as a ray of light beaming through the mist, and dispers- ing the bewildering haze in which the subject had before been enveloped. We had heard, indeed, that something of the kind had been accomplished by this same Spurzheim in Europe; but the strength of our incredulity had not been put to the test. The presence of this genuine anatomist actually demon- strating the brain, and displaying its organization, had not hitherto been granted us. At length, how- ever, he came, and taught, until, with most, if not all his auditors, unbelief and prejudice began to van- 13 X PREFACE. ish by degrees, and the consciousness of truth to reign in their stead. No one, then present, can say in sincerity that he was not instructed ; but rather, with the exception perhaps of two or three, all will pronounce themselves, not only instructed, but con- verted. The proof of the extension of Spurzheim's views in this country, may be found in the sale of his works, and in the continued call for further editions. This edition of his Anatomy of the Brain may be considered somewhat in the light of a second Amer- ican edition; there having been 250 copies ordered by himself from England, which arrived after his death, all of which have been sold. Not only pro- fessional men and anatomists, are anxious to obtain the ' Anatomy of the Brain,' but the scientific lovers of truth not of the profession, likewise desire to ex- amine the validity of the facts embraced in the work. So far as this has been done, conviction as to the grand points, has followed. For my own part, be- ing so situated as to enjoy frequent opportunities for dissecting the brain, I have carefully investigated the cerebral masses according to this mode of exam- ination. By this method, (and there seems to be no other systematic course) the true structure of the brain, from its commencement in the medulla oblon- gata, to the,termination of its diverging fibres in the pulpy substance, and the union of its converging PREFACE. XI fibres, by which all parts are brought into perfect connexion, is discovered ; together with the rein- forcement of these fibres, and their successive addi- tions, by means of the gray substance distributed throughout all parts of the cerebrum and cerebellum. Thus the fact of the plurality of organs in the brain, is established, together with their constant inter- communication. If, with the knowledge of this important anatomi- cal disposition of the cerebral organs, we now con- nect the multiplied and multiplying facts derived from the examination of the exterior of the cranium, and also the observations made upon the intellectual and affective faculties of man, together with the state of the brain and mental manifestations in dis- ease of that organ, we cannot easily avoid the con- clusions arrived at by Gall and Spurzheim, that the faculties of the mind are innate, and that they pos- sess a habitation in the brain well characterized and defined. The share the editor has assumed in the republi- cation of this edition, is but small. It evidently ap- pears, from a careful perusal, that the translation and publication of the London edition was hurried ; for this reason, some passages, the true meaning of which was somewhat ambiguous, owing perhaps to the difficulty of translating literally, and at the same time correctly, from the French manuscript, have Xii PREFACE. been altered, and their phraseology adapted to the character of our own language. Several typographi- cal errors have likewise been corrected ; and a few almost unimportant notes added. Much more, unquestionably, could have been ef- fected by way of increasing the size of the book; but the editor has many doubts as to the real value which might result from such an undertaking. Pages after pages might have been filled with spec- ulations and unestablished opinions ; by which, how- ever, the real advancement of the knowledge of the anatomy of the brain would not have been effected. It has been preferred, therefore, to let the facts here displayed stand as they are, — in the simplicity and dignity with which they have been clothed by the immortal Spurzheim. C. H. S. U. S. Marine Hospital, ) Jan. 13,1834. $ PREFACE. The affective and intellectual faculties of man, both in their healthy and diseased condition, are un- questionably dependent on the body ; and, among the various branches of anthropology, anatomy is the basis of all the others. The organic apparatus- es, which are indispensable to the mental manifes- tations, consist of the brain, cerebellum, spinal cord, and the nerves of the external senses and voluntary motion. To make known the structure of these parts, is the special object of this volume. History proves that the structure and destination of the nerves were long unknown. Hippocrates and Aristotle, for instance, confounded, under the same general title, ligaments, tendons, nerves, and even blood-vessels. Hippocrates believed that the nerves terminated in muscles and bones, and pro- duced voluntary motion. Herophilus, who lived nearly three centuries before the commencement of the vulgar era, was the first who discovered the con- nexion of the nerves with the brain, and who looked on them as the instruments of sensation. Erasistra- XIV PREFACE. tus divided the nerves into those of sensation and those of motion ; the first he derived from the brain, the second from the membranes. Galen held that the nerves of sensation arose from the brain, and those of voluntary motion from the spinal cord. In the sixteenth and succeeding centuries, the brain and nerves were subjects of much research; but it is only in our own times that they have begun to be Understood, —that their true structure has been dis- covered, and that new ajid unthought-of functions have been proved to belong to them. The nervous beins the most delicate tissues of the body, necessarily required extremely careful and often-repeated examination to be understood ; and this they could not receive during those ages when prejudice opposed insurmountable obstacles to the dissection of dead bodies. It is therefore easy to conceive why such slow progress was made in the anatomical knowledge of the nervous system. Dr. Gall is the original author of a new physiolo- gical doctrine of the brain.* The discovery of the ground-work of this is all his own ; and he had even gone very far in rearing the superstructure before the year 1804, when I became his colleague. From this period we continued laboring in common until 1813, when our connexion ceased, and each began to pursue the subject for himself. The works which Dr. Gall has published in his own name, fix PREFACE. xv the extent of his phrenological knowledge. My ideas are developed in my own publications : histo- ry will assign to each of us his share in the works that have issued under our joint names. It was in the year 1800, that I attended for the first time the private course of lectures which Dr. Gall had been in the habit of delivering occasionally at his house for four years. At this time he spoke of the necessity of the brain to the manifestations of the mind, of the plurality of the mind's organs, and of the possibility of discovering the development of the brain by the configuration of the head. He pointed out several particular organs of different memories, and of several sentiments, but he had not yet begun to examine the structure of the brain.* Between 1800 and 1804, he modified his physiolo- gical ideas, and brought them to the state in which he professed them at the commencement of our travels.f Dr. Gall having met with a woman, fifty-four years of age, who from her infancy had labored un- der dropsy of the brain, and who, nevertheless, was as active and intelligent as the generality of females in her own-rank of life, and being convinced that the * Exposition de la Doctrine de M. Gall, par Froniep. 3me edit. 1802. ) Bischoff Exposition de la Doctrine de M. Gall, sur le Cerau et Ie Crane, Berlin, 1805 ; et Blcede, la Doctrine de Gall sur les Fonctions du Cerveau, Dresden, 1805. XVI PREFACE. brain was the indispensable organ of the soul, ex- pressed himself in terms similar to those which Tulpius had used before him, on observing a person afflicted with hydrocephalus, who exhibited good intellectual faculties, viz., the structure of the brain must be different from what it is commonly suppos- ed to be.* He now felt the necessity of. examining the mind's organ anatomically. As his medical practice occupied his time, he employed M. Niclas, a student, to dissect for him; but the spirit of this gentleman's researches was merely mechanical, as is allowed in our joint work, entitled ' Anatomie et Physiologie du Systeme nerveux en general, et du Cerveau en particulier.' f Having completed my studies in 1804, I became associated with Dr. Gall, and devoted myself espe- cially to anatomical inquiries. At this period, Dr. Gall, in the Anatomy, spoke of the decussation of the pyramidal bodies, of their passage through the pons Varolii, of eleven layers of longitudinal and transverse fibres in the pons, of the continuation of the optic nerve to the anterior pair of the quadri- geminal bodies, of the exterior bundles of the crura of the brain diverging beneath the optic nerves in the direction which Vieussens, Monro, Vicq d'Azyr, * Lancet, Vol. x. p. 244. t Preface to the first vol. p. 16. PREFACE. xvn and Reil * had followed, the first, by means of scrap- ing, the others, by cutting the substance of the brain. Dr. Gall showed, further, the continuation of the anterior commissure across the striated bodies ; he also spoke of the unfolding of the brain that hap- pens in hydrocephalus. The notion he had con- ceived of this, however, was not correct; for he thought that the convolutions resulted from the du- plicature of a membrane, believing that the cerebral crura entered the hemispheres on one side, expand- ed there, and then folded back on themselves by the juxtaposition of the convolutions. The true struc- ture of the convolutions, and their connexion with the rest of the cerebral mass, were not described until our joint Memoir was presented to the French Institute in 1808. The mechanical direction which the anatomical investigations had taken, did not appear to me satis- factory. Guiding myself in my inquiries by physio- logical views, always comparing structure with function, I discovered the law of the successive ad- ditions to the cerebral parts ; the divergence in every direction of the crural bundles towards the convolu- tions; the difference between the diverging fibres and those of union ; the generality of commissures ; the true connexion of the convolutions with the rest * Gren's Journal, 1795, i. p. 102. C XVJ1J PREFACE. of the cerebral mass, and the peculiar structure which admits of the convolutions being unfolded (nn event that occurs in hydrocephalus of the cavities,) whilst the mass lying at their bottoms, and belonging, for the most part, to the apparatus of union, or of the commissures, is pushed by the waters between the two layers composing them : lastly, I demonstrated the structure of the nervous mass of the spine ; and I flatter myself with having arrived at the best method of dissecting the brain, and exposing its parts. What is my object then in publishing this volume ? Our large work is too expensive for the generality of medical students; and, further, the method pur- sued in the discussions there, is only calculated for professed anatomists — whilst this book will be both less costly, and it will be adapted to the student as well as to the more advanced anatomist. Moreover, many new ideas, possessing a great share of interest, may now he added; for, since Dr. Gall and I first published, the study of the nervous system has en- gaged the especial attention of anatomists and phy- siologists. I have, myself, continued inquiring, and conceive that I have made several new discoveries. 1 have, however, copied some passages from the first volume of the large work already mentioned, and also given reduced drawings of several of its plates ; because I think I have acquired a right to this vol- ume, by its publication in our joint names, by my PREFACE. XIX discoveries, that form its principal object, and by all I did in furtherance of its publication. All the drawings were executed under my superintendence from anatomical preparations, made and determined on by me : the engraver worked by my directions ; no plate was sent to press without my approval: the descriptions of the plates, and anatomical details are mine; and I furnished the literary notices in regard to the nerves of the abdomen and thorax, to those of the spinal column, of the five senses, of the cerebel- lum, and of the brain. Whoever desires more copious historical details than this volume will be found to contain, I refer to our Memoir, addressed to the French Institute, and to the first volume of our great work, commenced in common, and continued by Dr. Gall singly, after the middle of the second volume. The influence our labors have had on the study of the nervous system is incontestable. To be con- vinced of this, it is enough to examine the state of knowledge in regard to the anatomy, physiology, and pathology of the brain and spinal marrow, when Dr. Gall and I developed our ideas on these matters, whether it was by teaching orally, by dissecting publicly, or by means of our writings. I confess there is great satisfaction in the consciousness of having contributed to the important reform that has been effected in regard to the nervous system. I am XX PREFACE. only sorry to observe, that many of our ideas are appropriated by the authors of recent publications, without any mention of the source whence they were derived, or of the individuals who first struck them out, or reduced them to a certainty by direct proofs. We are commonly enough mentioned, it is true, when such of our assertions as appear weak are the subjects of criticism ; but our names are kept in the back-ground, when points of importance become the matter of discussion. The public, for instance, by referring to the proper place, may judge whether Mr. J. Cloquet, in his 'Anatomy of Man,' has been suf- ficiently explicit in stating, that he has copied every one of the plates of the human brain contained in our large work. M. Serres, whose Memoir was deemed worthy of its prize by the Academy of Sci- ences of Paris, in the first volume of his work, uses our names no fewer than fifteen times, in connexion with a single idea, which he fancies he can refute ; and generally along with every fact that looks unfa- vorable to our opinion, he names us ; but he always forgets to cite us in relation to very many fundamen- tal conceptions which we had announced at the same time. They who have written to the following ef- fect : —«M. Serres has proved clearly the erroneous- ness of M. Gall's observations, and replaced them by others,' may undeceive themselves by attending to the remark I have just made. PREFACE. XXI M. Serrcs's publication forces me likewise to re- quest the reader to distinguish between a multitude of words and facts on the one hand, and the corolla- ries which result on the other. I agree with those who, in works of science, pay especial regard to truths demonstrable to others, to ideas available in practical life, and to clearness and simplicity of style. What purpose can the following passage serve, which occurs in the preliminary discourse of M. Serres, where, after having said that a monster may be a vegetation of its like, that it may have two heads, two tails, and six or eight extremities, but that it would remain strictly confined to the limits of its class, he exclaims : — ' This wonderful phenome- non is undoubtedly connected with the general harmo- ny of creation. What may be its cause ? We know it not, and in all likelihood we shall remain ignorant of it forever. It is one of the mysteries of creation, whose surface is meted by man, but whose depths are sounded and known to God alone.'1 * This phenomenon does not appear to me more extraordinary than that a kitten is not a puppy, or that a crab-tree does not produce pears. If the egg *' Cet etonnant phenomene est sans doute lie a l'harmonie generate de la creation. Quelle peut en etre la cause ? Nous l'ignorons et vraisemblablement nous l'ignorerous toujours. C'est un des mysteres de la creation, dont l'homme mesure la surface, mais dont Dieu seul sonde et connait la profondeur.' xxn PREFACE. of a bird in its ordinary state cannot produce a mam- miferous animal, why should the germ of this same egg, if it chance to be imperfectly developed, pro- duce a deformity like to one of the mammalia? Were the case thus, there would be some cause for amazement; but the universal fact of every animal producing its kind, is not, in my eyes, more astonish- ing than any other natural event. Further, the mass of facts cited, the number of dissections made, ought never to impose on us, nor be made a means for concealing the truth. Many of the anatomists who had lived before us, dissected some hundreds of brains, and they made a boast of their doings in this way ; but they did not perceive that which I pledge myself to have discovered before I had dissected a dozen ; for instance, the successive additions to the cerebral parts, and the two kinds of fibres, to wit, the diverging, and the fibres of union. Anatomists and physiologists had certainly looked upon heads without number; but, before Dr. Gall's appearance, had failed to discover the seat of a single cerebral organ. A solitary individual, a beggar, enabled him to detect the organ of self-esteem, pre- cisely as the fall of a single apple revealed the law of gravitation to Newton. Anatomists had seen many human brains without remarking any differ- ences among them; these, however, are, to say the least, as constant as similarities. The point that PREFACE. xxm essentially interests science is, the discovery of the truth, and this is then confirmed and established by all ulterior observations. The anatomy of the peculiar system necessary to the affective and intellectual manifestations, as well as anatomy in general, admits of consideration in several ways. First, it is simply descriptive, that is, physical ap- pearances alone are examined, such as the form, the size, and color of parts, the tissues which compose them, and their connexions. The nomenclature of the encephalon, of itself, suf- fices to show that such views had principally guided anatomists in their study of its structure. We still speak of the brain, of the cerebellum, of hemispheres, lobes, convolutions, and anfractuosities ; of a fornix, an infundibulum or funnel, of pisiform and striated, quadrigcminal and pyramidal, olivary and harrow- shaped bodies ; of a pineal gland, of a hippocainpus's foot, of a writing-pen, and many other parts,— some having very offensive names. Such views are easily conceived to be of little use in medicine. This is the reason why the generality of practitioners are satisfied with knowing the membranous envelopes of the encephalon, the large blood-vessels, the sinuses, the great masses of the brain and cerebellum, and the principal cavities. Of these views, however, I shall only take such notice as may be necessary to XXiv PREFACE. recognize the parts spoken of in my physiological and pathological considerations. M. Serres, in the first page of his work on the Anatomy of the Brain, says, « Up to the present time, (1824,) no one has dreamt of uniting into a body of doctrine all the knowledge acquired on the anatomy, the physiology and the pathology of the brain and nervous system. I shall attempt the survey of this vast subject.' * Dr. Gall's and my own works dis- prove this assertion, and they have only to be con- sulted, to prove that all our inquiries were directed into this very channel. We have constantly insisted on the importance of studying the nervous system under all relations at once. From the year 1817 to 1823, I regularly delivered ' a Course of Lectures on the Anatomy, Physiology, and Pathology of the Brain and External Senses,' twice a year. My course was always so announced, according to the custom in Paris, by public placards ; and my auditors must recollect that in my introductory discourse, I uni- formly insisted on the importance and necessity of studying these branches in connexion. From the above, it will be evident that M. Serres was mista- ken when he published himself 'the first to attempt *'Jusqu'ace jour (1824) personne n'a songe a reunir en corps de doctrine les connaissances acquises sur Panatomie, physiologie et la pathologie du systeme nerveux. Je vais essayer de parcourir ce vaste sujet.' PREFACE. xx r the survey of (essayer de parcourir) this vast subject.' Nevertheless, I most willingly allow that the princi- pal consideration is not the having been the first to examine the nervous system: the true merit of the inquirer consists in that which he has effected, that which he had discovered, and justice in these partic- ulars will, in time, be assuredly rendered to all. If, at any time, I seem more especially solicitous in showing the erroneousness of M. Serres's opinions, it is only because these have received the sanction of the French Institute, whose influence is great over the public mind. 2. Anatomy is physiological, when the structure of parts is studied in relation to their functions. This kind of anatomical knowledge is essential to practical medicine ; for, without it, the seat of de- ranged functions cannot be understood. For this reason, therefore, my anatomical details will always be given in harmony with the physiological ideas I entertain of the apparatus destined to the manifesta- tion of the affective and intellectual faculties. 3. Anatomy is peculiarly human, or, it compre- hends the other beings of creation. In the latter event, it is entitled comparative anatomy, and this is a field that possesses much interest for the anato- mist, physiologist, and practical physician ; I shall, therefore, enter upon it at frequent intervals, always D XXVI PREFACE. with the view of advancing the knowledge of the affective and intellectual nature of man. 4. Anatomy is entitled pathological, when it treats of the organic changes undergone by parts whether examined in connexion with, or independently of, their deranged functions. Inquiries in this direction belong less to the present volume, than to that I have published on Insanity. To it, therefore, I re- for the reader for details. The object of this compendium, then, is to present the principal views that may be taken of the physio- logical and comparative anatomy of the apparatus destined to the affective and intellectual manifesta- tions. It will be found divided into nine sections : in the first, I make some general reflections on the nervous system ; in the second, I speak of the divis- ion of the nervous apparatuses; in the third, I treat of the nerves of voluntary motion, and of the external senses; in the fourth, I discuss the best mode of examining the structure of the brain ; in the fifth, I describe the cerebellum particularly; in the sixth, I do the like in regard to the brain; in the seventh, I examine the commissures ; in the eighth, the communication of the nervous parts with each other; and in the ninth, I go into some anatomical points connected with physiology. The work will prove that I have adhered rather to philosophical views and principles, than to mere description of the PREFACE. xxv ii physical qualities belonging to individual masses, al- though this last be the most common, I might almost say the only, plan that is generally pursued. 1 have endeavored, in an especial manner, to class together the parts that constitute particular apparatuses, a practice, which to our predecessors was entirely un- known, as is abundantly evident from their nomen- clature of the brain and its parts. ANATOMY OF THE BRAIN. Section I. General Considerations. Nerves are whitish cords that pervade the bodies of the more perfect animals ; they are always made up of many filaments, each of which, however minute, is a tube that holds in its interior a peculiar pulpy substance, constituting one among the elements of organization. It is to a multitude of such tubular filaments, enveloped in a common sheath, that the term nervous cord, or nerve, is usually applied. These cords, as well as their component filaments, vary much in thickness and consistency. The last quality depends entirely on the texture of the envel- oping membrane. The nervous system comprises two distinct sub- stances ; the one gelatinous or pulpy, and usually of a grayish or brownish hue; the other fibrous, and of a more or less perfect white color. They are com- monly spoken of in books as the cineritious and medullary substances. 2 10 Of the Existence of the Pulpy and Fibrous Substances. Comparative anatomists are not agreed upon the constantly-conjoined existence of the two nervous substances. Some admit the presence of the white without that of the gray, especially in the spinal mass of many inferior animals, as reptiles and fishes. The nervous ganglions of the asterice are also said to contain no gray matter. The above observation is evidently made in con- sequence of more attention being given to the color, than to the essential nature of the pulpy substance. Pulpiness, not color, is its distinguishing character. There are animals whose humours, or, as was for- merly said, whose blood is white. The essential consideration is evidently, in this case, the existence, not the color, of the nutritious fluid. Should it not also be so in regard to the first or pulpy nervous sub- stance, which in the majority of animals is of an ash-gray or brown color? Undoubtedly it should, for it is well known to vary in complexion, not only in different species of animals, but even in individu- als of the same kind, according to their state of bodily health. The pulpy substance is commonly extremely pale in the brains of those who die of dropsy or pulmonary consumption.* * In the brain of a patient who died from anaemia supervening upon scurvy, the editor found the pulpy substance of the same shade of white as the fibrous possesses in the brain of those dying from acute disease; and this latter substance of a clearer white than is usually 11 The pulpy substance is found in the ganglions, and in the nervous masses of the head and spine of vertebral animals. In the mammiferous classes es- pecially, it occurs on the surface of all the convolu- tions of the brain and cerebellum, (a circumstance from which it derives its title, cortical,) in the masses called striated bodies, and optic thalami, in the interior of the crura of the brain, o the annular protuberance, of the dentated body, of the cerebel- lum, of the medulla oblongata, of the spinal cord through its entire length, and of all the ganglions of the body. It never of itself composes an isolated unit or whole ; it is always in connexion with the white or fibrous substance. Occasionally it lies in masses of varying magnitude ; and again it occurs in layers, or it runs along in slips, following the nerves in their course. Of the Structure of the two Nervous Substances. The first nervous substance is pulpy or gelatinous, and of a color varying from deep brown to a pale ash-gray or white. Its intimate structure is un- known. Ruysh, Vieussens, and almost all the con- temporaries of Haller, regarded it as a tissue of very fine blood-vessels. Ackevmaun of Heidelberg, and Walter of Berlin, in our own times, have held it to consist of an extremely attenuated prolongation of observed. It may be remarked in connexion with this subject, that this patient, during his latter days was of a very imbecile frame of mind, it being almost impossible to gather from him a correct history of his disease, or any profitable detail of its symptoms. 12 vessels, in the course of becoming still more minute, and ultimately composing the white or fibrous sub- stance. This is a very ancient idea: it may be traced as far back as the age of Praxagoras, who fancied that the nerves originated where the arteries ended. Albinus, and, at a later period, Scemmerring, have proved, by their injections, that besides very minute blood-vessels, there also exists a peculiar substance in the cineritious nervous mass. The first or pulpy substance, therefore, can only be said to have an immense quantity of blood-vessels distrib- uted through it. Vicq d'Azyr believed that he could trace fibres in the pulpy substance ; but what he saw was the white or truly fibrous substance, intermingled or uniting with the gray. The second, or white, nervous substance, is essen- tially fibrous, but it varies much in its degrees of consistency. Anatomists have differed extremely in their notions of its intimate structure. Some have maintained it to be solid, others have said that it was tubular. Some have found it, like the pulpy substance, composed of globules; and whilst some have held that it possessed no blood-vessels, others have argued for its entire composition of these. Lewenhceck, Vieussens, and Steno, believed that the white nervous substance was fibrous. This is the opinion which Dr. Gall and I have espoused. By scraping it in the brain, according to the direction of its fibres, these may be seen with the naked eye ; and if the scraping motion be oblique or transverse to their course, they will be seen to be drawn from 13 their natural direction, or to be torn. If the brain be boiled in oil, or macerated in diluted nitric or muriatic acid, or in vinegar, or alcohol, or if it be frozen, the fibrous structure of its white substance will be ren- dered extremely apparent. Some, however, say, that the fibrousness is then the consequence of a chemical change. As the same result, however, is constantly obtained, and as the fibres, whichever of the processes be employed, are regularly disposed in corresponding situations in a similar manner, the fibrous structure must of necessity be recognized as natural and inherent. A few authors have attributed the fibrous appear- ance of the white substance to the impressions of blood-vessels. This mistake may be detected at once, by comparing the course of the blood-vessels with that of the cerebral fibres. The reality of the fibrousness of the white sub- stance is further opposed, by saying that when the brain is cut, it does not appear, and that it is pro- duced by the force employed to tear the tough cere- bral masses asunder. To this I reply, that it is impossible, by means of a clean and smooth cut, to discover the structure of any extremely delicate and soft part whatsoever. Such a method is not even available in those cere- bral parts that are incontestably fibrous, as the pyra- midal bodies, the annular protuberance, the pedun- cles of the brain, &c. M. Bogros, of Paris, read a paper to the Academy of Sciences, on the 25th May, 1825, in which he maintained that every nervous fibre is perforated by 14 a canal, from its origin to its termination. The ac- curacy of this statement is far from being ascertained. The white nervous substance is generally called medullary. This name, however, ought to be dis- continued for two reasons : in the first place, the idea we form of marrow excludes the conception of fi- brousness ; and again, the functions of the nervous fibres are so superior to those of the marrow, that it is a pity to designate both by the same word. The name is an evidence of the error that was anciently committed, when every thing contained in an osseous cavity was considered as marrow. Of the Use of the Pulpy Nervous Substance. Different opinions have prevailed ever since the times of Vesalius and Piccoluomini, who directed the attention of anatomists in a particular manner to this subject, respecting the use and destination of the pulpy or gray substance. It has frequently been regarded as an organ of secretion, either of vital spir- its or of a nervous fluid. Unity of sentiment, it is probable, will not readily be obtained upon this par- ticular point: but seeing that the rudiments of each new shoot in trees are developed in a deposition of of mucilaginous-looking matter ; that the cartilages in animal bodies are successively liquid, gelatinous, and cartilaginous, and that several turn into firm bone; that anatomists, in many instances, have agreed in deriving the nerves from ganglions ; that the brain, too, is at first fluid, then gelatinous, and ultimately fibrous; in fine, that the pulpy nervous 15 substance is always found where the white fibres be- come more numerous ; that these are implanted, so to say, into it, and that a great quantity of blood-ves- sels are expanded on it; Dr. Gall and I have said, that it appears to us to be the source or nourisher of the white fibres. Let us, however, distinguish in this, as in every other place, between facts and infer- ences. Supposing that our ideas concerning the in- ference were really inexact, the peculiarities I have mentioned, and the essential importance of the pulpy substance to the nervous functions, must ever be admitted. Having said that a gray color is not unessential in the character of the pulpy substance, no objection to our notions of its uses can be derived from the fact of its supposed absence in the ganglions of the aste- rice. A gelatinous or pulpy matter does certainly enter into their constitution, and this is sufficient. The white substance is also said to be present in the brain and spinal cord before the pulpy or gray appears. If by this be understood the existence of the nervous masses that become white prior to an evident separation into two substances, and to the development of the convolutions, I agree; but if the rudiments of the brain, cerebellum, and spinal cord, be said to be white, and not gray, in the first instance, I positively deny the assertion. The ner- vous masses of the head and spine are pulpy or gela- tious, and decidedly grayish in color before they are white. Neither Dr. Gall nor I have ever thought of saying, that the portion of the completely-developed nervous system, which is pulpy and gray, and gives 16 birth to that which is white and fibrous. We did but intend to announce the fact of a gelatinous and grayish state of the brain preceding its fibrous and white condition, precisely as we should say of its en- tire mass, that it is liquid before it becomes gelatinous. Our idea of the formation of the nervous system, seems more especially plausible, asjt appears to be perfectly analogous to what takes place in the osseous system. Bone begins by being gelatinous ; it is then cartilaginous, and ultimately solid and earthy. I re- peat, however, that no one can be more impressed than myself with the difficulty of drawing general conclusions: I am, therefore, very far from being anxious to impose such as I do infer, upon others. I only insist on the necessity of exactness in regard to the facts related. Putting our theory of the forma- tion out of the question, entirely, Dr. Gall and I still assert our title to be considered as the first who dis- covered and made known the general relation that prevails in man and the mammalia, between the pulpy and fibrous substances of the brain and its several parts. Messrs. Foville and Pinel Grandchamp have of late inferred, from pathological observations, that the su- perficial cineritious substance of the brain presides over the intellectual functions, and its white and deep- seated gray mass over locomotion. I am disposed to set much store by pathological observations ; yet I do not see that we dare place un- limited confidence in them alone. Truth is, I con- ceive, universally harmonious ; it consequently can- not have been attained in any case until anatomy 17 and physiology and pathology accord exactly. Now, who will maintain that the locomotive powers of ani- mals are great in proportion as their brains contain more of the white nervous substance, and as the striated bodies and the supposed origins of the optic nerves (thalami) are large ? Or, who will say that the locomotive capacities of inferior tribes, in whose brains the gray substance predominates, are less re- markable than their intellectual endowments ? These positions are alike untenable. Dr. Gall and I suppose that each nervous apparatus is composed of two pe- culiar substances, the pulpy and the fibrous, and that both are necessary to produce an instrument adequate to the performance of a particular function. Of the Origin of the ISiervous System. The brain has very generally been regarded as the sole and common origin of every part of the nervous system. Even the old anatomists, who classed the brain with the viscera of the chest and belly, and treated of its structure in their chapter of Splanch- nology, mistook it, however strange the error may seem, for the source of all the nerves. In their eyes, the spinal cord was a prolongation of the cerebral mass, and the great sympathetic, and the nerves of the thorax and abdomen, were continuations of the encephalon and spinal cord. This erroneous view, as it was espoused, was especially defended, by ob- serving that the commands of the will issued from, and that all consciousness resided in, the brain. 3 18 These facts, however, in truth, prove no more than the communication of the nervous masses of the body with those of the head. The muscular fibres, we see, are excited by the nerves, but they are not, therefore, continuations of the nervous filaments. The notion, however, was so palpably erroneous, that anatomists were not long in calling its soundness in question, more especially in regard to the nerves of vegetative life. Wihslow,* for instance, separated the great sympathetic from the spinal cord and brain ; he even regarded the bundles, that run between its gang- lions or masses, as simple branches of communication; and went so far as to say, that all ganglions ought to be considered as peculiar origins of nerves, and, con- sequently, as so many little brains. Scemmerring likewise observes, that the sympa- thetic, having an independent existence, may rather be said to go to, than to come from, the spinal cord. He adds, that it never forms a trunk in any wise pro- portionate to the number and size of its communica- ting branches, and that it never loses itself among muscles, but follows the course of the blood-vessels.f Bichat has expressed his opinion in the most pos- itive manner upon the subject. < The ideas of anat- omists,' says net ' upon this important nerve, seem to me very little accordant with what nature proclaims to be just. All agree in representing it as a medulla- ry cord, extending from the head to the os sacrum, sending various branches, in its course, to the neck, the chest, and the abdomen ; having in short, a dis- * Anatomy. f Hirn und Nerven. % Sur la Vie et la Mort. 19 tribution analogous to the spinal nerve, from which, or from those of the neck, it is said by some to de- rive its origin. Whatever the name chosen to desig- nate it may chance to be, sympathetic, intercostal, or trisplanchnic, the mode of considering it will still be found to remain unchanged. ' This mode I regard as altogether erroneous. In fact, there exists no such nerve as these names are used to signify. That which is taken for a nerve is, in truth, but a suit of communications between dif- ferent nervous centres, situated at various distances from each other. ' These centres are the ganglions, scattered through the different regions of the body. They have all an independent and isolated action. Each is a partic- ular focus, sending a multitude of ramifications, to carry into the respective organs the irradiations of the centre whence they proceed. ' Whatanatomist,' he continues,' has not been struck by differences among the nerves ? Those of the brain arelarger, whiter, more dense, less numerous, and offer- ing few varieties ; whilst extreme tenuity, great num- ber, especially around the plexuses, grayish color, pe- culiar softness of tissue, frequently occurring varieties, are, on the other hand, the distinguishing characters of the nerves that issue from the ganglions. The only exception in either case are in the branches of com- munication between the cerebral nerves, and in a few of the twigs that unite the little nervous centres.' Bichat thought it essential to express these opinions in the descriptive anatomy. The view commonly giv- en is not calculated to convey an exact notion, either 20 of the nervous centres, or of the nerves that emanate from them. Comparative anatomy, and acephalic monstrosities among the mammalia and man, furnish incontrovert- ible proofs of the brain not being the origin of the nervous system at large. To compare the nervous systems of different tribes, is a task attended with much difficulty; but very many of the inferior ani- mals have nerves, although they have nothing that may be likened to a brain. Their nervous system, eonsequently, cannot have the origin commonly as- signed to it by authors. There are also many anatomical descriptions, to be found in books of acephalic monsters, among the more perfect animals, as well as the human kind, whose ner- vous system, notwithstanding the absence of brain, was quite perfect. That nerves may exist without a brain is therefore established as a truth beyond the sphere of doubt. Some writers, however, relying upon the authority of Morgagni, Haller, and Sandifort, have maintained that the brains of acephali exist in the first instance, but that dropsy of the cavities destroys the parts, which, at birth, are found wanting, along with the membranes and bony covering. But no one ever saw, an acephalic child whose brain and skull exhibited traces of such destruction. The integuments of the upper part of the head, where the destructive process is principally supposed, are commonly entire and healthy. Neither has any one, in these cases, discovered the cicatrices of ulcers, traces oferosion, or simply of absorption. The bones that compose the basis of the skull, when they exist 21 in acephali, are smooth and round at the edges. The whole inferior part of the encephalic mass, as well as the optic, auditory, olfactory, and other nerves, occa- sionally occur in a perfectly sound and natural state. How did these nerves and tender cerebral parts re- sist the action of a fluid that dissolved or caused the absorption of membranes and firm bone ? It must be allowed, then, that the brain may be prim- itively wanting, just as may the legs or arms, and that the nervous apparatus of the body does not pro- ceed from the brain. The first anatomical principle in regard to the nervous system therefore is, that it is not an unit, but consists of many essentially different parts, which have their own individual origins, and are mutual in communication. This principle Dr. Gall and I regard as essential to our physiological researches and deductions. No anatomist before us was ever so much interested in demonstrating its truth. We conceive that we have proved it satisfactorily in regard to the brain, as Bichat had done before us, to the nerves of the chest and belly. In addition to our first anatomical principle, there are three subjects that require to be taken into con- sideration separately ; these are, — 1st. The mode in which the individual parts of the nervous system are formed ; 2d. The order of development of these parts ; and, 3d. Their reciprocal relations. Dr. Gall and I, in our publications and anatomical demonstrations, have always spoken of the mode and order in which the cerebral parts are formed and de- 22 veloped; however, we never touched upon these points but in a general way, our attention being more especially given to the consideration of the plurality of the nervous apparatuses, of their communications, and of their mutual relations, the whole in harmony with our physiological and philosophical inquiries. Mr. Tiedemann, and, after him, Mr. Serres, have treated in a particular manner of the formation and succes- sive development of the several parts composing the nervous system. Of the Mode of Formation of the Nervous System. I have no intention of entering into any discussion upon Encephalogeny. My researches have not been of extent sufficient to qualify me either to admit or to reject the opinions promulgated by M. Serres up- on this subject. According to this gentleman, the spinal cord, the cerebellum, and the brain, are devel- oped from the circumference towards the centre, and not, ar anatomists had hitherto admitted, from the centre towards the circumference. He tells us, that there are many centres of formation, and that each apparatus is composed of several pieces, which are joined together, the extremities commencing, the middles terminating, the union. According to him, too, * the arteries exert a particular directing influence over the development of the nervous sys- tem. The spinal cord, he conceives to be formed un- *Tom. i. p. 568, et seq. 23 der the guidance of the intercostal, the cerebellum under that of the vertebral, and the brain under that of the carotid arteries. The vessels of the spinal cord, he says, appear first, and the outline of this part is soonest apparent. The common carotids appear next, and then the internal vessels of that name, which are distributed to the crura or legs of the brain, and to the bodies called quadrigeminal, and these are now evolved. The ver- tebral arteries reach the cranium last, and the cerebel- lum is the latest formed of all the nervous masses. ' The brain,' he states, ' is developed from before backwards, and the cerebellum from behind forwards, according to the direction of the blood-vessels. From this it comes that the callous body is evolved from behind forwards, as the arteria callosa gradually appears.' 1 intend in another place to cite M. Serres's notions upon the formation of some particular apparatuses. Here I only observe that he differs from M. Tiede- mann upon a very principal point; whilst M. Serres proclaims a successive development from the circum- ference towards the centre, M. Tiedemann publishes the reverse of this as the truth. I also confess that a great number of M. Serres's opinions appear to me little probable. Dr. Baron * lately showed the body of an hydrocephalic child to the Academy of Medi- cine in Paris, and proved that though the carotid arte- ries existed, the anterior cerebral lobes were wanting. M. Serres had made too hastily a contrary report * Bulletin des Sciences Medicales, Juin, 1825, p. 175. 24 upon this very case to the Philomathic Society the day before Dr. Baron made the dissection. In recognizing the whole importance of encephalo- geny, or the doctrine of cerebral formation, it still appears to me that its laws cannot be at variance with those that may be demonstrated in the brain, when it has arrived at maturity of growth. I farther opine, that conclusions drawn from the structure of the adult brain, are to be preferred to such as are founded on it in its embryotic state. I shall, in more places than one, have occasion to refer to this argu- ment, and especially when I come to treat of the an- terior commissure and callous body, to the end that I may rectify the erroneous opinions promulgated by M. Tiedemann. My great and sole object is to know the structure of the brain, such as it may be demonstrated in harmony writh physiology and pa- thology. Of the general Form of the Nervous System. The form of the nervous system, it may be con- ceived, varies according to the radiated, globular, or elongated configuration of the animal body, of which it is a constituent. It cannot be alike in the star-fish, worm, and caterpillar. (PL i. fig. 1.) Generally then, and even as its particular parts are concerned, the nervous system exhibits the greatest varieties of form. Its masses, too, occur aggregated, as in the skull, and spinal canal, or in the form of nerves properly so 25 called, or collected into knots differing in form, size, consistency and color, entitled ganglions. Nerves frequently emanate from distant and opposite sources to unite, anastomose, or twine together, and then to separate and run off in different directions. This is the particular arrangement to which the term plexus is applied. Ganglions and plexuses often form an intricate tissue together. Of the Structure and Use of Ganglions. Ganglions are bodies composed of the two nervous substances: the white or fibrous, and the gelatinous or pulpy, into which the first is plunged. The pulpy matter of the ganglions is commonly of a gray color^ of different degrees of intensity ; sometimes, how- ever, it has a yellowish, a reddish, or a whitish cast: it is easily distinguishable from the nervous filaments which it surrounds. The fibres of the white sub- stance, the second element of the ganglions, anasto- mose repeatedly; they also cross each other frequently; sometimes in every direction, or in their course par- allel with that of the nerve upon which the ganglion is formed. Ganglions of this last kind are commonly oval shaped, but those in which several nerves meet and inosculate, have for the most part very irregular forms. Anatomists have always entertained very differ- ent opinions upon the uses of the ganglions. Some, with Willis, have ascribed to them the secretion of what they style vital spirits ; others, with Yieussens 4 26 conceive them destined to separate and to strengthen the nervous fibres : many of the moderns again, Bichat, Reil, and others, think with Johnstone, that they serve to isolate from the influence of the brain the parts which receive their nerves from them. The latter authors divide the nervous systems into two parts, a cerebral and a ganglionary. The theory of the vital spirits is now forgotten. The ganglions are also proved to do more than merely separate or direct the nervous filaments,asMeckel the elder, Zinn, Scarpa, and others, have supposed. ' A glance,' says Bichat,* 'enables us to discover the greatest differences among them, (the ganglions.) There is evidently as great a distinction between the ganglions and the nerves that issue from them, as there is between the cerebral nerves and the brain it- self. There is difference of consistency and other outward qualities, and there is difference of properties. Were the nerves that come from the spinal cord merely unravelled in their passage through the gang- lions, this would be but a difference of form, and not of nature, and their properties, therefore, would re- main the same. Why has not nature placed gang- lions on the nerves of the limbs, as on those of inter- nal parts ? If there be only a resolution of nerves into finer filaments in ganglions, why is there no con- stant proportion between the fibres that enter on one side, and those that issue from the other ? Did the nerve that penetrates the superior cervical ganglion from above expand in its interior, and having reuni- *Anatomie Generate, T. 1. 27 ted its filaments form the cord that issues from below, it ought evidently to be of precisely the same size at its exit as at its entrance. Such a relation, indeed, between the nerves of the opposite extremities of ganglions, ought to be quite general. But a very cursory examination shows that a contrary disposition almost invariably obtains. The size of the ganglions should be relative to that of the nerves, whose ex- panded fibres are said to compose them. Why then are the intercostal ganglions so small, and the trunks which unite, or rather, to use the common phrase, originate, and then leave them, so large ? And why, on the contrary, is the superior cervical ganglion so voluminous, and its nervous branches so minute ? How can the frequent interruption among the gang- lions in the human kind, which in a host of animals are quite regular, be explained, if the nervous fila- ments which enter be continuous with those which issue from them ? How comes it that the ganglions and their nerves bear no exact proportion to the cerebral nerves, if the latter give them birth or ex- pand in them ? Why, in fine, has not the pain, that is transmitted by both kinds of nerves, the same char- acter ?' Scemmerring has made reflections very sim- ilar to these of Bichat. Notwithstanding all this, the opinion in regard to the use of the ganglions, which Johnstone, Bichat, and Reil entertained, and which others have adopted from them, is by no means exact. They do not in- terrupt the reciprocal influence of the brain and nerves of the spinal cord, nor of the brain and viscera of the chest and belly, either in the healthy or patho- 28 logical state of the body. They most certainly do not prevent impressions made on parts supplied with nerves from them, or diseased sensations of the vis- cera from being felt. On the contrary, the ganglions would appear essential to the structure of the nerves of sensation. They, however, abstract the parts they furnish with nervous energy, from the influence of the will. They also originate nervous fibres ; and serve, farther, as points of communication between different nerves. Lastly, as the existence of a ner- vous fluid is not impossible, nay, as in all likelihood such a fluid does exist, the ganglions may probably aid in its secretion or evolution, and modify its cir- culation or distribution. 29 Section II. Division of the Masses composing the Nervous System. We have already seen, among the general considera- tions, that the nervous system is not a simple unit, but an aggregation of parts, that originate and may exist separately, but which are in intimate communi- cation, as was required on account of the influence their functions mutually exert. The functions of the abdominal viscera, for instance, act upon those of the brain, and those of the brain influence digestion, cir- culation, the secretion of bile, &c. The nervous system, therefore, cannot be compared to a net, as is sometimes done, if, by this, similarity of nature in its constituent parts be implied. On the contrary, as differences are evident, divisions become indis- pensable. But the task of determining the instruments spe- cially dedicated to particular functions, is one of great difficulty. The ordinary division of the ner- vous masses is indisputably defective. A true one can only rest on the nature of the functions performed. These functions are naturally separated into two grand classes; vegetative, or organic functions, and phrenic, or functions taking place with conscious- ness. The nervous masses belonging to the first of these are, in common language, the great sympa- 30 thetic nerve, and the ganglions and plexuses of the thorax and abdomen. Bichat has divided them into a multitude of apparatuses, individually neces- sary to the offices of the particular viscera. This division is, in my apprehension, founded in nature. I regard the nervous masses of vegetative life as inde- pendent of those of phrenic life, in as far as their existence is concerned. I also incline to admit as many different kinds of nerves as different vegetative functions; I farther recognize their communications among themselves, and with the masses of the phrenic functions. The nervous masses of vegetative life are very simple in the lower tribes of beings ; they are more numerous as we mount in the scale, and as the func- tions of vegetative life become complicated. Their general arrangement, as was to be expected, varies according to the form and disposition of the viscera in species and individuals. If visceral functions, lo- comotion, and manifestations of sensibility be united, it is also conceivable that to separate the peculiar nerves of these dissimilar operations from each other, would be next to impossible. This consideration shows why some anatomists have compared the nerves of the caterpillar and worm to the great sym- pathetic ; whilst others have likened them to the in- tervertebral ganglions, or to the spinal cord itself. In the vertebral classes of animals, and especially in the mammalia, the nervous masses are distinctly separated, first, into these of vegetative life, and, second, into those of phrenic functions. Each of these may farther be subdivided into two parts ; the 31 first into nerves of viscera, or. as M. de Blainville* expresses himself, into a visceral portion, and into nerves of communication; that is, an apparatus which establishes sympathy among the visceral nerves, and between these and the nervous masses of the external senses, and of the affective and intel- lectual functions. The second, or nervous masses of phrenic life, again, are commonly divided into the brain, properly so called, the cerebellum, medulla oblongata, and spinal cord, together with the nerves of these four parts. M. de Blainville ranges the nervous masses of phrenic life under two titles: the one he styles Cen- tral, the other Ganglionary. ' The first, or central,' says he,f 'is susceptible of three degrees of develop- ment ; is always situated above the intestinal canal, begins with the oesophagus or pharynx, and is pro- longed, more or less backwardly, so as to correspond to a greater or smaller number of rings of the body when they exist. 1 The second, or ganglionary, consists of a very variable number of pairs of ganglions, disposed in a slightly different manner on each side of the first. ' The central portion is always composed of two similar halves, situated, the one to the right, the other to the left, and more or less intimately united, or drawn together by means of the peculiar appara- tus, styled commissure. It is divided into two rigor- * Bulletin des Sciences par la Societe Philomatique de Paris, 1821, Mars et Avril. f Op. cit. p. 44. 32 ously similar portions : a vertebral and a cephalic, in- cluded, as their titles imply, the one in the vertebral canal, the other in the cranium. Both contain gray and white substance, and longitudinal and transverse commissures. ' The cephalic portion consists, 1st, of an inferior bundle called pyramidal, which passes under the an- nular protuberance, continues long distinct from the cerebral peduncles, and runs to terminate in the an- terior, or olfactory lobe, of the brain. 2d. Of a su- perior bundle, which continues, in the first place, under the name of prolongation of the quadrigeminal bodies, to the cerebellum, and, running on the outer sides of the internal geniculated bodies, is lost on the hemispheres; and, in the second place, of a deep bundle, which may be followed to the mammillary bodies, and from thence into the optic thalami. The bundles named peduncles of the pineal gland, which are expended on the optic thalamus, are also to be regarded as belonging to this cephalic portion.' The same author subdivides his second or gang- lionary portion into ganglions without, and ganglions with, external apparatus. Among the former he reckons the olfactory masses, the hemispheres prop- erly so called, the quadrigeminal bodies, and the cerebellum. The olfactory nerve, according to him, is a cerebral mass, in which his inferior central bun- dle terminates. The hemispheres, he conceives, form another ganglion, having no external apparatus! but one transverse, (the callous body,) and two lon- gitudinal commissures (the peduncles of the brain and the fornix.) It is to this ganglion that the con- 33 volutions belong. He farther regards the striated bodies as appertaining to the convolutions, but re- marks that, for certain, their fibres do not originate there to go to the hemispheres. The quadrigeminal bodies are the third, and the cerebellum the fourth ganglion, without external apparatus. The title, visceral part of the nervous system, ap- pears to mc well chosen, but I do not think that the division into central and ganglionary parts, or the other subdivisions proposed, deserve the same ap- proval. In the first place, I cannot see that they are based on anatomical observation ; I do not believe, for in- stance, that M. de Blainville can demonstrate the continuation of the inferior bundle, or pyramidal body, into the olfactory nerve, nor that he can trace what he calls the deep bundle (faisceau profond) of his central portion into the mammillary bodies. Neither do I think that his divisions and subdivisions of the nervous mass pertaining to phrenic life, are consistent with physiological facts; but this in ana- tomical classification is quite essential: it is even acknowledged by M. de Blainville himself as its ba- sis. ' We ought,' says he,* ' to consider the ner- vous system as subdivided into as many parts as there are grand functions performed by the animal body.' According to the ideas of M. Desmouhns, the parts which constitute the complete cerebro-spinal system of mammalia, are — 1st, the spinal cord ; 2d, * Op. cit. p. 40. 5 34 the cerebellum, which is itself composed of three parts ; 3d, the optic lobes, or quadrigeminal bodies ; 4th, the lobes of the brain ; 5th, the olfactory lobes. These five parts are admitted by M. Desmoulins not to be always complete in the other classes of verte- bral animals, and also to be wanting, individually, without detriment to the rest. The sturgeon, lam- prey, frog, and some other creatures, have, he says, no cerebellum ; the skate and shark no cerebral lobes; many bony fishes no olfactory lobes; in short, he concludes, that generally speaking, the no- tion concerning the unity of the nervous system is a chimera. In opposition to M. Desmoulins's views, Dr. Bailly has maintained that every vertebra, or every seg- ment, through the whole length of the animal body, contains the same nervous elements; that belonging to each of the vertebrae of the head and spine, there are nerves of sensation, of motion, of digestion, and of an intellectual system, charged with the task of appreciating the impressions communicated by the others, and of producing determinations. In my apprehension, the cerebro-spinal system is not a simple unit, but a compound of many distinct apparatuses, each of which has particular functions, which, being taken together, constitute phrenic life. The several instruments are formed after a general plan, but the physical qualities, as the density, form, size, and color, of all, individually, differ not only in the classes and in the species, but also in the members composing each kind ; the number of par- ticular organs is likewise greater or smaller in the 35 classes and species, according to the amount of the primary functions or faculties ; lastly, each of the apparatuses is simple, or is compound. No one, however, can be said to be perfectly sim- ple ; each is, at least, double, or one of a pair. The organs of motion and of touch are evidently multiplied. It is essential in dividing and subdividing the parts of which the cerebro-spinal system is composed, to keep in harmony with physiology and pathology, and to distinguish between what is common to all, and what is peculiar to each of them. The first grand division must embrace the instru- ments of motion, and of the five external senses ; the second comprise the organs of the affective and intellectual functions. I think they are wrong who confound the spinal cord with the cerebral masses, and designate both by a common title, such as encephalon or brain. It is long since Dr. Gall and I pointed out this error, but it is still very generally sanctioned, by the French Academy of Sciences, for instance, so late as 1820, its prize having been accorded to the me- moir of M. Serres under the following title.—■'Conner une description comparee du cerveau dans les quatre classes des animaux vertebres, et particulierement dans ceux des reptiles et des poissons, cherchant a determiner I'analogie des differentes parties de cet organe, ou marquant soigneusement les changes des formes et des proportions eprouvees, et suivant aussi profondement que possible les racines des nerfs ce- rebreaux.' Here evidently the brain and its nerves only are spoken of. M. Serres, however, deemed it 36 proper to consider the nervous mass of the spine as well as that of the cranium, and he has designated these two systems by the same name, without any objection being made by the Academy to this ar- rangement. Let us turn to the facts that prove the brain and the spinal cord to be perfectly distinct and inde- pendent of each other. These facts are anatomical, physiological, and pathological. I here assume as an established point, that the functions of the spinal cord differ entirely from those of the brain. The development and demonstration of this truth belong to physiology. I have, accordingly, examined it particularly in my work on Phrenology. Physiolo- gical experiments and pathological facts tend equally to show that the brain and spinal cord are masses possessed of distinct functions that cannot be con- founded. This volume being destined solely to the discussion of anatomical views, I shall, at present, confine myself to such evidence as anatomy affords of the mutual independence of each of the nervous masses mentioned. And first — all that has been said, in a general way, upon the origin of the nerves, and their exist- ence, independently of the brain, applies particularly in the case of the spinal cord. The spinal cord sometimes exists in part, sometimes entirely, when the brain is altogether wanting. If, to this, it be ob- jected that the brain had been removed by absorp- tion, the answer I have given to the same proposition, in reference to the nerves in general, must be re- peated here. There is, also, one, and but one, case 37 on record, in which the brain existed, without the spinal cord.* It occurred in a child whose head or heads are preserved in the Hunterian Museum, in London; this child was born with one skull placed vertically upon another. Each of these contained a brain invested with its usual membranes ; the dura mater of each brain adhered closely to that of the other, and both were supplied by blood-vessels issuing from common trunks. Parts, consequently, as the brain and spinal cord that exist, or not, inde- pendently of each other, cannot constitute one and the same apparatus. 2. The nervous masses of the spinal canal and cranium bear no regular proportion to each other. Man, with his voluminous brain, has a smaller spinal cord than the ox or horse, whose brain is so much less. Bartholin in former times, and Soemmerring in our own days, made this remark, nevertheless, they both continued to speak of the spinal cord as a pro- cess or continuation of the brain. 3. The spinal cord is well known not to decrease in size as it descends in the vertebral canal, and as it sends off nerves. Its volume is even augmented, where its nerves are largest and most numerous ; this is obvious, especially towards its sacral end, as may be seen by turning to PL i. fig. 2, where this part of the spinal cord of a fowl is represented ; and vet the spinal cord is commonly considered as a pro- longation of the white substance of the brain and cerebellum ! *SeePhiloSoPh. Trans, for 1790, March 25th, and for 1798, Dec. 13th. 38 4. The direction of its nerves, especially in the mammalia, proves to a certainty, that the spinal cord is not a continuation of the nervous mass of the cra- nium. Every pair of spinal nerves is made up by several bundles: (PI. i. fig. 3 ; a part of a spinal cord of a calf;) some of these issue from below, and run upward; others come from above, and proceed downward and outward. Now it would be absurd to suppose that these bundles were continued, or de- rived either from the lower or upper extremity of the spinal cord. They undoubtedly originate at the place whence they issue individually. In regard to the fifth, sixth, seventh, and other pairs of nerves, styled cerebral (PL vi. fig. 1,) their direc- tion also shows that they do not come either from the brain or cerebellum. Santorini, when speaking of the course of the fifth pair, remarks, that after descending from the brain, it turns back and runs up- wards ; and he adds — ' if it do not probably come from below, entirely like the accessory nerve.' The proofs, confirmatory of the mutual independ- ence of the spinal cord and hemispheres of the brain and cerebellum, serve also to demonstrate the propri- ety of separating the nerves, styled cerebral, from the brain itself. The evidence in this, as in the other case, is anatomical, physiological, and pathological. For the reasons already given, I here rest on anatom- ical testimony alone ; for information on the others, I refer to my physiological and pathological treatises.* To proceed, then, we see monsters, occasionally, * Phrenology; or, the Doctrine of the Mind; Lond. 1825. Obser- vations on Insanity; Lond. 1816. 39 born without any of the proper cerebral masses, but with olfactory, optic, and acoustic nerves, either sev- erally or altogether perfect; and on the contrary, these nerves individually, or generally, have been found in a state of atrophy, whilst the brain v/as sound and well developed in all its parts. There is no proportion, whatever, between the cranial nerves and the true cerebral mass. Many animals have them much larger in proportion to their brain than man. I repeat, therefore, that I divide and subdivide the nervous masses according to their offices : first, into nerves of vegetative functions ; secondly of external sense, and locomotion ; lastly of affective and intel- tellectual operations: these last inhere in parts, which I style truly cerebral, superadded to the nerves of the senses. We shall, afterwards, see that the masses belong- ing to the last named class of functions require sub- dividing into instruments of particular functions, af- ter the manner of the external senses. This principle of the plurality of the nervous appa- ratuses is the basis of these anatomical considerations, and is indispensable to the physiological researches in which Dr. Gall and I have so long been engaged. It has been, and is still, contested, and at the same time it is brought forward as new. A reference, however, to the date and matter of our publications, will assign it to those who can claim it by right. The general idea of a plurality of organs, indeed, must be allowed to be very ancient, and not the dis- covery of any modern author; before Dr. Gall ap- 40 peared, however, none of the cerebral functions had been specified, and before our combined investigations , were made public, the structure of no special appara- tus had been demonstrated ; for the parts of the en- cephalon that bear distinguishing titles, do not, by any means, constitute particular organs. The spe- cial determination, as well anatomical as physiologi- cal, consequently, belongs to Dr. Gall and myself. 41 Section III. Of the Nervous Masses of Voluntary Motion and of the External Senses. These masses include the spinal cord, with its nerves, and the nerves of the head, distinguished by the title, cerebral nerves. They may, therefore, be divided and spoken of as spinal or vertebral, and as cranial. The former, principally contained in the canal of the vertebral column, are more considerable in size, and are entirely destined to the functions of feeling and voluntary motion ; the latter are less voluminous, but besides nerves of voluntary motion and of feeling, they include nerves of taste, hearing, sight, and smell. Anatomists have, at all times, separated the nerves of four of the senses, to wit — smell, taste, sight, and hearing, from those appropriated to feeling; they have also regarded the third, fourth, and sixth pairs of nerves as especially destined to motion ; but they have confounded all the other trunks of the medulla oblongata and spinal cord, and supposed the whole to pertain to feeling. It is long since I maintained the necessity of sub- dividing these nerves, and of admitting separate fibres for the functions of touch and of motion. My opinion was founded on facts, and anatomical, physiological, and pathological reasonings. It was long ago remark- ed that feeling and voluntary motion were not always 6 42 impaired or annihilated simultaneously; sometimes the one, sometimes the other of these functions was seen to be totally lost, whilst the other remained un- impaired. The conclusion then followed, and it had already been seized by Erasistratus of Alexandria, and that there were nerves of motion, and nerves of feeling. Pathological facts, therefore, first fixed the attention of physicians on this point, as they also gave the first idea of a decussation of nervous fibres in the brain, and of the peculiar structure of the convo- lutions. To the above some have replied that the admission of two sorts of nerves to explain the isolated lesion, whether of voluntary motion or of feeling, was unne- cessary : the loss of motion, they say, is consequent on a minor degree of cerebral affection, the destruc- tion of feeling on disease of a graver and more exten- sive description. This objection is purely speculative, and totally unsupported by experience. To make it even plau- sible, it should surely be capable of standing the test of physiological proofs in the healthy state ; that is to say, sensibility and volition should be shown to be mere degrees of the same power, volition being the lower of the two : but observation is very far from confirming such an opinion. Physiology, and analogy, in reference to the other senses, appear to determine feeling as a function en- tirely distinct from voluntary motion, and to prove each of these functions as manifested by the medium of a special organ or nerve. The functions of touch are active and passive, like those of the other exter- 43 nal senses. The muscles being called into action, would the internal faculties employ any of the senses to take cognizance of impressions from without ? They aid touch in feeling, as they assist sight in looking, hearing in listening, and the olfactory nerves in smelling. The nerves of voluntary motion, i. e., of its organs, the muscles, cannot propagate impres- sions of touch, nor the nerves of the skin those of motion. The impressions propagated by the nerves of motion come from within, as those transmitted by the nerves of feeling are derived from without. The muscles, alone, produce sensations of fatigue or weari- ness, and these have no relation to the nerves of feel- ing ; we may be excessively fatigued, and, at the same time, have the sense of touch extremely vigorous. Physiological and pathological facts being striking- ly and universally favorable to the idea of distinct nerves of feeling and motion, and four of the senses being evidently provided with peculiar nervous appa- ratuses, I have always maintained the probability of the same law obtaining, in regard to the fifth, and even invited anatomists to use their endeavors to verify the point, to demonstrate the muscular as dis- tinct from the cuticular nerves. To the above notion, it has been objected, that the nerves of feeling and of motion issue together from the spinal cord, and as a consequence of this, that the nature of every fibre, of the same pair, must be es- sentially the same. To this I always answered that the objection is neither valid on the strength of the fact, nor on that of the inference from it. For the spinal pairs are composed of two roots, the one dor- 44 sal, the other abdominal; and further, each root is, itself, composed of many bundles. I also stated that this structure was less conspicuous in the filth cranial nerve than in the spinal pairs ; but that, nev- ertheless, the difference of its bundles, and their dis- similar functions, were recognized. One, all allow, is appropriated to taste, whilst the rest belong to sen- sation in general. In conformity with the above view, the glossopharyngeal has always appeared to me destined to the third sort of the lingual functions, that is, to general feeling.* The above ideas were published in my English work, 'The Physiognomical System,'f in 1815; and in 1818, in my French book, entitled, ' Phrenologie.'J In all the courses of lectures I have delivered since these works issued from the press, I have broached similar ideas, and encouraged those of my auditors, whom opportunity favored, to enter on the inquiry, and to endeavor to trace the nervous fibres from their peripheral expansions to their origin in the spinal cord. The subject has, indeed, been advanced by the labors of Messrs. C. Bell and Magendie. Mr. Bell has recognized a difference between the nerves of sensation in general and those of respiration.^ He admits, in the first instance, that every apparatus performing a single function, is provided with but * For the more important synonyms of the cerebral nerves, so called, see Chapter II. ] First and second edition, p. 23. $ Op. cit. p. 236. § On the nerves; giving an Account of some Experiments on their Structure and Functions. Read before the Royal Society of London, July 12,1820. J ' 45 one nerve ; that parts which receive two nerves, whose origins are different, perform two functions ; and that organs whose nerves are derived from sev- eral sources, effect various, and not merely stronger, functions of one specific kind. He regards as respi- ratory nerves the pneumogastric, with its vocal branch ; the glossopharyngeal; the accessory of Willis ;* the facial ; the hypoglossal, and the dia- phragmatic (the phrenic.) f Mr. Bell has further established a difference in function between the facial nerve, (portio dura of the seventh pair,) and the branches of the fifth pair. He has proved, by his experiments, that the facial gives no impression of pain when it is cut, but that the effect of the operation is to abstract the parts upon which it is ramified from the influence of the respiratory motions. Lesions, on the contrary, of the fifth pair, produce pain, and the parts it supplies become insen- sible, when its branches are cut across. He still fur- ther cites cases, in which sensibility remained unim- paired, although the side of the face was completely paralyzed in its movements. Mr. Bell has given his attention more particularly to the' influence exerted by the facial nerve on respi- ration, and by the function of respiration on the parts that receive branches from this source. The facial he styles, in particular, nerve of expression. Being a * J F. Meckel, in his Manual of Anatomy, translated by Donne, ob- serves in a note on the accessory nerve, that it ,s wrongly called the accessor; of Willis, as it had previously been figured by Eustach.us, and described by Coiter. f See note on the page preceding. 46 nerve of motion, however, it may, independently of any additional consideration, be entitled a nerve of expression. That it may be influenced by respira- tion, no one will probably deny; but it may also un- questionably act independently of this function. Mr. Bell, indeed, has not in this instance adhered rigor- ously to his principle recognized in theory, and men- tioned above, viz., that no nerve performs two func- tions— the facial, on his own data, can only be a nerve of one kind of function. I chanced very lately to see a case where the vol- untary motion of the right side of the face was lost, whilst its sensibility remained ; both feeling and mo- tion on the left side were unimpaired ; movements of the tongue were also natural; but if the person attempted to spit, the saliva was always thrown to the right by the action of the left and healthy half of the cheeks and lips. M. Serres gives the case of a young man, who was constitutionally epileptic, and troubled with a slight ophthalmy in the right eye. The latter affection in- creased gradually, the cornea became opaque, the sight decayed more and more, and was, in fine, en- tirely destroyed ; the other organs of sense and motion on the same side were successively paralyzed ; the eye, eye-lid, nostril, and half of the tongue, lost their powers, whilst on the left they remained in a state of perfect integrity. This patient died. On dissection, there was found, first, an organic change of the gang- lion of the fifth pair ; it was enlarged, of a yellow color, and vascular below; second, a conversion of the nerve itself, at its insertion into the annular pro- 47 tuberance, into a yellow gelatinous-looking matter, similar to the ganglion, and penetrating, in little pro- cesses, the substance of the protuberances in the direction of the nervous insertions. The muscular branches of the nerve, however, were found healthy on the otherwise affected side ; the process of mas- tication therefore had never been injured. The difference in the functions of the facial nerve and fifth pair, afford a new proof of the distinction between nerves of feeling and nerves of motion. M. Magendie * found that sensibility was destroy- ed when the dorsal roots of the spinal nerves were cut through, and that motion suffered when the abdominal origins were the subjects of his experiments. He also observed that the abdominal side of the spinal cord was less sensible to pricking or cutting than the dorsal; but that the introduction of a probe along the axis of the part did not seem to have influence either upon mo- tion or sensation. The case of a man, who died in his sixty-sixth year at Charenton, seems to corroborate these ideas. During the last seven years of his life his organs of motion had been paralyzed, but those of sen- sation remained uninjured ; his intellectual faculties were almost annihilated, and his excretions were all involuntary. Thus reduced, he died. On opening the body, the pyramidal and olivary bodies were found pulpy, and of a dirty gray color. The same change was observed along nearly the whole of the anterior surface of the spinal cord, and penetrating through almost the whole thickness of the fibrous bundles * Journal de Physiologie Experimentale et Pathologique, torn. iii. 48 that compose it. The abdominal roots of the spinal nerves were still visible, but their consistence was much diminished. The dorsal surface of the cord, on the contrary, and its investing membranes, were in a healthy condition. I am, however, rather inclin- ed to question the accuracy of the report in reference to the brain and cerebellum, when they are stated to have been in a natural state ; for I observe that the skull was of an ivory hardness, and three times thicker than common. Such changes of the cranium are, I believe, constantly accompanied by alterations in the encephalic masses. M. Magendie also mentions a singular case, ob- served by M. Rullier, of a man who died at the age of forty-four. Up to his last hour this person pos- sessed great moral energies, strong generative pow- ers, free motion of his lower limbs, and perfect sen- sation in his upper extremities. The arms, however, were rigid, their muscles being permanently con- tracted, and often painful. They were rotated in- wards, and pressed to the sides of the body, from which they could not be separated, but with some considerable effort. The fore-arms were in a state of uneasy pronation, the hands flexed, and all the fingers bent. On dissecting the body, after death, ' the spinal cord, examined with care, appeared in its natural state, from its upper end as low down as the exit of the fourth pair of cervical nerves. The dorsal surface of its two lower thirds was also healthy; but between the portions named, and through a space corresponding to the branching of eight or nine pairs of nerves, (six or seven inches in extent,) there was 49 a very decided alteration. The spinal cord was there so extremely soft and diffluent, that the sheath formed by the dura mater seemed filled with a true fluid, which, indeed, flowed upwards or downwards, as the body was inclined. A puncture being made through the sheath, a considerable quantity of the fluid instantly escaped.' The last passage of this report, in reference to the puncture of the dura mater, does not seem to me very exact; because in a preceding sentence it is stated, that ' below the part of the arachnoid, which adher- ed to the spinal cord, its proper membrane seemed charged with a great number of vessels, both arteries and veins, all loaded with blood.' This description leads me to conceive that the dura mater was slit lengthwise, and separated from the arachnoid and proper investing membrane, of the spinal cord. If this were not so, the dura mater must then have ad- hered to the two inner membranes, and the puncture, consequently, could not have been confined to the first alone. 1 am confirmed in this opinion by what M. Magendie says, when he adds, that the man had probably lost a good third of the nervous matter of the spinal cord, that the communication between its cervical and dorsal parts was, so to say, maintained by the membrane only; for there seemed to remain no more of its entire thickness than a layer of white substance, scarcely two lines broad, and probably al- tered in its structure. The state of the nervous pairs, corresponding to the part of the spinal cord that was destroyed, ought also, in my opinion, to have been mentioned. Infor- 7 50 mation on the structure of the remaining thin layer of nervous substance would likewise have been in- teresting: was it composed of longitudinal fibres, serving as a means of communication between the upper and lower portions of the spinal cord ? Is it at all probable, that this office was performed by the sheath as stated ? If it was, the sheath, most cer- tainly, was neither the arachnoid nor the dura mater. The neurilema, that envelopes the pulpy nervous substance immediately, could alone execute such an office. M. Boulay, jun., veterinary surgeon at Paris, re- lates the case of a horse, whose hind legs were com- pletely paralyzed, whilst their sensibility was ex- treme. On opening his body, the whole of the lower part of the spinal cord was found soft and diffluent. There were no traces of change in the superior por- tion. The nervous substance of the lumbar and sacral pairs of nerves was of little consistence, and their sheaths were red and inflamed. The distinction of the nervous roots into dorsal and abdominal, accords with the two sorts of func- tion performed by the spinal mass. This subject, however, still requires elucidation ; for M. Magendie remarks, that 'when the posterior roots, covered even with their sheaths, are irritated, signs of ex- treme suffering are manifested ; and, what is par- ticularly deserving of notice, contractions of those muscles that receive nerves from below the place so irritated are excited; these contractions, too, only occur on the side of the body the nervous fibres of which are pricked.' According to the observations 51 of the same author, the abdominal surface of the spinal cord is not altogether insensible when irritated. The communication between the spinal cord and the nerves of the vegetative functions is also known to be established by means of fibres, which communicate directly with the abdominal roots of the spinal nerves ; nevertheless, the will has no influence over the functions of the viscera. Moreover, the fibres of the dorsal roots are evidently larger than those of % the abdominal; both are in proportion to the volume of the parts to which they are distributed, and both send off branches that run into muscles. It is im^ probable, therefore, that the dorsal roots are solely destined to general sensation. Neither does it seem to me at all likely, that the spinal cord and its nerves are mere conductors of sensation, and of volition in reference to motion. I rather conceive that they aid in maintaining the powers of those parts to which they are distributed ; for instance, that the muscles, or instruments of motion, acquire their power, in part, through the influence of their nerves, whilst the will to make the muscles act resides in the brain. Thus I do not believe that the only office of the spinal cord, with its nervous roots, is to establish a communication between external impressions and the brain, and between the brain and the instru- ments of motion —the muscles. To me it seems probable, that a very small part of the spinal cord suffices for these purposes ; the particular portion, or organ, however, cannot, in the present state of our knowledge, be specified. The experiments of M. Magendie prove the abdominal roots to include 52 the conductors of volition ; but as each of these is composed of two halves, the one superior, the other inferior, and, in man, of two distinct cords, it would be interesting to repeat and to extend the experi- ments, and by cutting the halves separately, to as- certain whether both propagate the dictates of ihe will; or, if this task is limited to one, to that, namely, which does not communicate with the in- tercostal nerves. The ganglions of the intercostal nerves, as well as those of the dorsal roots of the spinal cord, may possibly prevent the will influ- encing the functions of the parts, to which these nerves are distributed. The set of experiments instituted by Dr. Bellin- geri, and detailed in a Memoir read before the Royal Academy of Sciences at Turin, in February, 1824, do not tend to throw any new light on this interest- ing subject. They confirm the general idea upon the presence of separate nerves of sensation and of motion in the spinal cord ; but they farther accord motion to the nerves that issue from the dorsal roots. Dr. Bellingeri says, his experiments prove, 1st, that the posterior roots of the lumbar and sacral nerves produce the motions of extension in the lower ex- tremities ; 2d, that the posterior roots alone preside over sensation ; 3d, that the anterior roots produce the motions of flexion in the sacral extremities, and do not aid in perceiving external impressions; 4th, that the posterior bundles of the spinal cord preside over the motions of extension of the inferior extremi- ties, and have no connexion with perceptions of touch; 5th, that the white substance of the spinal 53 cord, and the nervous fibres that arise from it, are appropriated to motion ; and, 6thly, that the gray substance of the cord and the nervous fibres that spring from it,*belong to sensation. I have copied these statements from the ' Revue Encyclopedique,' vol. xxi. p. 723. The ' Bulletin des Sciences Medicales,' for June, 1825, also records these experiments, the inferences from which are in opposition to those deduced by M. Magendie from his own. I do not think, writh Dr. Bellingeri, that the verte- bral nerves can be divided into those which come from the white, and those which issue from the gray sub- stance of the spinal cord : because, on examining the structure of this part and its nerves, I find that the origins of the latter invariably present the same appearance : they are universally implanted, as it were, into the gray substance of the cord. From all I have said, it must be evident that I do not doubt the presenceof two distinct species of nerves among those that issue from the spinal cord in partic- ular, one propagating impressions from without, the other conveying the dictates of volition, in regard to motion, from within. This subject, however, is ob- viously involved in much obscurity, and will require ulterior and farther investigation, to be rendered clear. Let us now examine the structure of the nervous mass of the spine, known under the title of spinal cord, or spinal marrow. 54 CHAPTER I. Of the Nervous Mass of the Vertebral Column. The spinal cord is found in all vertebral animals, whilst in the avertebralia, such as worms, insects, the Crustacea, and mollusca, the nerves form masses, which are separate and distinct in the ratio of their functions The digestive powers of the avertebralia commonly'predominate over those of general sensibil- ity ; and the same ganglions that supply the viscera with nerves, also supply the muscles. In the verte- bralia, on the contrary, where sensation and motion play principal parts, there are particular nervous masses destined to each kind of function. The spinal cord having always the same functions, may be conveniently compared in the four classes of vertebral animals. In all, its structure is essentially the same ; modifications only are to be observed. General Considerations on the Spinal Cord of Man and Animals. The nervous mass of the spine is composed of two similar halves, one on each side of the mesial plane of the body. They are parted to a certain depth by two longitudinal clefts; the one, of course, on the dorsal, (pi. i. fig. 5, 5 — 5) the other on the abdomi- nal surface, (pi. i. fig. 4, 5—5) and united between these fissures by a commissure, or apparatus of union, 55 (pi. i. fig. 6 and 7. a — a.) This commissure is pierced in its interior by a canal, which is more or less distinct in different animals, (pi. i. fig. 8 and 9,) and is especially visible during the earliest periods of life. The canal of the spinal cord has given rise to much discussion, and nothing certain is even now concluded in regard to it, either as to the space it occupies, or to the mode of its formation. Before explaining my own views upon this point, I shall quote a.passage, published in the first volume of our large work on the ' Anatomy and Physiology of the Brain and Nervous System.' ' M. Demangeon and Messrs. Devilliers, uncle and nephew, afforded us the opportunity of examining a case of Spina bifida, conjoined with considerable hy- drocephalus. From the second to the fourth lumbar vertebra, the spinous processes of which were want- ing, there extended a membraneous pouch about two inches in diameter. During the eighteen days which the child survived its birth, a great quantity of fluid exuded continually from this pouch. Having cut away some of the other vertebrae, we observed no swelling of the dura mater, neither did any fluid escape when we slit open this membrane lengthwise. It was only between the arachnoid and the proper vascular coat, that a small quantity had accumulated, and it commuuicated with the pouch. ' The spinal cord was of its usual form. We shook the head, and turned it in every direction, but could perceive no communication between the water col- lected in the ventricles of the cerebral hemispheres and the spinal cord or its membranes. 56 ' To learn, positively, whether or not any commu- nication did exist between the pouch and interior of the spinal cord, we cut this across in the neck : it appeared in the usual state ; on blowing, however, through a pipe upon the transverse cut, each half of the cord presented an opening, about the magnitude of a middle-sized goose-quill. The two canals were separated by the commissure. We could not inflate the spinal cord through its entire length at once. We could only effect this partially. Downwards, the air penetrated freely for three inches, but there the canals were no farther pervious, so that no com- munication existed between them and the pouch. Neither could we perceive that there was any fluid in the canals. The pouch, itself, was formed partly by the dura mater and tunica arachnoides. Its supe- rior edge touched the lower extremity of the spinal cord. Although we had blown into the two halves of the spinal marrow in so easy and uniform a man- ner, we still could not determine whether the canals were to be considered as an effect of disease or not. We, therefore, examined the spines of children at the period of birth, of others somewhat older, and of adults ; in all we discovered a corresponding organi- zation. We, however, found that the canals did not expand before the blow-pipe so readily in children somewhat advanced, and in adults, as they did in subjects in the earliest infancy ; we, therefore, to show the fact, prefer the bodies of newly-born chil- dren. In other respects, precisely similar openings on each side are to be observed in all; the interior sur- faces too, being always smooth. If the blowing into 57 the canals be continued from below until as many as six or eight lines are opened, and only five or six lines are cut off in succession, so that the opening may be always maintained, the canals may be fol- lowed into the medulla oblongata, the tuber annulare, under the corpora quadrigemina, through the crura cerebri, and even on to the supposed optic thalami and the commencement of the corpora striata. Al- though no opening be observable into the fourth ven- tricle, nor into the aqueduct of Sylvius, nor into any other of the cerebral cavities, this structure, never- theless, would incline us to admit the possibility of a fluid being secreted by the canals, and producing a true dropsy of one or both cavities of the spinal cord. ' Each half of the spinal cord, then, may be consid- ered as a membrane doubled on itself, along the mid- dle line of which the gray substance, although with- out apparent division, may, by a slight blast, be sep- arated, so as to form the sides of a canal. ' No violent separation can here be supposed ; for, in the first place, it is effected with perfect ease, whilst in other situations, and even where the gray substance is much softer, no disjunction can be ef- fected without the greater difficulty. Secondly, where a separation of parts is the consequence of violence, the edges are ragged and uneven; whilst in the case cited, the surfaces are continuous and smooth. Thirdly, the openings in the situations mentioned, are always found in the same places, are perfectly equal, being sometimes quite round, sometimes oval- shaped, sometimes slightly angular, and running now 8 58 horizontally, then vertically, obliquely, or in a semi- circular direction, according as the curves of the medulla oblongata, of the pons Varolii, of the crura cerebri, of the optic thalami, or the parts that sur- round the canal determine. If the air be propelled too forcibly, the canal will burst where the gray sub- stance is the most slightly covered by nerves, as at the places where the nerves issue, although the tear- ing off of these does not, of itself, give any outlet to the air.' Since the above was written, I have seen reason to change my opinion, and I now consider the canals to be mere effects of the blowing. I have produced them in birds and fishes, as well as in man. They are not, however, I must here observe, to be con- founded with the true canal of the spinal cord — the canal that exists in the interior of the commissure or apparatus of union. This is quite uniform, and is occasionally the seat of disease, getting filled with serum. It is more or less distinct in animals of the inferior classes, and in the embryos of those of supe- rior tribes. In the human foetus, it is commonly visible during the first four or five months from con- ception. After this date it is generally, though not invariably, obliterated. This explains how its existence has been at one time admitted, at another denied, and how, in extraordinary cases, it has even been found in advanced old age, as Charles Etienne, Columbus, Morgagni, Senac, Portal, and other authors have observed. The canal of the spinal cord appears to be analogous to the aqueduct of Sylvius. 59 M. Serres has said that the spinal marrow in young embryos consists of two cords, which unite first in front and compose a gutter, but which coming together' speedily get blended behind. The interior of the spinal marrow is then hollow, and forms a long canal, which is gradually filled up by the depo- sition of successive layers of gray substance secreted by the pia mater, which has insinuated itself into the canal. fc This account does not appear to me correct and conformable to nature. I allow that the two cords unite at the bottoms of the clefts ; but 1 likewise maintain that each contains gray matter in its in- terior, in the direction of the two nervous roots that are implanted. But were the spinal mass devel- oped, and its canal obliterated, as M. Serres would have us believe, by the deposition of gray substance in successive layers, this process ought, evidently, to go on in the interior of each of the cords compos- ing it, and not in the canal between the two similar halves. The corresponding parts of each half of the spinal cord are voluminous in the ratio of their implanted nerves. This proposition is strikingly exemplified, by comparing the spinal cord of animals, whose supe- rior are larger than their inferior extremities, with that of others, whose inferior are of greater size than their superior limbs. 1 have already said that there is a mass of gray sub- stance contained in the interior of each half of the spinal cord, proportionate, in quantity, to the volume of the corresponding parts of the same, and to the so nervous roots that issue at the same place. The gray substance is disposed in a crescent form on each side of the apparatus of union, towards which its con- cave aspects are turned. (PL i. fig. 9 and 10.) The white fibres of the spinal cord, on both the abdominal and dorsal surfaces, follow the gray sub- stance throughout its extent, so that there are two nervous roots in each half: one dorsal, another ab- dominal. (PL i. fig. 9 and 10.) The dorsal roots, generally, and the entire dorsal mass (PL i. fig. 9 and 10,) are more considerable than the abdominal roots and corresponding half. The dorsal roots com- municate with the intervertebral ganglions (pi. i. fig. 3, 4, a—a,) and the latter are proportionate to the former. No division of the spinal cord into dorsal and ab- dominal portions is effected by two such channels as separate it laterally into halves ; it is, at most, only marked by ligamenlum dentatum by which the cord, on each side, is attached to the dura mater. (PL i. fig. 3, 4, 5, and 6.) Neither is it proper to view the lateral portions of the spinal cord, as composed of three bundles extending from one of its extremities to the other. They are much rather to be consid- ered as nervous membranes folded on themselves, and forming a tube, containing gray substance. (PL i. fig. 10.) The fissures on the abdominal and dorsal aspects of the spinal cord, are quite constant. The first is shallower, but more conspicuous, than the other (PL i. fig. 10.) The abdominal nervous roots of the spinal cord 61 communicate with the nerves of the thorax and ab- domen ; those of the dorsal surface frequently in- osculate, and filaments from one pair of nerves often run to join the fasciculi composing another. (PL i. fig. 5.) Among the general considerations on the spinal cord, the question respecting its uses still remains for examination. Anatomists have been in the frequent habit of speaking of a central mass in the nervous system, from which they conceive all its other parts to arise. The brain, cerebellum, and spinal cord, have very commonly been so entitled. M. de Blainville, how- ever, separates the brain and cerebellum from the central mass. These he arranges, along with the external senses and intervertebral ganglions, under the general title, Ganglionary portion of the nervous system; and he confines the central mass exclusive- ly to the spinal cord and medulla oblongata. In his view, the ganglionary is only added to, and not de- rived from, or produced by, the central portion. The two nervous roots of the spinal cord are, he says, mere fibres of communication between the central part of the nervous system and the nerves of sensation and voluntary motion, which originate in the inter- vertebral ganglions. To me, anatomical, as well as physiological, facts, seem to militate against this opinion of M. de Blain- ville. In the first place, the intervertebral ganglions belong to the dorsal roots only of the spinal nerves. Our author, consequently, forgets to mention the origin and use of the abdominal roots entirely. But 62 is it not probable, that both dorsal and abdominal roots arise in the same manner ? The filaments of the spinal roots, too, are in proportion to the corres- ponding masses of the cord whence they issue. Now, as the abdominal roots have no intervertebral ganglions, and as they are evidently detached from the spinal cord, ought we not to conclude that the dorsal roots are so in like manner ? Another proof of the erroneousness of M. de Blain- ville's opinion, exists in the size of the nervous fila- ments of the spinal cord. The apparatus of commu- nication is never so large as the parts that communi- cate : what a difference, for example, between the volume of the nervous masses of vegetative and of phrenic life, and their communicating fibres ! Neither is M. de Blainville's opinion supported by- physiology. The ganglionary portion, he conceives to be sufficient for the performance of its own func- tions ; that is to say, adequate of itself to feel, and to cause the execution of voluntary motion ; what then becomes of the central portion ? what is its use ? Admitting it to establish communications between the different parts of the nervous system, it cannot, however, exist solely for such a purpose ; its volume is by much too considerable to permit such a suppo- sition to be entertained. Again, it most certainly is not destined to the affective and intellectual opera- tions, for there is no proportion between them and the development of the spinal cord. On the con- trary, it is certain that general sensation and volun- tary motion are in direct relation to the volume of the nervous masses of the vertebral column. Ani- 63 mals, eminently endowed with these two functions, have always a considerable spinal cord, and its parts are proportionate to the organs which receive their nerves from thence. The several parts of the spinal cord are also augmented, as the apparatuses of sen- sation and of motion are increased in number or size. Further, the spinal cord is developed at a much earlier period of life than the cerebral masses : it has acquir- ed solidity and firmness, while the brain is still pulpy and devoid of fibres ; and, in harmony with this law, children display great muscular activity, — their love of bodily exercise is insatiable, before their mental faculties appear in any degree of vigor. M. Serres, who admits all the organic systems, the nervous in particular, to be developed from the cir- cumference towards the centre, maintains that the nerves are fully developed when the spinal cord and brain are still in a fluid state. In conformity with this his hypothesis, he denies that the spinal cord gives origin to its nerves. These, according to him, are only implanted into it. Dr. Bailly conceives, as I have said, the same'ner- vous elements to belong to every particular vertebra, i. e., nerves of sensation, of motion, of digestion, and of the intellectual functions. He speaks of eight cords that compose the intellectual system of the vertebral column: the superior median cord, contin- uous with the pyramidal eminence, and terminating anteriorly in the cerebral hemisphere ; the lateral in- ferior cord, ending in the internal layer of the corpo- ra quadrigemjna ; the superior lateral cord, which terminates in the cerebellum; and the inferior me- 64 dian cord, ending in the lateral convolutions of the medulla, — convolutions which are most largely de- veloped in cartilaginous fishes, and which correspond to the ribbon of gray substance of mammiferous ani- mals. These eight longitudinal cords, four on each side, according to this author, exercise functions analogous to those of the cerebral hemispheres, the internal slip of the quadrigeminal bodies, the cerebel- lum, and the lateral convolutions of the fourth ver- tricle in fishes, or the gray band in the mammalia. The medulla oblongata, in the same gentleman's view, presents alternately an intellectual cord and a nervous pair. These physiological suppositions will, I make no doubt, share the fate of so many others, that are now forgotten. In my opinion, the spinal cord is, 1st, the origin of the nerves styled spinal; 2d, an ap- paratus that contributes to muscular and sensitive powers ; and 3d, a means of communication between the cerebral operations, the sense of touch, the pow- er of motion in general, and the functions of vegeta- tive life collectively. Particular Considerations in regard to the Spinal Cord. Before the development of the extremities in the embryo, in animals also that naturally have none, and in cases of monstrosity where they are want- ing, the spinal cord has no enlargements. These appear with, and are in proportion to, the extrem- ities. 65 In the lower animals the spinal cord extends far- ther into its bony canal than in the human kind. Up to the fourth month of the human embryo's ex- istence, it runs to the extremity of the coccyx ; but the peculiar structure, termed cauda equina, which is more remarkable in man than in any other animal, becomes more and more apparent after this period. The caudal appearance is produced by the sacral and lumbar nerves. The spinal cord of the human kind commonly ter- minates by one or two little knobs, (of which the superior, when there are two, is the larger,) opposite to the second lumbar vertebra, and it is then attached by means of a tendinous slip to the bottom of the ver- tebral canal. The spinal cord is commonly divided into four portions: a cervical, dorsal, lumbar, and sacral. Each of these detaches several pairs of nerves, the number of which varies in different species of ani- mals ; in man it amounts to thirty pairs, five being sa- cral, a like number lumbar, twelve dorsal, and seven cervical. The spinal cord of man, as of animals, is enlarged, and contains a larger quantity of gray substance at those places where the great nerves of the extrem- ities are detached, than at any other. Although many anatomists, M. Serres among the rest, deny that'the spinal cord of man and animals is enlarged at, and contracted between, the origin of each pair of nerves, I still adhere to the opinion which, in con- junction with Dr. Gall, I published long ago; and I again appeal to nature for confirmation of its accu- 66 racy. These alternate enlargements and contrac- tions are more or less conspicuous, in the ratio of the volume of the nervous pairs ; they are, for instance, more apparent in the ox and horse than in man. If, however, the human spinal cord, stripped of its dura mater and arachnoid covering, be held profile-wise against the light, the undulated line of its edges will be abundantly obvious. In the large work on the ' Anatomy of the Brain and Nervous System,'we have given drawings of this structure from the spinal cord of the calf, and of man. PL i. fig. 3, is a portion of the spinal cord of a calf. Several anatomists have spoken of numerous trans- verse folds to be observed, especially on the abdomi- nal surface of the spinal cord ; these become very distinct when the cord is taken from out its bony canal, and one end is brought towards the other; they disappear entirely, however, when the part is stretched. Such folds, therefore, appear to result from the bending of the cord, and not to belong to any original peculiarity of organization. On either side, and at some little distance from the great median fissure, two superficial channels may be observed on the dorsal surface of the human spinal cord (PL i. fig. 5, a—a.) They extend as far as, or a little way beyond, the first dorsal vertebra. The two bands between the median and these su- perficial fissures, are developed at the earliest peri- od ; their structure is even complete, when the rest of the spinal cord is still a grayish and pulpy mass. The bands on the external edges of the dorsal and abdominal median fissures, appear, in general, to at- 67 tain maturity of structure before any of the lateral masses. By opening the mesial abdominal fissure, and stripping off the vascular tissue, the nervous fibres will be seen running lengthwise and parallel to the lateral bands, (pi. i. fig. 6 ;) but in the dorsal cleft, they will be found descending perpendicu- larly from the surface towards its bottom. (PL i. fig. 7.) The structure of the apparatus of union has not the same appearance at the bottom of both fissures. If the edges of the one on the dorsal aspect be gent- ly separated, two white bands will be discovered running lengthwise (pi. i. fig- 7, a—a), almost as occurs in the middle line of the great cerebral com- missure (raphe of the corpus callosum) ; on the bot- tom of the abdominal fissure, on the contrary, fila- ments will be observed running transversely from the sides towards the median line. These bundles do not meet; they rather interlace, each terminating on either side between the two that come from the op- posite side. (PL i. fig. 6, a—a.) Besides the peculiarities of its shortness compared with the vertebral canal, and of its termination in the cauda equina, the spinal cord of man presents another striking peculiarity in the direction in which its nerves are detached. The direction in which the spinal nerves are sent off, varies widely in different classes of animals. In man, their course is down- wards and outwards : this depends evidently on the vertical posture, by which man is distinguished from the other mammalia, and on the shortness of his spinal 68 cord compared with its bony canal. In the human kind, only the first pair of cervical nervous roots on the dorsal surface (pi. i. fig. 5), and the two first pairs upon the abdominal (pi. i. fig. 4), have one set of bundles coming from above, downwards, and another from below, upwards ; all the other pairs are detached more and more obliquely downwards, to gain the vertebral holes by which they issue, in pro- portion as they arise nearer to the sacral extremity of the spinal cord. In other animals, on the contra- ry, whose spinal nervous masses occupy the entire length of the vertebral canal, the nerves are sent off directly opposite to the intervertebral spaces at which they issue. (PL i. fig. 3.) I have still to speak of the superior extremity of the spinal cord. By the words spinal marrow or cord, most anatomists understand the nervous mass that extends throughout the spinal canal up to the occipital hole; others, Messrs. Scemmerring and Chaussier among the number, say that it goes as far as the annular protuberance. They consequently include the pyramidal and olivary bodies, the acces- sory, pneumogastric, glossopharyngeal and hypoglos- sal nerves ; all the mass, in short, commonly named medulla oblongata. They speak of two portions —■ one cranial, another spinal, of the spinal cord ; the first being, of course, contained in the skull, the sec- ond in the canal of the vertebral column. The organization of the spinal nervous mass can- not be said to change entirely when it enters the cra- nium : several pairs of nerves are still detached pre- 69 cisely in the same manner as they are in the spine: the nerves too, in both cases, perform similar func- tions. The proper spinal masses are also intimately connected with those of the medulla oblongata. In this last part, however, the abdominal fissure is in- terrupted by the decussating bundles of the pyramidal bodies : the size of the mass is also very sensibly in- creased here, and there is no regular proportion between the proper spinal cord and the mass that extends from the occipital hole to the annular protu- berance. Moreover, the roots of several cerebral nerves, as they are styled, are found in this last mass, as also the rudimentary parts of the brain and cere- bellum. Lastly, the word spinal refers to a particu- lar situation — the spine. These reasons may suffice to make us limit the title spinal cord to the mass in- cluded in the vertebral canal, and extending from the occipital hole, or commencement of the pyra- midal decussation to the cauda equina or horse s tail. 70 CHAPTER II. Of the pretended Cerebral Nerves ; or, of the Cranial Nerves of the External Senses and Voluntary Motion. It is usual for anatomists to consider the nervous mass lying between the occipital hole and annular protuberance, as distinct and particular. In former times, this part was taken for a prolongation of the brain and cerebellum, and, therefore, called medulla oblongata. In man it is composed of parts, named severally, pyramidal bodies, which are two in num- ber, anterior (pi. vi. fig. 1., 1—c.) and posterior (pi. xi. in the middle line) ; olivary bodies (pi. vi. fig. 1, a.) ; restifoi m bodies (pi. xi. e. e.) ; accessory nerves (pi. i. fig. 3, 4, and 5; pi. vi. fig. 1, 2—3): hypo- glossal nerves (pi. vi. 4) ; pneumogastric nerves (ib. 6) ; glossopharyngeal nerves (ib. 7) ; auditory nerves (ib. 9) ; facial nerves (ib. 11) ; and abductor nerves (ib. 10.) At the conclusion of the last chapter, I remarked that it was a mistake to confound the part called medulla oblongata and the spinal cord together. I here subjoin that the medulla oblongata is not a sep- arate and particular nervous mass : it gives origin to the nerves above mentioned, and also to the fifth pair ; but there is yet one portion of each of its halves which belongs, decidedly, to the cerebellum, and another which pertains to the brain. 71 The volume oUthe medulla oblongata varies great- ly in the different classes of animals: its size is de- termined by the nerves that arise from it, and by the bundles that proceed to the cerebellum and brain. Its increase beyond the size of the spinal cord, is more remarkable in reptiles than in fishes, in birds than in reptiles, and is especially considerable in the mammalia, which, generally, have the medulla oblongata as well as spinal cord proportionately larger than man, because the nerves detached from these parts are larger in them than in the human kind. At present, I mean only to speak of the supposed cerebral nerves. The pyramidal, olivary, and resti- form bodies will be examined with the cerebellum and brain of which they are parts. The opinions of authors upon the origin of the nerves of the head are very various. In general theyfare derived from the brain—hence their name cerebral. But some writers limit the title brain to the hemispheres, and join the striated bodies, the optic thalami, the cerebral legs and annular protu- berance to the medulla oblongata ; or, otherwise, they look on all these as parts of the spinal cord, and then say that no nerve whatever arises from the brain, that is, the hemispheres, immediately. By thus extending the limits of the medulla oblongata and spinal cord, however, parts that belong essen- tially to the brain are included. The principle we lay down, therefore, that no nerve originates in the brain, and that every nervous part has its own ori- 72 gin, so that the nerves can no more be derived from the brain than can the various nervous pairs from each other, cannot possibly be confounded with any of the foregoing opinions of authors. The proofs we adduce in support of our position, as to the independent origin of the various nervous parts, are constantly the same; all, therefore, that has been said to demonstrate the spinal cord to be no continuation of the brain, applies to the nerves of the head, and proves that they do not owe their be- ing to the brain, and that no one pair derives its ex- istence from any other. In the first place, the nerves of the head bear no proportion to the brain in size; and then,, these nerves exist in acephalous monsters, whose brain never had being. Moreover, the course taken by the nerves towards the cranial holes through which they pass, proves, in the most positive manner, that they are not continuations of the cerebral fibres. In examining the individual nerves, I shall speak of their several peculiarities, as origin, structure, and connexion are concerned. The nerves of the head, as of the spine, have been long classed into pairs. The number of pairs reck- oned, however, varies considerably ; sometimes they are said to be seven, sometimes eight, or nine, or, ac- cording to M. Scemmerring's method of counting as many as twelve. However, the mode of indicating the several pairs of nerves numerically, and speaking of the first pair, the second pair, the third pair, and so on possesses no practical advantages, because, be- sides the number, the functions of each pair must still be learned. It is better, therefore, to designate 73 each pair of the cranial nerves in succession from its functions or its destination.* Some authors have divided the nerves according to their places of detachment, into nerves of the brain, of the cerebellum, of the annular protuberance, and of the medulla oblongata. This attempt at clas- sification is necessarily very deficient, for it is based upon an error in regard to the origins of the nerves ; the actual place of origin being confounded with that at which they issue immediately from the gen- eral mass. Of the Accessory Nerve. — Spinal, or Spinal accessory of Willis. — 3d Branch of the 8th pair of J. Bell. — Superior respiratory of C. Bell. The accessory nerve is found in man and the other mammalia. (PL i. fig. 3, 4, 5, and pi. vi. fig. 1, 2—3.) It arises from thecervico-spinal mass and medulla oblongata. Its filaments come from the dorsal surface of these parts, and vary in number, in thickness, and in length, not only in different indi- viduals of different species, but even on the two sides of the same subject. The first filaments are detached at various heights, sometimes higher, some- times lower, in the spinal cord, issuing from the level * In order to diminish somewhat of the confusion arising from a peru- sal of the various works on the brain and nervous system, each posses- sing a nomenclature different from the others, it has been thought proper to add some of their synonyms to each of the cranial nerves. E. 10 74 of the seventh cervical pair in one instance, and from that of the fifth in another. The accessory recedes from the spinal cord and medulla oblongata, as it approaches the pneumogastric nerve, along with which it escapes from the cranium. I have already said, that Mr. Charles Bell arranges the accessory among the nerves of respiration. In contributing to this function, it produces motion, and is in- fluenced by the will: nevertheless, it is detached, as we have seen, from the dorsal surface of the spi- nal cord. Of the Pneumogastric Nerve. — Par vagum. — Mid- dle sympathetic. — Vocal. — Pulmonary 2d branch of the 8th pair. The pneumogastric occurs in all vertebral animals. In man (pi. vi. fig. 1, 6,) it issues by numerous fila- ments between the olivary, (ibid, a,) and the resti- form (e e) bodies : nearer to the latter, however, than to the former. It unites with a great number of other nerves,, a circumstance that has obtained for it the title vagus. Its branches run to the larynx and pharynx, to the thyroid gland, the vessels of the neck, and the great conduits of the heart, to the lungs, the liver, spleen, pancreas, stomach, and duodenum. As some of its principal branches are distributed to the organs of voice, and as its lesions derange the functions of these parts, it has also been called the vocal nerve. The communications by its means established, and its extensive distribution, ex- 75 plain the sympathies that exist between the throat, lungs, stomach, heart, &c. Of the Glossopharyngeal Nerve. In the mammalia and man, (pi. vi. fig. I, 7,) this nerve comes off from the medulla oblongata, just be- fore the pneumogastric, by a great many filaments, which, speedily uniting into one or more bundles, compose a trunk that runs to supply the pharynx and muscles of the tongue. It appears to be destined to general sensation. Of the Hypoglossal Nerve.— 9th pair of Willis. — Gustatorius of Winslow. — Singualis of Vicq.d? Azyr. — Sublingual. The hypoglossal in man arises partly near the oli- vary and pyramidal bodies, and partly lower down, by several filaments that are detached, and get united after the manner of the cervical nerves. (PL vi. fig. 1, 4.) It supplies the tongue with motive power, and acts in mastication, deglutition, speaking, singing, &c. Of the Abductor Nerve of the Eye. — 6th pair of Willis.—External Motor of Meckel. This nerve arises in all mammiferous animals, from the abdominal surface of the medulla oblongata. 76 (PL vi. fig. 1, 10.) In some, as the horse, ox, and deer, it mounts all the way along with, and by the side of, the pyramidal bodies, in the form of a band, which, on reaching the annular protuberance, divides into two. In the human subject it is generally cov- ered by some transverse fibres of the protuberance. Its distribution, as its name implies, is to the abduc- tor muscle of the eye.* Of the Facial Nerve. — Portio Dura of the 1th pair. — Nervicus communicans faciei of J. Bell. The facial is detached from the spinal cord in the same manner as the nerves I have just discussed. Its true origin is readily seen in the lower animals ; but in man, (pi. vi. fig. 1, 11,) it (or some of its fila- ments at least) seems to come from the annular pro- tuberance. This happens in consequence of its be- ing covered entirely, or partially, by the transverse fibres of the part mentioned. The distribution of this nerve is to the muscles of the face ; it also com- municates freely with all the three branches of the fifth pair. Of the Motor Nerve of the Eye. — 3d pair of Willis. — The common Motor of Meckel. The filaments composing this nerve, (pi. vi. and * The origin of this nerve seems not to be confined to any particular spot. The editor has seen it arise at the pyramidal decussation, in the brain of a negro, and pass over and by the sides of the olivary bodies. In another brain, he has observed it arise from the annular protuber- ance, about a line from the base of the pyramidal bodies. 77 pi. x. fig. 1, 15,) issue from the blackish body of the cerebral legs (pi. x. fig. 1, 30) ; these unite and go to supply the superior, internal, inferior straight, and inferior oblique, muscles of the eye, and the elevator of the upper eye-lid. It is detached in all vertebral animals, from the cerebral crura behind the tuber cinereum, or ash-colored tubercle, (pi. vi. 17,) which is situated immediately behind the junction of the optic nerves. Of the Nerve of the Superior Oblique Muscle of the Eye. — 4^pair or Patheticus of Willis.—Troch- learis. — Internal Motor of Meckel. This nerve, (pi. vi. 13,) springs by several fila- ments behind the posterior pair of quadrigeminal bodies in the mammalia, (pi. xi. fig. 1, o,) and be- hind the bigeminal bodies in the other classes of ani- mals. It has no prerogative over the other nerves of motion in expressing the affections and passions; the name patheticus, or ogling nerve, therefore, which it has obtained, is misapplied. Although a nerve of motion, it arises from the dorsal surface of the nervous mass. Of the trigeminal Nerve. — bth pair of Willis. — Tri- facial of Meckel*. The trigeminal (pi. vi. fig. 1, 12,) arises from the medulla oblongata. Its place of origin is apparent 78 in those animals, as reptiles, birds, and fishes, which have no annular protuberance, and also in the mam- malia which have it of small size ; but in man, the monkey, and other tribes, where this part is very large, the trigeminal seems to arise from it: the nerve, however, is, in fact, only covered by some of its transverse fibres, (pi. viii. fig. 1, i—k,) and the origin of the nerve is, in fact, the same in all animals. To show it in the human kind, the fibres of the an- nular protuberance that cover it, must, of course, be dissected away. The trigeminal nerve is distributed to every part of the face, to the muscles of the forehead, of the eyelids, nose, lips, jaws, and ears ; it communicates with the organs of all the five senses, and of volun- tary motion, and brings these and the other parts of the body, the. face, neck, trunk, and extremities, into mutual relationship. One branch of the trigeminal is ramified on the tongue, and is regarded as the true gustatory nerve. It is, therefore, destined to take cognizance of an impression of a specific kind, viz. taste. If some feel disposed to regard taste as a sort of touch, they must, at least, admit the impossibility of confounding or assimilating this species of perception with sensa- tion in general. 79 Of the Auditory Nerve. — Portio Mollis of the 1th pair. — Acoustic Nerve. The auditory (pi. vi. 9,) as well as the nerve last discussed, must exist in the avertebral tribes, but its origin and peripheral expansion only become distinct and complex as we ascend in the scale of beings. The origin of the auditory nerve is in many fishes confounded with that of the facial and trigeminal: in some kinds, however, it is more distinct, and is the same as in reptiles and birds. The auditory nerve always arises laterally and posteriorly to the cerebellum. In the mammalia it comes from the fourth ventricle, and traverses in its course a band of gray substance, lying between the restiform body and the cerebellum. In man certain white lines may com- monly be seen in the fourth ventricle, (pi. xi. fig. 1. t,) which Piccoluomini was the first to consider as the origins of the auditory nerve. These lines, or streaks, are almost imperceptible in some subjects, but in others they are very numerous and distinct. They are observed to vary on each side, being occa- sionally larger and more numerous on one than on the other. Sometimes they occur disposed in rays, sometimes in pencils, and, again, they run parallel, often lying higher on one than on the other side. They at one time appear as little flattened bands, at another as rounded and salient cords. Piccoluomi- ni's opinion of their use seems now to be very gen- erally adopted ; it is certain, indeed, that some of them do unite with the auditory nerve, but others 80 run to the anterior cerebellar lobes, and others dip into the middle of the cerebellum. Although many of the mammalia have much larger auditory nerves than man, these white fibres are nevertheless want- ing in all. In them, there is a broad band on either side, extending from the one auditory nerve to the other, immediately behind die annuhr protuber- ance, and above all the ascending bundles, except the pyramidal bodies. (PL iv. fig. 2, c.) This band appears to be an apparatus of union or a commissure. It does not give origin to the facial nerve, as some anatomists have supposed. Of the Optic Nerve. — 2d pair of Willis. Since the days of Eustachiusand Varolius,the ma- jority of anatomists have derived this nerve (pi. vi. fig. 1, 20,) from certain masses, which have, in con- sequence, been entitled thalami of the optic nerves. (PL x. fig. I, p.) Others, however, followed some of its fibres backwards to the anterior of the quadri- geminal bodies. (£l. xi. fig. 1, n.) And it is easy in the mammalia to do this. A broad slip issues from the anterior quadrigeminal body of either side, which turns round upon the outer edge of the thala- mus, simply superimposed upon the cerebral crura, but attached to the neighboring masses along its ex- ternal edge, as far as its junction with its fellow of the opposite side. (PL viii. fig. 1, w, w, w.) From the tuber cinereum, (pi. vi. fig. I. 17,) the optic nerve receives many additional fibres, which join it 8! in right lines, and without decussating. (PL viii. fig. 2, 20.) It is the opinion of many anatomists, that the op- tic nerves, at their junction, unite intimately with- out decussating ; many others, on the contrary, think that either nerve crosses to the side opposite to that on which it had arisen. The numerous cases de- scribed by authors, and the facts which Dr. Gall and I have collected, prove that atrophy of one optic nerve is continued on the opposite side after the junction of the two. We, therefore, agree with those who recognize a partial decussation of optic nerves in man and the mammalia. The fibres of the outermost portions ap- pear to continue their course onwards without de- cussating. It was a great error to consider the eminences called optic thalami, as the sources of the optic nerves. There is, in fact, no proportion whatever between these parts and the nerves of vision. In the horse, ox, sheep, &c, the optic nerves are as large as in man, but the thalami, in the human kind, are much larger than in these animals. A very cursory examination of the structure of the thalami also shows a mere superficial layer at- tached to the optic nerve and the whole of the in- terior fibres proceeding in a divergent manner, backwards, to be distributed to the cerebral convolu- tions. (PL x. fig. 1, p. P. P.) When the optic nerve is affected with atrophy, the corresponding thalamus is diminished only in as far as the nerve itself is lessened; the interior of the 11 82 thalamus suffers no change, but the atrophy of the nerve continues on to the anterior quadrigeminal body which belongs to it. I once found, in the brain of a woman who had died insane, the thalamus of the left side half converted into pus ; the corpus stria- tum of the same side was also much shrunk, but the optic nerve was healthy, and resembled, in all res- pects, its fellow of the opposite side, in the vicinity of which no organic change could be detected. The interior pair of quadrigeminal bodies were also in their natural state. The two thalami are rarely of equal size ; the one on the left side is commonly the smaller. It, there- fore becomes necessary to guard against attributing to atrophy of an optic nerve an appearance that de- pends on natural conformation. Until Dr. Gall and I showed the mistake, the op- tic tubercles of birds and reptiles were confounded with the thalami; these tubercles (pi. xi. fig. 2 and 3, n,) however, correspond to the anterior pair of quadrigeminal bodies. The parts, called thalami (pi. xi. fig. 2, p.,) also exist in the two classes of creatures mentioned, besides the true optic gang- lions, (ib. n.) It is a difficult matter to say whether the long elevated bodies that occur immediately behind the crossing of the optic nerves in fishes (pi. ii. fig. 4, 6, 8, 16,) and correspond to the optic ganglions of birds, that is to say, to the pair of ganglions (pi. iii. fig. 5, 6, 7, 10, and 11, n.) which comes immediately after the cerebellum, or whether they ought to be likened to the bodies which are styled mammillary. 83 (PL vi. fig. 1, 16.) The optic nerves of fishes seem to arise from, at all events they communicate with, these bodies. By comparing pi. ii. fig. 4 and 6, 16, with pi. iii. fig. 12, n., the optic ganglions in birds, and especially in mammiferous animals, will be seen to be separated and pushed upwardly and laterally by the medulla oblongata, cerebral legs, and annular protuberance. Moreover, the optic nerves in fishes adhere to several other parts, as they do in the higher classes of vertebral animals and in man. It is from this circumstance that a great part of the other masses, especially those that follow the cerebellum, are called optic ganglions ; but these bear no pro- portion to the optic nerves (pi. ii. fig. 5, 7, and 10, n.,) and to me, it seems more reasonable to allow, with M. Arsaky*, that the complicated structure of the optic ganglions in fishes, explains the functions of the derived nerves, which, in reptiles, birds, and the mammalia, are evidently aided in their functions by the other parts with which they communicate. The implantation of the optic nerve of fishes into the inner edge of its ganglion, which causes the greatest part of this mass to appear before and above it, bears a striking analogy to the adhesion of the same nerve to the brain in other classes of animals, and confirms the idea in question. It is rendered still more probable, as the same peculiarity of struc- ture is found in connexion with the olfactory nerves of fishes. And further, the oblong bodies, which, in fishes, lie behind the crossing of the optic nerves, *Dissertatio de Piscium Cerebro et Medulla Spinali; Halee. 1813- 84 cannot possibly be supposed analogous to the mam- millary bodies of mammiferous tribes, because these last belong to the fornix, and this is a part which fishes have not. I may still add that the mammillary bodies bear no proportion to the optic nerves, and that the oblong bodies of fishes above mentioned do, regularly. The oblong bodies of fishes, probably, correspond to the gray tubercle, (tuber cinereum) of the mam- malia. This tubercle, in the higher classes of be- ings, always sends fibres to the optic nerves, which, after this accession, advance of increased size in their course. (PI. viii. fig. 2—17.) The connexion of the optic nerve with such a number of cerebral parts, renders its exact origin un- certain. To appreciate this truth in its full force, it will be necessary to reflect on what 1 have still to say of the quadrigeminal bodies. Of the Quadrigeminal Bodies. The title, corpora, or tubercula quadrigemina, is applied to two pairs of round elevations, situated behind the legs of the brain. They are only found in the mammalia and in man. (PL xi. fig. 1, n, o.) they are joined together by a transverse band (ib. x,) and they communicate with the part called valve of Vieussens (ib. y,) with the bundles that proceed from the medulla oblongata, and with the pretended optic thalami (ib. p.). I have already spoken of the large band, belonging to the optic nerve, that issues from 85 the anterior pair of these bodies. Being in commu- nication with the bundles which come from the pos- terior part of the medulla oblongata, there can be no doubt but the quadrigeminal bodies have their origin lower down in this nervous mass; but as the optic nerves arise from the anterior pair in the mammalia, and as these nerves issue in birds from a couple of ganglions, separated from the general cerebral mass, (for, in birds, they are only united to the bundles that proceed from the medulla oblongata) the analogy and office of these ganglions cannot be called in ques- tion. The destination of the posterior pair of quad- rigeminal bodies is much less obvious. M. Serres* thinks that the bigeminal tubercles of fishes, reptiles, and birds, and the quadrigeminal bod- ies of mammiferous animals and man, are the same mass, destined, in all, to originate the optic nerves, and that the division into two pairs happens merely from a transverse furrow, which, as it runs more or less forwards or backwards, equalizes them, or causes in one case the anterior, in another the posterior pair to predominate. The posterior are intimately connected with the anterior tubercles, it is true ; but there is a white band which issues from the anterior pair, joins a small collection of gray substance, called corpus gen- iculatum externum (pi. viii. fig. 1, q.), is thereby in- creased in size, and then continues its course into the optic nerve ; in like manner there runs a band from the posterior pair, which unites with a mass of * Anatomie du Cerveau ; Preface. Rapport de M. Cuvier. I 86 gray substance, entitled corpus geniculatum internum (pi. xi. fig. 1, r.), and gaining, consequently, in size, afterwards dips under the optic nerve, and is contin- ued on towards the middle cerebral lobe. This structure proves, at the least, that the anterior and posterior pairs of the quadrigeminal bodies are no parts of one and the same nervous mass. M. Serres also fancies that the corpora quadri- gemina serve as a basis, according to which the other parts of the encephalon are determined (' les tuber- cles quadrigeminaux servent de base d la determination des autres parties de Vencephale) ;' and he investi- gates their relations with many particular cerebral parts. His assumption seems to me as incorrect and untenable as the one I have just examined, accord- ing to which the quadrigeminal bodies are parts of one mass similar to the bigeminal tubercles of birds and reptiles. ' The quadrigeminal tubercles,' says M. Serres, are developed, in all the classes, and in every fami- ly of each class, in a direct ratio, as are the optic nerves and the eyes. Fishes have the largest quad- rigeminal tubercles, and the most remarkable eyes and optic nerves. The very considerable size of their quadrigeminal bodies, indeed, has led anatom- ists, up to the present time, into the error of suppos- ing them to be the hemispheres of the brain. After fishes come reptiles, then birds, next, among mam- miferous animals, the rodentia, and in succession, the ruminantia, the carnivora, the quadrumana, and man.' 87 I have already shown, that in fishes generally, the ganglions called optic, are disproportionate in size to the nerves of vision ; and I have said that part of these masses was, probably, destined to other func- tions. The optic nerve of the carp (pi. ii. fig. 4, 20) is smaller than that of the roach (pi. ii. fig. 11, 20), but the so styled optic ganglions (ib. n.) exist in these fishes in an inverse proportion. ' The spinal marrow and the corpora quadri- gemina,' says M. Serres in another place, ' are so rigorously developed in the ratio of each other, that the size of the first being given in any class or in any of its families, the volume of the latter may be determined with precision.' But the bigeminal tubercles in the carp (pi. ii. fig. 5, n.) are much larger, in proportion to the spinal cord, than in the eel (pi. ii. fig. 1) and the roach (pi. ii. fig. 11). M. Serres, himself, has given repre- sentations of the optic apparatus in the cassowary, ostrich, and other birds, much larger in proportion to the spinal cord, than it is in the many mammifer- ous animals whose brains he has figured ; and the disproportion between the development of the quad- rigeminal bodies and spinal cord, is even greater in the dolphins and porpoises, than in the ox, camel, and horse. The most cursory glance over the physiology of living beings also shows the utter erroneousness of M. Serres's position. Powers of voluntary motion and of touch never bear any direct proportion to the fac- ulty of vision. The mole is, certainly, far more re- 88 markable for its muscular strength than for its eye- sight, and the owl for its powers of vision than for its bodily vigor. I shall discuss the several relations which M. Serres believes he has found between the quadrigeminal bodies and other parts of the nervous system, as I treat of these in succession. M. Bailly, in his Memoir on the Comparative Anat- omy of the Nervous System in the four classes of Ver- tebral Animals, maintains that the corpora quadri- gemina anteriora etposteriora, the corpora geniculata externa et interna, are mere parts of the optic lobe of inferior classes. He speaks of the unfolding of the quadrigeminal bodies in fishes, and of two systems of fibres very different from each other : the one ex- terior, and belonging to the optic nerves'; the other interior, and being the expansion of a cord of the medulla oblongata. ' In fishes and reptiles,' says he, ' the internal have a much greater relative develop- ment than the external fibres; in mammiferous ani- mals, the external fibres alone remain ; the internal exist as mere rudiments.' Dr. Gall* also says he is ' convinced that the pos- terior pair of the corpora quadrigemina is a ganglion, for the purpose of reinforcing or perfecting the optic nerve.' He adds — < The modes in which these two pairs assist the function of vision must differ, for they occur in various proportions to each other, in the different species of animals ; in some, indeed, the f Sur les Fonctions du Cerveau.-Ed. in 8vo. Vol. vi. p. 55. 89 posterior two are scarcely perceptible, or are even entirely wanting, although vision be perfect, as hap- pens in the case of birds.' This diversity of opinion is to be accounted for, by recalling to mind the delicacy of the cerebral or- ganization, and the intimate connexion of the parts with each other. When anatomists observe one or two parts connected together, they very commonly conceive the one to be derived from the other. By- and-by I shall treat, in a separate section, of the com- munications of the nervous masses, and of the impor- tance of this arrangement. Meantime, I shall pass my opinions respecting the quadrigeminal bodies in re- view before my reader. The mammalia atone have quadrigeminal bodies. Both pairs, however, have not, I conceive, similar offices; for there is no proportion between them indis- criminately, nor the bundles of fibres which issue in different directions from each. The fibres of the anterior pair, as I have said, join the optic nerves, those of the posterior plunge under the optic nerves, and are lost on the middle lobes of the brain. The optic nerve communicates, by means of superficial bands, with the posterior pair of the quadrigeminal bodies, with the internal and external geniculated bodies, with the middle and anterior cerebral lobes, and with the mass called tuber cinereum. Reptiles and birds have only one pair of rounded tubercles, before and by the sides of the cerebellum. (PL iii. fig. 2, 3, 4, 5, 7, 10 and 11, n.) These are readily seen, by throwing back the cerebellum. On examining their structure, they are found, in the 12 90 first place, to be hollow (pi. iii. fig. 9, side B. n.), and to detach a superficial layer that communicates with the medulla oblongata behind, and with the optic nerve and base of the brain before; and, in the second place, to be connected by their lower parts with the optic nerves and the cerebral crura or legs. This structure of the optic ganglions in birds and reptiles, corresponds to that of the anterior pair of the quadrigeminal and external geniculated bodies in mammiferous animals, as in them the one and super- ficial layer of the anterior pair is continued into the op- tic nerve, whilst the other and deeper is connected with the crura of the brain. In fishes, the optic nerves always communicate with the basis of the pair of tubercles that succeeds the cerebellum, and this pair is connected with the medulla oblongata ; but it and the optic nerves have not, mutually, any regular or fixed proportion, whilst the optic nerves and the rounded tubercles that lie immediately behind their crossing, are constantly developed in the ratio of each other. The optic nerve, in fishes, moreover, communicates with the basis of the cerebral masses that come after the cerebellum, precisely as it is connected in the mammalia with the anterior and middle lobes of the brain. In proportion, therefore, as the cerebral masses and fibrous bundles, or their successive additions, diminish in number through the four classes of verte- bral animals, the primary optic ganglions approach each other, and lie between or among such cere- bral parts as still exist; but as the brain gets complicated, and vision exerts an important influence 91 upon its functions, the primary optic ganglions lie backwards, in order that the apparatus of vision may, conveniently, be brought into communication with the cerebral parts whose functions it especially aids. Of the Olfactory Nerve, — 1st pair of Willis. — Eth- moidal Nerve. Very different opinions have been and are still en- tertained by anatomists in regard to the origin of the nerve of smell. Some of the moderns have described it as arising from the masses called striated bodies; but there is no proportion, whatever, between them and the nerve; and further, porpoises and dolphins have the striated bodies, but no olfactory nerves. The nerves of smell also exist in many acepha- lous monsters, whose striated bodies are, of course, wanting. The olfactory nerve, in the human kind, has three roots ; of these, the interior (pi. vi. 21) is the shortest, but broadest, and the exterior the longest (ib. 18), for it extends to the bottom of the fissure of Sylvius. These different roots are, as it were, impacted in the cerebral substance; they approach by degrees, and having met, advance in the form of a single nervous trunk. In man, the nerve parts from the anterior lobe at the place where the convolutions commence, and runs along the cleft formed between the inner- most of the anterior and inferior of these, accompa- nied throughout its whole course by a very distinct 92 streak of cineritious substance. Immediately above the cribriform plate of the ethmoid bone, it encoun- ters a considerable quantity of very soft gray sub- stance, with which it forms a sort of bulb. (PL vi. fig. 1, 23.) The nerve, here, gains a mighty increase in size, and passing by numerous filaments through the cribriform plate of the ethmoid bone, it is lost upon the lining membrane of the nose. The olfactory nerve of monkies (pi. v. fig. 3), and of seals, resembles that of man very nearly. In the class mammalia, generally (pi. iv. fig. 2) a great many nervous fibres may be seen arising from the anterior part of the middle cerebral lobe : these join the fibres that spring from the inferior surface of the anterior convolutions, and compose a broad and rounded band, which, remaining attached to the anterior lobe, runs slightly inwards until it arrives at the ethmoid bone, when precisely, as in man, it meets a large mass of gray substance (pi. iv. fig. 2, 3, and 4, 23), and in- creases in size so much, that after its exit by the eth- moidal holes, it suffices to cover the entire surfaces of the large superior spongy bones. The bulb that is formed over the ethmoid bone, if it be incised, or have a piece taken out, will be found to be hollow. Its internal white layer in the lower animals communicates immediately with the anterior cavity of the brain, so that by blowing into the bulb of the olfactory nerve, the air will penetrate and inflate the lateral ventricles. Scemmerring says, that the olfactory nerve of the human embryo, at an early period, is also hollow, and that air blown into it reaches the cavities of the brain. The same ex- 93 periment will, occasionally, though very rarely suc- ceed in the adult. When we observe the olfactory nerve so very large in the mammalia, whilst the mass of anterior convolutions is but inconsiderable, and, on the other hand, the nerve in the human kind so small and surrounded by the thick masses of the anterior lobe, we may conceive why the experiment should succeed so readily in animals, and be so rarely prac- ticable in man. The olfactory nerve, it may be almost unnecessary to state, is proportionate in size to the extent of ex- ternal apparatus over which it is distributed. In birds the nerve of smell is detached from the anterior and inner part of the front lobe, but its fibres are distinct from those of the brain ; one of its bands, too, which may be compared with the external root of the same nerve in man, runs towards the fissure of Sylvius and the middle lobe. This band, howev- er, is not equally apparent in all birds. It is still less distinct in reptiles. In fishes the olfactory nerve arises by two very distinct roots; certain fibres of great delicacy bring it into communication with the foremost cerebral ganglions, and others of a firmer texture and whiter color connect it with the longitudinal band, which, in these animals, lies in the middle line between the various ganglions, and communicates with the me- dulla oblongata. (PL ii. fig. 9 and 13.) Some anatomists have considered the entire mass of the anterior cerebral ganglion in the skate (pi. ii. fig. 3, 1,2, 3), and all the three pairs of ganglions in the eel (pi. ii. fig. 1, 1, 2, 3), as destined toorigi* 94 nate the olfactory nerve. But the error here com- mitted is proclaimed by the fact of the origins being always in proportion to the nerves themselves, and there being none whatever between the masses men- tioned and the olfactory nerves of fishes. In regard to these ganglions, therefore, that which has been stated respecting those of vision must be repeated; the olfactory nerve is in communication with cere- bral parts, destined to affective and intellectual func- tions. 95 Section IV. Of the best Method of dissecting the Brain. Before Dr. Gall and I began our researches on the structure of the brain, anatomists, in their dissections and descriptions, had no other object in view than to know the forms of the whole, or of its particular masses, the color, connexion, and consistency, of its individual parts. To attain their end, they were in the habit of cutting clown the brain by slices, and examining and noting the appearances presented by each in succession, until they arrived at the base. ' The most accredited method,' says M. Cuvier,* ' of the schools, and usually recommended in books of anatomy, is to take away successive slices of the organ (the brain), and to remark the appearances offered by- each. This is the easiest in practice for the demon- stration, but it is the most difficult for the imagination. The true relations of parts, which are always seen cut across, escape not the pupil alone, but the master himself.' Willisf was the first who objected to the practice of considering, as distinct parts, all the forms acci- * Rapport des Commissaires de Plnstitute de France, on our Me- moir entitled ' Recherches sur le Sysieme Nerveux en General, et sur le Cerveau en Particulier.' f Cerebri Anatomia. 96 dentally produced by such a mode of dissection. He himself viewed the cerebral parts in their connexions. He says, too, that the anatomical demonstration of the brain should be begun at the basis ; by basis, however, let me observe, he understood the striated bodies and thalami. Ascending from these to the superior parts, and returning on the inferior in succession, his atten- tion was confined to the larger masses, which he de- signates by names that indicate physical qualities only. 'From the striated bodies,' for example, he says, ' the legs of the medulla oblongata are pro- longed: remaining apart for a short way, they then approach and get blended into a common stalk, composed, as it were, of two peduncles or stems.' As the Committee of the French Institute have conceived themselves authorized to assimilate the method of dissecting the brain, described in our Me- moir, with the plan pursued by Varolius and Vieus- sens, and have interpreted these authors in a way which their language will not bear, I hope it will not be found amiss, if I extract a few passages from our Memoir, following them by some observations on the report. 'The brain,' say the Committee, 'is attacked from below ; the medulla oblongata is pursued across the bridge of Varolius, through the thalami of the optic nerves, and the striated bodies, when its fibres expand and compose the hemispheres. The hemis- pheres, also, if we choose, may, by tearing their lat- eral attachments to the crura cerebri, be unfolded, 97 the medulla oblongata and cerebellum be split longi- tudinally, and each half of the former shown as a sort of stem implanted into the hemisphere of its own side, like the stalk of a mushroom into its cap.' They add, ' It is probable that this method would have had more vogue, were it not expressed in a rude drawing by Varolius, and had not the work of Vieus- sens remained, it would be difficult to say wherefore, in a sort of discredit, which it by no means de- serves.' In reply to this w7e cite the following passages, from the works of the two authors mentioned above.* ' The generality of anatomists,' says Varolius, ' think the spinal marrow begins at the occipital hole only ; I can bring proof to the contrary. It arises on the one hand below the ventricles of the brain, and on the other from the middle and inferior part of the cerebral basis. In the same manner as the brain, from out its substance, first, produces that considera- ble trunk, the spinal marrow, from which the occular nerves soon arise; in the same manner the cerebel- lum pushes from itself a considerable process, which I call bridge of the cerebellum, out of which the auditory nerves then issue/I* 'That the sense of touch may inhere in all parts, and that all parts may convey images of objects, cognized by touch, to the primary sensorium, there are four roots issuing from the brain and cerebellum to form a considerable trunk, * Constantii Varolii Anatomicse, sive de Resolutione Corporis Hu- mani Libri Quatuor. Frankforti, 1591; and Vieussenius, Neurogra- phia Universalis. f Varolius, p. 26. 13 98 the spinal marrow, from which nerves are sentoffand distributed to every part of the body .'* ' For my part, seeing that there were several cerebral organs situated about the base of the head, and that the brain by its weight (especially in the dead) compressed these against the skull, I deemed the ordinary mode of dissection liable to many inconveniencies. This is the reason why I am in the habit of commencing the dissection at the opposite part of the head ; that is to say, at the basis of the brain, and by so doing, each of its organs is so clearly exhibited, that it seems as if nothing further could be desired. This method, however, which differs from the usual one, is also very difficult.'f Let any one read Varolius's letter to Mercurialis, and he will be convinced, from his entire description, that he confined himself to the various forms and appearances visible in the brain and cerebellum ; that he did no more than attack the brain mechanically, turning and returning it without order or method, going from the cerebellum to the optic and olfactory nerves, and from the optic and ol- factory nerves coming back to the cerebellum. Let me add, that Varolius himself says, that the mass he calls spinal marrow is comprised between the annu- lar protuberance and the cerebral hemispheres ; and further, that he continually speaks of the spinal cord as a production of the brain. What the Committee of the French Institute make Varolius say, conse- quently, is not to be found in his works. Let us now turn to and review the method of dis- * Varolius, p. 36. f Ibid. p. 140. 99 section practised by Vieussens, which, according to the Committee of the French Institute, is '■the same that Varolius employed, but with greater order and detail.' In his first thirteen plates he shows nothing but sections of the braiii from above downwards. He begins his demonstration with the convex partof the hemispheres, and then passes to the corpus cal- losum. The better to expose this, he cuts off the entire superimposed hemispheres by a horizontal sweep, and then, by properly trimming the mass that is left, he forms, what he calls, the centrum orale, in which he concentrates all the medullary fibres that, according to him, arise from the cortical substance of the brain, and from which he makes nervous fibres descend to every part of the body. He then passes on to the transparent partition (valvula Vieussenii,) that has since gone by his name, to the fornix, to the choroid plexus, to the nates, to the testes, &c. &c. ' We have,' he says, in one place expressly, ' ex- plained in a clear and complete manner, all that concerns the superior part of the brain and medulla oblongata ; we have also examined the cerebellum externally and internally; we have only then, fol- lowing the order of dissection which we have adopted, to examine what is found without and within the basis of the brain, properly so called, and the spinal marrow.' ' After the exact explanation,' he proceeds, < of all that is to be seen on the upper part of the brain and spinal marrow, or that belongs to the cerebellum, in order to find with ease, and to describe with care 100 that which is found at the basis of the brain, properly so called, and of the spinal marrow, we take away the cerebellum by cutting its peduncles transversely, and turn over the brain, freed from its convex parts by partial sections, and then we show the divided trunks of the anterior arteries of the base of the brain — the ten pairs of nerves — the infundibulum — the two white prominences situated near the in- fundibulum — the two processes of the cerebellum towards the medulla oblongata, which run into the major annular protuberance of Willis — the pyrami- dal bodies — the olivary bodies—and the spinal nerves which join the par vagum.' It was always from his oval centre that Vieussens began his sections and descriptions of the brain. His principles, indeed, did not permit him to follow any other method of demonstration. In our answer to the Committee of the Institute, Dr. Gall and I have gone more deeply into details; but the passages cited above will suffice to show that the methods of Varolius and Vieussens are directly opposed to our manner of dissecting and considering the brain and its parts. Vieussens, in deriving all the nervous fibres from his oval centre, proves him- self to have had no idea of the successive reinforce- ment of the cerebral masses. I may, indeed, say generally, that an examination of all the anatomical works published before our time, and an inquiry into the various modes in which the brain has been dis- sected, whether in public or in private schools, will not fail to convince every candid mind that there is 101 not even a hint at the anatomico-physiological views which we have given to the world. These views some modern anatomists have adopted, but we still advance our claim of right to be considered as the discoverers and introducers of a new method of dis- secting the brain — as the first demonstrators of the anatomy of its masses in harmony with their physi- ology. What, then, is our mode of investigating the struc- ture of the various cerebral masses ? I have already shown (in the preceding section.) that we consider the nerves commonly entitled cerebral, as indepen- dent of each other, and that we regard the masses of the cerebellum, and brain, properly so called, as ad- ded to the nerves of the five senses and of voluntary motion. This point of doctrine established, we view the brain not as an unit or single organ, but as an as- semblage of particular apparatuses destined to special and determinate functions, after the manner of the nerves of the external senses. To this it may be said, that several anatomists have spoken of many peculiar parts, that they have even designated these by appropriate names, conse- quently, that our ideas on the plurality of apparatus are not new. There is no doubt whatever, but that all anatomists have recognized distinct parts in the brain, and giv- en them names according to their physical qualities. They have found hemispheres, convolutions, cavities, striated bodies, pea-shaped bodies, stalks or legs of the brain and cerebellum, writing pens, rams'-horns, 102 semicircular tape-worms, pyramidal and olive-like bodies, &c. &c. Now we, in showing that the in- dividual masses, so named, do by no means consti- tute special apparatuses, performing peculiar func- tions, differ from all the anatomists who have gone before us. We were, also, the first to prove the relative proportions that exist between several of the cerebral masses, and to examine them in their mu- tual relations. If I continue to make use of the me- chanical nomenclature, to speak of parts in particu- lar, which can no longer be considered as special apparatuses, it is only for the sake of being more readily understood. My connected description will show what masses I look upon as peculiar organs. Our physiological views do not, it must be evident, allow us to go on cutting the brain into slices : this procedure, indeed, ought rather to be entitled a de- struction, than an anatomical demonstration of the cerebral structure; it is precisely as though one should pretend to dissect a leg or an arm, by slicing down those members transversely, or to show the structure of the thoracic and abdominal viscera, by treating the trunk in a similar manner, and giving names to the appearances exposed after each succes- sive slice. We commence our dissection at the place where the proper cerebral masses are added to the nervous parts already described ; we trace them in their continuations, and in their mutual connexions, and in the connexions they maintain with the nerves of the five senses and of voluntary motion ; in short, we proceed in the dissection of the brain in a man- 103 ner precisely analogous to that which is followed in the anatomical demonstration of the other parts of the body. Besides the above general anatomical principle as regards procedure, it is important to know that on account of their extremely delicate organization, the structure of several cerebral parts may be more easily and clearly exposed by means of scraping than by cutting. This is the reason why I frequently prefer the handle to the blade of the scalpel, for removing parts that cover those whose course I would show, — for instance, the passage of the pyramidal bodies across the annular protuberance — the continuation of the anterior commissure through the striated bodies into the middle lobes of the brain, and of the anterior pillars of the fornix, onwards to the mammillary bodies and interior of the thalami. The brain should be removed from the cranium, care being taken not to tear the crura at the superior edge of the annular protuberance, (an accident that is very apt to occur,) nor to injure the medulla ob- longata at the lower edge of the same part, and to cut the spinal mass so low down as to obtain, besides the entire medulla oblongata, the upper part of the true spinal cord. The brain thus freed from the skull, is then to be put into a plate, with the basis uppermost. The cerebellum and medulla oblongata having lost the support of the bone, now fall back- wards. (PL vi. fig. I.) In this position, all the appearances presented by the base of the brain are visible. Having considered the cranial nerves in the manner described in the preceding section, the struc- 104 ture of the true cerebral masses is to be examined, commencing with that of the cerebellum. As I treat of the several parts, 1 shall always indicate the pro- cedure that appears to me the most convenient for exhibiting their anatomy.* *The method of dissecting the brain which M. Laurencet of Lyons proposes, seems founded on imaginary notions, rather than on the ob- servance of nature and fact. According to him, the nervous system is like two trees reversed, the branches of the one being continuous with the roots of the other, or after the manner of the sanguiferous system. The spinal cord, he says, consists of four bundles, which in the medulla oblongata, are the anterior and posterior pyramids. The anterior, after their decussation, he supposes to continue across the pons Varolii, the crura cerebri and corpora striata, towards the corpus callosum and the convolutions, from thence to the fornix, to the thalami, corpora quad- rigemina, cerebellum and posterior pyramids. The number of nervous fibres is assumed to be every where the same ; there are only bulgings and contractions in succession. M. Laurencet cuts the parts, and then tells us how they are formed. 105 Section V. Of the Cerebellum. To avoid all risk of confusion, I repeat once more that I separate the nervous mass of the spine and the cranial nerves from the brain, and confine this last appellation to the entire nervous mass, added to the nerves of the external senses and of voluntary mo- tion, I also repeat that the first anatomical principle of the nervous system, generally, applies to the brain in particular, that is to say, this mass is not a simple unit, but a collection of many peculiar instru- ments. As this proposition is of great importance, I shall examine it here at some length. It is to be es- tablished by anatomy, physiology, and pathology. The physiological and pathological proofs of its truth, are contained in the second section of my Work on Phrenology, wherein I treat of the plurality of the organs. In this place, consequently, I shall confine myself to illustrative anatomical considerations. That the cerebral parts are more or less numerous in different tribes of animals, is a fact which cannot be gainsayed. Many writers, among others, Dr. Gall,* say that the faculties of animals are multiplied in proportion as their brains are complicated. Were * Anat. et Phys. du Cerveau, t. iii. p. 364. 14 106 this remark universally correct, it would serve as a positive proof of the brain's being an assemblage of organs. But without reckoning the difficulty, not to say the impossibility of determining, anatomically, even in birds and mammiferous animals, the constitu- ent parts of the brain, and admitting that as true which mechanical anatomy demonstrates, viz. :— that the brain is made up of a greater or smaller number of bundles, it must still be observed that each partic- ular bundle cannot, legitimately, be assumed as com- posing a peculiar organ. There are several cerebral masses which, although more or less compound, do not, therefore, cease to be mere units. Take the cerebellum as an example. This is extremely simple in fishes, and very complicated in man, nevertheless it is but a single instrument in both. The same law applies to several other cerebral parts, which, although exceedingly complex, only compose the in- strument of a single function. Thus the first fact showing the structure to be more or less complicated, is no satisfactory or conclusive evidence as to the plurality of the cerebral organs—this induction is still only problematical. Dr. Gal! derives another anatomical proof of the principle under discussion, from the analogy that sub- sists between the organization of the brain and that of the other nervous systems. This analogy, how- ever, is very limited. The spinal cord affords no ex- ample of it. Although composed of many parts, or numerous pairs of nerves, its functions are but repe- titions of two of different kinds : viz., sensation and 107 motion. But the particular organs of the brain must be as distinct as the acoustic, optic, and olfactory nerves. A better anatomical illustration follows from the fact of all parts of the brain not being developed si- multaneously, and of their volumes severally bearing no regular proportion to each other. The size of the cerebellum, for instance, is not in any direct ratio to that of the brain, neither are the three lobes of the cerebral hemispheres proportionate to each other. The same law applies in regard to all the in- dividual parts of these lobes. These proofs, founded on the non-simultaneous development and disproportionate volume of the in- dividual portions of the encephalon, are strengthened by facts, which show that the cerebral parts may severally be wanting. M. Jadelot was so kind as to show Dr. Gall and me an hydrocephalic child, in the Hdpital des Enfants Malades, at Paris, many of the superior convolutions of both hemispheres of whose brain were wanting, so that there was a hole com- municating on each side with the lateral ventricles. The edges of these holes were smooth, and all the appearances bespoke a congenate or primary defect of organization. The brain, of which a drawing is given in pi. v. fig. 5 and 6, belonged to a girl, who died, aged seventeen, and was idiotic from birth. She'died in the asylum at Cork. Dr. Abell, of that town, and Dr. Cheyne, of Dublin, had the goodness to send me the natural skull, and casts, in plaster, of the brain and bust. A comparison of this brain with 108 one of a healthy and well-constituted individual (pi. vi. fig. 1 and 2), will show its anterior lobes to be exceedingly deficient, and the convolutions that com- monly exist in the upper region of the forehead to be wanting altogether. It is even less complicated, and more poorly developed, especially anteriorly, than the brain of the ourang-outang. (PL v. fig. 3 and 4.) Mr. Stanley, of London, preserves a similar idiotic brain in spirits. The anatomical evidence, from the want of pro- portion among, and the non-simultaneous develop- ment and entire absence of, the cerebral parts, although plausible, is not, however, decisive in prov- ing the plurality of the organs. The testimony these facts supply only becomes conclusive, when they are united to physiology. Alone, they do not prove that the functions of the parts, whose development is neither stimultaneous nor proportionate, and which, individually, may be wanting, are dissimilar. — The branches of a tree shoot in succession, yet all bear the same fruit. But those cerebral parts are indu- bitably the same, however dissimilar in physical ap- pearance, if like functions appear with their pres- ence, increase with their growth, are vigorous in proportion to their masses, and wanting with their absence. Cerebral parts, on the other hand, differ if like functions do not appear with their development, be not manifested in vigor corresponding to their vol- ume, and exist or not independently of their presence or absence. Certain it is, therefore, that how important soever it may be to classify the cerebral organs, anatomy 109 alone would never enable us to attain such a con- summation. The aid of physiology is indispensably requisite. Now, Dr. Gall and I claim the merit of having been the first to compare the relations between the development of different cerebral parts and pecu- liar functions ; and our physiological anatomy of the brain proves, that the parts indicated in books of de- scriptive anatomy as distinct masses, such, for in- stance, as those styled pons or bridge, pyramidal and olive-like bodies, thalami, mammiliary bodies, callous or hard body, &c. &c, do not constitute particular organs. Some anatomists have expressed doubts as to the possibility of proving the presence or absence of indi- vidual parts in the human brain, especially in the hemispheres and their convolutions ; because, say they, the physical appearance of these is not invaria- ble. But, provided essentials be not confounded with modifications, the very reverse of the above as- sumption may easily be proved. The lobes are always to be distinguished from one another, and cer- tain convolutions from others, with the same certainty as the annular protuberance is to be discriminated from the crura of the brain, the quadrigeminal from the mammiliary, and the pyramidal from the restiform or olive-like bodies. The general form and direction of the convolutions, even of the human brain in its complication, are, in fact, remarkably regular. Thus, the transverse convolutions of the superior lateral and middle parts of the hemispheres are never found run- ning in any other direction, never longitudinally, 110 for example. Those that lie longitudinally again as they do under the squamous suture, behind the temporal bone, and on either side of the ol- factory nerve, are never met with disposed trans- versely. ' Show Gall,' says Dr. Rudolphi,* ' the organs of theft, of murder, and of the religious sentiment sep- arated from the cerebral mass, and be sure he would not know them.' Dr. Gali,f in his reply to this, con- tents himself with saying, ' Show M. Rudolphi mor- sels of the spinal marrow or medulla oblongata, and be sure he would not know them ; yet are the spinal marrow and medulla oblongata proved to be aggre- gates of different nerves.' This answer of Dr. Gall does not satisfy me. In the first place, I have shown the brain to be composed of many parts, whose func- tions are essentially different, whilst all the portions of the spinal cord have similar offices. Dr. Gall's reply, therefore, is simply evasive. But, for my part, I will accept M. Rudolphi's proposition direct- ly ; for I maintain that he who has studied the forms of the peripheral expansions of the cerebral organs, will always be able to distinguish, in man, the organ of acquisitiveness from that of destructiveness, and that of veneration from either, (the organs of theft, murder, and the sentiment of religion, in M. Rudol- phi's nomenclature,) as easily as an ordinary ob- server will the olfactory from the optic nerve. I am ready at any time, personally, to verify the above statement. * Physiologie, ii. Band, Berlin, 1823. t Sur les Fonctions du Cerveau, torn. vi. p. 138. Ill However, I still admit, that the convolutions form- ing parts of any particular apparatus, present many modifications in reference to size and number of an- fractuosities. Such modifications occur, not only in the brains of different individuals, but even in the two hemispheres of the same brain. Variety, how- ever, need not be confounded with essential config- uration. I have remarked, that the organs which are best nourished, and most largely developed, have generally the smallest number of anfractu- osities. The importance of classing the cerebral organs is, as I have said, evident. Researches to this end in- terest the anatomist, the physiologist, and, above all, the practical physician, on account of the brain's in- fluence on the vegetative functions, on the origin, duration, character, and cure of a long list of diseas- es, especially of such as depend on moral causes. To render such inquiries complete, they must be ex- tended into comparative anatomy, always in the view of proving the brain to be an assemblage of or- gans, destined to dissimilar functions, mutually in relation, severally, liable to disease, and likewise to reciprocal derangement. To compare the spinal cord, and even the cranial nerves, in the different classes of vertebral animals, is by no means a very arduous task. But to do the like in regard to the brain is one of extreme difficul- ty. Anatomists commonly set out with the human brain in their eye as a type of comparison ; this they consider as an unit having two hemispheres, a cor- pus callosum, an anterior, middle, and posterior com- 112 missure, an infundibulum, fornix, feet of a hippocam- pus, mammiliary bodies, striated bodies, optic thala- mi, a semicircular tenia or tape-worm, quadrigeminal bodies, crura or legs, a valve of Vieussens, a pons, bridge, or annular protuberance, a cerebellum, having also crura or legs, a medulla oblongata, pyramidal, olivary, and restiform bodies, four ventricles, an aque- duct of Sylvius, and several other parts; and then they proceed to recognize or deny the existence of parts according to mere physical appearances, especially forms and situations. Such a mode of proceeding, however, is quite in- adequate to establish a system of comparative cere- bral anatomy. The brain, in the first place, is not an unit, but an assemblage of particular apparatuses, that require severally to be specified ; and again, it is certain that the isolated masses, such as they are described in books of anatomy, do not constitute pe- culiar organs but that several of them, indeed, some- times go to the formation of one. The cerebellum is found, either with or without an annular protuber- ance ; the anterior pyramidal bodies are not one or- gan, but consist of parts of many ; they are, in fact, the rudiments of the organs of the intellectual facul- ties. And further, the physical appearance of appa- ratuses which are known to have analogous func- tions, is often exceedingly different. Without know- ing the functions of the cerebral parts, it is, there- fore, impossible to demonstrate either their identity or their difference. What anatomist, unacquainted with the function of smell, would ever have con- 113 eluded that the olfactory nerves of the skate, floun- der, chicken, seal, ox, and man, were analogous masses ? Certainly, similarity of appearance would never have led to the conclusion ; and differences in appearance among the other cerebal masses, are not less remarkable than in the olfactory nerve through- out the four classes of vertebral animals. Thus, I conceive that the comparative anatomy of the brain can neither be itself advanced, nor afford satisfactory conclusions without the aid of physiology. The common and objectionable manner of exam- ining the structure of the encephalon, led anatomists to conclude that they had discovered the same cere- bral masses in the mammalia as in man, and, because the forms of the parts were different, to deny their existence in birds and the inferior classes of animals. In all the lower tribes of creation, they supposed an- other and a different composition of the encephalon. I claim the merit of having been the first to man tain that the analogy or difference of cerebral parts, in different classes, ought to be determined by the com- bined aid of anatomy and physiology. I have no hesitation in saying that the relations of the cerebral masses, as they are indicated by M. Serres in his prize memoir, are very far from being satisfactory replies to the question proposed by the Institute of France. I also think it may not be out of place to state that Baron Cuvier, perpetual secretary to the physical class of the French Institute, in his analysis of the academy's labors for the year 1820, has men- tioned the name of Dr. Gall in reference to two points only, on which M. Serres differs with the Doctor, whilst 15 114 he reports several other important facts and views, discovered by me, and published conjointly with Dr. Gall, as forming part of the memoir of M. Serres; such, for instance, as the relation between the annu- lar protuberance and the lateral parts of the cerebel- lum, and that between the corpus callosum and the cerebral hemispheres. In admitting as an anatomico-physiological princi- ple, that the particular organs of the cerebral functions bear no relative proportion, in the same way as the instruments of the external senses are in no direct ratio one to another, I deny generally, as I have al- ready done particularly, in regard to the spinal cord, the proposition of M. Serres, according to which, ' the tubercula quadrigemina serve as a basis of deter- mination to the other parts of the encephalon.'* The quadrigeminal bodies do, in nowise, bear any direct proportion to the anterior, middle, and posterior lobes of the brain. These masses exist independently of each other, and belong to apparatuses that are totally distinct. The quadrigeminal tubercles are absolute- ly smaller in man and the dog, than in the horse and ox ; but the brain of the animals last mentioned is larger than that of the dog, and smaller than that of man. Each special apparatus must be determined by itself, and by comparison with its particular func- tion. In many fishes there are portions of gray nervous substance to be observed, forming ganglions on the * ' Les tubercules quadrigeminaux servent de base de determination aux autres parties de l'Encephale,' Rapport, &c, p. 67 ; and Serres's Anatomie, &c. vol. 1, Preface. 115 lateral edges of the medulla oblongata. (PL ii. fig. 3, 5, 12, 13, e.) By removing the cerebellum, a gan- glion may, in many species, be seen in the middle line (pi. ii. fig. 13, 43;) this ganglion is, sometimes, naturally exposed. (PL ii. fig. 5, 43.) All these masses pertain to the nerves that issue from them. The nervous mass immediately succeeding these ganglia, is the first cerebral apparatus; it is distin- guished by the name of cerebellum, and exists in all vertebral animals lying on the dorsal surface of the medulla oblongata. Its name is derived from the anatomy of man, in whom the corresponding mass is smaller than the brain, properly so called. This ex- ample, among many others that might be cited, proves how defective that nomenclature of the encephalon is, which is founded on the physical qualities of the hu- man brain. Is it not astonishing that anatomists, who deny to fishes a cereberum or brain, should still acknowledge them possessed of a cerebellum or lit- tle brain ? Let me, therefore, repeat, that a good nomenclature should have for its basis the nature of the functions performed by the particular instruments. My only reasons, as I have said already, for continu- ing to use the old and faulty names, is to make my- self understood more readily. The cerebellum or organ of amativeness, is com- plicated in different degrees in the four classes of vertebral animals ; its form and its volume vary ex- ceedingly, but it regularly communicates posteriorly with the nervous mass of the spine on either side, and anteriorly with the bigeminal or quadrigeminal bodies. 116 'To acquire accurate notions of the cerebellum in the superior classes,' says M. Cuvier, ' according to M. Serres, they must, in the first instance, be taken from fishes. In these animals, this organ is formed of two very distinct parts—a middle lobule deriving its roots from the ventricle of the quadrigeminal tu- bercles, and two lateral portions coming from the restiform bodies; the two parts are insulated and disjunct in the whole of the class pisces, a circum- stance that has occasioned them to be mistaken.'* Now this fact is not, by any means, so general as M. Serres would have us suppose. What are his reasons, let me ask, in the first place, for classing the ganglion I have just pointed out as situated in the fourth ventricle (pi. ii. fig. 5 and 13, 43,) along with the cerebellum ? — He can have none. And again, in the eel (pi. ii. fig 1) —in the cod (pi. ii. fig. 2) — in the flounder (pi, ii. fig. 7) — in the roach (ib. fig. 11,) and many others, the surface of the cere- bellum is quite smooth. In the skate, on the contrary, it is evidently composed of several ramifications, (pi. ii. fig. 3.) In fishes, generally, there is a bundle which, with its fellow of the opposite side, forms a hollow mass stretched above the fourth ventricle, and covered on * 'Pour avoir des notions exactes sur les cervelets des classes supe- rieures d'apres le Memoire de M. Serres, il faut d'abord les emprunter aux poissons. —Chez les poissons cet organe est forme de deux par- ties tres distinctes: d'un lobule median, prenant ses racines dans le ven- tricute des tubercutes quadrigeminaux, et de feuillets lateraux prove- nant du corps restiforme : les deux parties sont isolees, disjointes dans toute la classe des poissons ce qui les avait fait meconnaitre.'—Rapport des Travaux de la Classe Physique pendant VAnnie 1820, p. 67. 117 its peripheral surface with gray substance. It is, for the most part, loose at one extremity only ; it has ei- ther a pointed, a rounded, or a flattened form, and is most commonly turned towards the back. In the skate, however, it has two loose extremities, the one pointing forwards, the other backwards. Reptiles, in general, have a cerebellum, composed of two parts, which are hollow, superficially smooth, and in communication with each side of the me- dulla oblongata. In some of the class, it is extreme- ly small, as in the toad and frog (pi. iii. fig. 2,) which, in this respect, resemble the sturgeon among fishes : in other reptiles, however, and of the number is the crocodile, the cerebellum, as in the skate and shark, is furrowed on the surface, and bears marks of a more complicated structure. The ramified and lamellar structure of the cere- bellum (pi. iii. fig. 5, 6, 7, 9, 10, and 11,) and its division into median and lateral portions, become very evident and regular in birds and mammiferous animals. In birds, (pi. iii. fig. 5, 7, 10, and 11,) the middle or primary portion is large compared with the lateral parts. These, indeed, are scarcely evolved in the class aves; they, however, become ever more remarkable in size and number of ramifications, in proportion as we mount from the lowest up to the highest of the mammiferous tribes and reach man. In the foetus, the cerebellum, even of those animals in which it afterwards presents numerous convolu- tions, is always quite smooth. The primary portion of the cerebellum, in all birds, is divided into several branches ; the middle and upper one of these is the 118 most remarkable. Below and in front of the fourth ventricle, in the same class, there occurs a little lo- bule, the volume of which, like that of the lateral parts, is much augmented in the mammalia. These peculiarities of structure prove that oviparous animals, in general, cannot be said to have a simple cerebel- lum. The cerebellum of fishes, of reptiles, and of birds (pi. xi. fig. 3, 62,) is constantly hollow. Its cavity communicates with the fourth ventricle (ib. m,) or space between the cerebellum and medulla oblongata. The cerebellum of the mammalia is, on the other hand, invariably solid ; the fourth ventricle is the only cavity in its vicinity, (PL xi. fig. 1, m.) The anatomical principle laid down in regard to the regularity of proportion, between the cineritious and white substances, and to the occurrence of cineritious matter at the origins of nervous masses, is confirmed by the structure of the cerebellum. At the place of this organ's attachment to the medulla oblongata, there is always an accumulation of pulpy substance to a greater or smaller amount; that is to say, the quantity is great, or small, relatively to the volume of the entire cerebellum. In man it composes an irregularly-shaped mass, toothed or serrated around the edges. This collection of cineritious intermixed with white matter, is described in books of anatomy under various names, such as corpus rhomboideum, corpus dentatum zig-zag, and kernel of the cerebel- lum. I speak of it under the title of ganglion of the cerebellum. 119 ) Vicq d'Azyr believed that the ganglion of the cere- bellum was only to be found in the human kind. But in 1808, conjointly with Dr. Gall, I showed that it exists in the mammalia generally ; * and I now add, that it is very distinct in birds. Whenever the cerebellum is somewhat considerable, it may always be demonstrated. Its small size and pale color were probably the causes of its existence being overlooked. But it is matter of prime importance not to confound the forms assumed, and the lighter or deeper shades of color possessed by the pulpy substance, with its necessary existence. The quantity of cineritious substance at the origin of the cerebellum is in the direct ratio of the entire mass, and not merely of the lateral parts of that or- gan. It is very conspicuous in birds, although the lateral parts of their cerebella be but rudimentary. In man, too, a portion of the ganglion may easily be demonstrated running towards the vermiform process (the primary part) of the cerebellum. From what I have said, it follows, that this gang- lion is not situated in the middle of the cerebellum, but commences where this mass is connected with the medulla oblongata. Vicq d'Azyr commits a capital error in his plate xxxi. fig. 20, in representing the ganglion of the cerebellum as placed so much exter- nally, so near to the anterior edge of the organ to which it belongs, and so far distant from the medulla oblongata. In forming the cerebellum, nature has, in all ani- mals, pursued the same plan. Two bundles con- * Vid. Memoire sur l'Anatomie du Cerveau, &c. 120 stantly bring it into connexion with the two sides of the medulla oblongata ; these are of variable size ; they meet a greater or smaller quantity of gray sub- stance, and proceed strengthened in proportion to the quantity of this substance encountered ; they then regularly compose a primary portion, which in the lowest tribes is smooth superficially, but which, as the scale is mounted in, appears furrowed transverse- ly, or divided into lamellae, and becomes complicated by the addition of lateral masses, laminated in like manner. This lamellar structure is exposed by a ver- tical cut through the cerebellum ; it bears the name of arbor vitae, on account of its supposed resemblance to the foliage of the thuya, or tree of life. (PL viii. and ix. fig. 1 and 2.) Although the human cerebellum be very complica- ted, the elements of a precisely similar formation to that of the lower animals, may without difficulty be traced. One slip from the ganglion forms with its fellow of the opposite side the vermiform process, or primary portion, which, by a cut carried through the middle line, may be seen afterwards dividing com- monly into seven principal parts. (PL vii. fig. 2, and pi. x. fig. 1, and pi. xi. fig. 1, A.) These divide in- to branches, and these again into leafets, differing in each case in number, length, and volume generally. The other slips or bundles that issue from the gang- lion proceed backwards, upwards, downwards, and outwards, and expand into layers, which are disposed horizontally. Those that come from the middle of the ganglion are the longest; the others are succes- sively shorter, as they issue nearer to the commence- 121 ment of the ganglion. (PL viii. fig. 1, pi. ix. 1 and 2, and pi. xi. fig. 1, B.) The peripheral extremities of the bundles thus disposed in lamellae, are, as well as when they ex- pand and form an uninterruptedly smooth surface, covered with a layer of cineritious substance. By a section carried vertically though the middle of the ganglion in the direction of its bundles, eleven principal trunks or branches are commonly exposed. The nearer the cut runs to the middle, or posterior edges, of the cerebellar hemispheres, the greater will be the number of branches discovered, as their quantity will be fewer in proportion as it passes nearer to the mesial line of the body. Two branch- es may frequently be seen intimately united near the base of the ganglion (pi. ix. fig. 2, and pi. xi. fig. 1, B.), and forming, for some little way, a common stalk ; but in other cases they proceed quite distinct- ly from the very beginning. Still greater varieties are to be detected in the interior divisions and sub- divisions, which are unimportant, and require no par- ticular mention. The ganglion of the cerebellum varies considera- bly in form, and this, not only in different species, but even in different individuals of the same kind of animals. Its appearance also changes according to the mode in which it is cut; horizontally incised, it has the figure expressed in pi. viii. fig. 2. B. s. ; ob- liquely, the form represented in pi. xi. fig. 1, B. s. ; and vertically, the shape given in pi. viii. fig. 1, and 16 122 pi. ix. fig. 1 and 2 s. A horizontal cut shows it in its greatest extent. Although the portions or ramifications of the cere- bellum be divided into parallel lamellae, they do not ultimately lie parallel to each other ; each portion thus considered is placed obliquely. Neither are the furrows on the outer surface parallel. (PL vi. fig. 1 and 2. PI. viii. fig. 1, B.) Soemmering has remark- ed, and exposed the error generally committed by anatomists in this matter in their drawings. It is also a mistake to suppose that the furrows of the cerebellum penetrate deeply into its substance. They only do so in the clefts that mark its principal divisions. In the mammiferous class of animals the cerebel- lum is augmented by the addition of a mass, known variously by the names pons Varolii, tuber annulare, or mesolobe. The transverse fibres of this part evi- dently belong to the hemispheres or lateral portions of the cerebellum, to which they bear a marked and regular proportion. (PL viii. fig. 2.) No one can deny to Dr. Gall and me the merit of having first detected the relations that exist between the annular protuberance and cerebellar hemispheres. M. Tiede- mann* says, that we err in deriving the transverse fibres of the annular protuberance from the cineritious substance covering the leafcts of the cerebellum, be- cause these transverse fibres are visible before any division into lamellae can be recognized in the cere- bellum. This reasoning of M. Tiedemann, however, does not seem very conclusive, since the annular * Anatomie du Cerveau dans le Foetus Humain, Nurnberg, 1816. 123 protuberance and cerebellum are developed at the same time. It is, on the other hand, at least certain that M. Tiedemann is himself mistaken, in suppos- ing the transverse fibres of the annular protuberance to come in part, from the corpus dentatum (ganglion of the cerebellum.)* The annular protuberance lies most evidently anteriorly and quite externally to the ganglion of the cerebellum ; its fibres, moreover, may easily be demonstrated, as commencing directly from the lamellae of the hemispheres. (PI. viii. fig. 2.) I, for my part, insist rather on the progressive aug- mentation of the cerebellum in the different classes of animals, than on the successive increase of its in- dividual constituent parts. It appears certain, that the several parts of the cerebellum are not simulta- neously developed ; that some of these are visible at an earlier period than others. But it still remains a point of great difficulty to determine the part which serves as the centre of departure or originator of the others. Are the various portions developed after the manner of the graft of a fruit-tree, or, are there branches thrown off in succession, or, are the rudi- ments of the whole called into being at once, and maturity of growth then acquired by each in succes- sion ? The first supposition, I confess, appears the most probable to myself. It is not unreasonable also to presume, that the fibres of communication, and the fibres of the commissures, or apparatuses of union, appear together, whilst the peculiar apparatus which is to perform a special function acquires the form, vol- ume, and organic condition necessary to this duty by degrees. *Op.cit. p. 107. 124 Although the cerebellum be ever more complicated as we ascend in the scale of beings, it is a fact, that animals do not exhibit faculties in proportion as this mass presents a larger number of lamellae or ramifi- cations. Neither is it found that the intellectual and other general mental powers of individuals of the human kind increase, or are active in the ratio of the cerebellar lamellae, as was once maintained by Mala- carne. Many authors have said, that the cerebellum con- tained, in proportion to its bulk, more cineritious sub- stance than the brain; and, as a consequence of this notion, it came to be regarded as softer than the brain. Both of these assumptions are incorrect. The primary mistake was probably committed from vertical sections having always been employed to expose the internal structure, i. e., the arbor vitae of the cerebellum, whilst horizontal slicing was the method followed in regard to the brain. But let an opposite procedure be adopted ; let the cerebellum be divided horizontally, and the brain vertically, and more,cineritious substance certainly will then appear in the brain than in the cerebellum. The cerebral convolutions again, it is natural to think, will, on account of their mere thickness, seem firmer than the cerebellar leafets ; but careful examination proves that in one case the brain, and in another the cere- bellum, possesses the greatest degree of consistency. Age and fortuitous circumstances, as disease, &c, exert a particular influence in this respect. From what has been said when discussing the nerves of the external senses and voluntary motion, 125 it may almost be unnecessary here to state, that none of them arises from the cerebellum. All the parts of the cerebellum are double, or exist in pairs : its primary portion or vermiform process, is no exception to the law; all its parts, however, are not necessarily symmetrical; the elements compos- ing each side are alike, but the size of the essen- tial bundles, the length and thickness of their branch- es, the number of subdivisions of these, and the form and position of the lamellae vary extremely in different individuals ; and often on both sides of the same cerebellum, the entire mass of one side is not unfrequently more largely developed than that of the other. In their descriptions of the cerebellum, anatomists still make mention of two soft and thin layers, the one of which unites the upper part of the posterior pyramidal bodies with the lower portion of the ver- miform process (the primary or' essential mass.) whilst the other brings the cerebellum into connex- ion with the quadrigeminal tubercles. The latter is commonly known by the name of the valve of Vieussens, or by the singular title of processus a cere- bello ad testes. (PL xi. fig. 1 and 3. y.) Reil styles them the superior and inferior medullary veils. The valve of Vieussens, or layer of communication between the primary portion of the cerebellum and quadrigeminal tubercles, may be distinctly traced through all the four classes of vertebral animals. It increases in size in the ratio of the distance and nervous masses, between the cerebellum and quadrigeminal tubercles. The inferior veil, on the 126 contrary, is but just apparent in birds : in the mam- malia, however, like the superior, it is conspicuous, although varying in size in the different species com- posing the class. The idea of a determinate proportion between the brain and cerebellum is one still very generally en- tertained. Authors on the comparative anatomy of the brain have even drawn up tables of this supposed proportion. 'It is easy,' says M. Cuvier,* ' to as- certain the proportionate weight of the brain and cerebellum, because no variation in health, and no change in the bodily condition, as to obesity or lean- ness, exert any influence on them.' But it is long since Dr. Gall and I showed, that the cerebellum has no regular proportion to the brain. In the adult, a small cerebellum is often met conjoined with a very large brain ; and in other cases, the cerebellum occurs of great size, while the brain is particularly small. M. Chaussier has also observed, that the cerebellum com- posed atone time the sixth, at another the seventh, and at another, and more rarely, the tenth of the weight of the encephalon. In newly-born infants, he found that it was the thirteenth, the fourteenth, the seven- teenth, and, in one instance, no more than the thirtieth part, by weight, of the encephalon. Whoever, indeed, will be at the pains to compare the encephalon of children of two, four, six, and ten, and of young people up to their sixteenth year, will be convinced, that relatively to the brain the cerebellum is at these periods smaller than in adult age. If any exception to the rule be found, it must be regarded as an indi- * Legon's d'Anatomie Comparee, vol. ii. p. 152, 127 vidual peculiarity of organization. Moreover, the ce- rebellum is generally larger in men than in women, and in males than in females of the same kind of animal. Let us now examine some points of M. Serres's Prize Memoir, in relation to the cerebellum. He says,* 'it may appear singular, that the cerebel- lum should not be formed till after the quadrigeminal tubercles ; nevertheless, there is no exception to this fact in any class.' Now this fact will not appear singular, but seem perfectly natural to those who are acquainted with the functions of the apparatus that arises from the quadrigeminal bodies, and with the office of the ce- rebellum. As the optic nerve has to act long before the cerebellum, its organization requires to be com- plete long before that of the cerebellum needs to be perfect. Further, the brain is also developed at a later period than the quadrigeminal bodies ; the cere- bellum consequently presents nothing whatever that is singular in this respect. ' The vermiform process,' says M. Serres in an- other place,! ' comes from the quadrigeminal tuber- cles, whilst the other part, issuing from the restiform bodies, constitutes the hemispheres of the cerebel- lum. The two elements of the cerebellum, (the vermiform process and lateral parts,) also, though united, are still enrirely independent of each other.' These propositions do not to me seem founded in nature. Were we to admit the bigeminal bodies of fishes and reptiles, and the quadrigeminal tubercles » Rapport de PInstitut, 1820, p. 68. t Ibid. p. 68. 128 of the mammalia, as the source of the Vermiform process, or primary portion of the cerebellum, we should then expect some regular proportion in the development of these parts to each other. But M. Serres himself excepts reptiles. 'In all the classes, except that of reptiles,' he says,* ' the median lobe of the cerebellum (processus vermiculaire superieur,) is developed in the direct ratio of the quadrigeminal bodies.' Now this exception is of itself sufficient to refute M. Serres's entire assumption. However, let the cerebellum be compared with the optic tubercles in the sturgeon, in the eel (pi. ii. fig. 1,) flounder (pi. ii. fig. 4,) skate (pi. ii. fig. 3,) barbel (pi. ii. fig. 12,) pigeon, turkey, dog, and other animals, to procure data, by which to estimate the utter erro- neousness of M. Serres's opinions. On dissecting the eerebelliwn of mammiferous animals, the vermi- form process, as well as the other ramifications, gen- erally, will be seen communicating distinctly with the dentated body, or ganglion of this organ. Lastly, and still further, to expose this error relative to the origin of the primary portion of the cerebellum, let us recur to pathological anatomy, as well to the cases produced accidentally or by disease, as to those creat- ed intentionally, or bv mutilations. Atrophy of the optic nerves, caused in any way, is well known to extend to the anterior pair of quadrigeminal bodies; no one, however, has yet imagined that it was contin- ued on to the median lobe, or primary portion of the cerebellum. The optic tubercles and the vermiform process, therefore, exist independently of each other ; * Rapport de l'Institut, 1820, p. 68. 129 they are connected, only that they may exert a mu- tual influence. It is not the same in regard to the median lobe and the lateral parts of the cerebellum. True it is, that these two masses are not necessarily proportionate to each other ; this fact, however, does not prove each entirely independent of the other, as M. Serres has presumed.* 1 take his own manner of viewing the matter in illustration ; he regards the bigeminal tu- bercles of birds, reptiles, and fishes, and the quadri- geminal bodies of the mammalia and man, as essen- tially analogous masses ; the quadrigeminal appear- ance in mammiferous tribes, he conceives to arise from a transverse furrow, which, in the human kind, commonly passes across the middle of the mass, which, in the carnivora, runs more anteriorly, and in the ru- minatia and rodentia, passes more posteriorly, and thus makes the two pairs of tubercles appear of nearly equal size, or causes the front or back pair to predom- inate.! The two pairs of tubercles, therefore, vary in proportionate size in the different tribes of mammif- erous animals, precisely as do the median and later- al lobes of the cerebellum. Now if, according to M. Serres, the dissimilar development of the different pairs of the quadrigeminal bodies does not prove their independence, 1 do not see that it is reasonable to regard diversity of development of the median and lateral lobes of the cerebellum as any proof of their independence. M. Serres thinks that the spinal cord, the median lobe of the cerebellum, and the quadrigeminal tuber- * Rapport, &c. p. 66. t Ibid. p. 68. 17 130 cles are developed in the direct ratio of each other, and the inverse ratio of the cerebellar hemispheres and annular protuberance, I have said that M. Serres himself excepts the class of reptiles from this law, and I have added oth- er facts which refute his opinion regarding the de- pendence of the median cerebellar lobe on the quad- rigeminal bodies. I have also shown above, that the direct ratio of development which M. Serres recog- nizes between the spinal cord, and the quadrigemin- al tubercles has no foundation in nature. An appeal to the same authority also proves that M. Serres deceives himself, when he fancies the spinal cord, the median cerebellar lobe, and the quadrigeminal tubercles to be developed inversely as the lateral parts of the cerebellum and annular protuberance. For in fishes, reptiles, and birds, there are no cerebellar hemis- pheres, and no annular protuberance. The lateral parts of the cerebellum and annular protuberance are, in fact, developed, in a greater or less degree in dif- ferent tribes, but never inversely as the optic tuber- cles and spinal cord are concerned. The flounder (pi. ii.fig. 7,) and carp (pi. ii. fig. 5,) have optic tuber- cles of greater size than the eel (pi. ii.fig. 1,) which of the three kinds, however, has the most voluminous spinal cord. M. Serres also notices several relations between the annular protuberance and different other cerebral parts. Dr. Gall and I were the first who showed the development of the annular protuberance in the direct ratio of the cerebellar hemispheres. No other one of the relations, mentioned by M. Serres, is con- stant ; and, consequently, no other can be laid down 131 as a law. The annular protuberance, for instance, is not regularly developed in the inverse ratio of the cerebellar median lobe, of the quadrigeminal tuber- cles, and spuial cord, as M. Serres pretends.* The annular protuberance in general, is relatively less con- siderable in women than in men; but the spinal cord is not developed in an inverse ratio in the two sexes. I shall expose another of M. Serres's errors, in sup- posing the annular protuberance to bear a directly proportionate development to the corpus callosum,! when I come to speak of the last-named cerebral mass. The advantage, it seems to me, would be little commensurate with the labor of ascertaining all the modifications presented by the cerebella of different animals, and giving titles to every lobule superadded to the primary median portion. Such inquiries ap- pear to me rather superfluous, as I view the entire cerebellum in the light of a single organ or apparatus, and as performing only one species of function. I have still to add, that the cerebellum like every other organ, is not only more or less complex in the different kinds of animals, but also that its several constituent parts are modified in the various individ- uals of the same species. The organ, too, I may here observe, is developed at rather a late period of life, a fact which I have already had occasion to cite, in showing that there was no regularity of proportion between the brain and cerebellum : I, however, call my readers' attention to the phenomenon, at present, in order that he may understand the tardy appear- ance of the function of the part (the sexual appetite.) * Rapport, &c. p. 69. t Ibid. p. 72. 132 For the sake of physiology, I also adduce in this place, the fact of the larger size, generally, of the cerebellum in men and males, than in women and females ol the several kinds. The cerebellum, then,is an apparatusof astructure, more or less complicated in different species of ani- mals, having a greater or smaller development in the two sexes, and in different individuals of the same kind, and being in a direct communication with the medulla oblongata and quadrigeminal tubercles. To obtain as clear and comprehensive ideas of the position and external and internal structure of the cerebellum, as possible, I request my reader to turn to, and peruse the plates in the order as follows :— For differences of form, of volume, and of super- ficial structure, see pi. ii. figs. 1, 2, 5, 7, 10, 11,12; pi. iii. figs. 2, 3, 4, 6,1,10, and 11 ; pi. iv. figs. 1,3. 5, and 6 ; pi. v. figs. 3,4, 5, and 6 ; pi. vi. figs. 1 and 2. For the appearances and connexions in the me- dian line, examine pi. viii. fig. 2. In oviparous animals, the cerebellum is hollow, as is seen in pi. xi. fig. 3, 62. In the mammalia and man it is solid ; in them, there is nothing that can be likened to a cavity, except the separation between its primary portion and the medulla oblongata, or rather he posterior part of the annular protuberance ; see pi. vii. fig. 2, m; and pi. xi. fig. 1, m. The disposition of the cerebellar ramifications, from birds up to man, is lamellar, as it is presented in pi. iii. fig. 1 ; pi. viii. fig. 1 and 2 ; pi. ix. fig. 1 and 2; and pi. xi. figs. 1, 3. For the appearance and structure of the cerebellar 133 commissure (annular protuberance,) inspect pi. iv. fig. 2; pi. v. figs. 3 and 5; pi. vi. fig. 11,2; and pi. viii. figs. 1 and 2. The ganglion of the cerebellum (dentated body) is represented in pi. viii. figs. 1,2; and pi. xi. fig. 1, B.s. To demonstrate the connexion of the cerebellum with a bundle of the restiform body, the medulla ob- longata must be pushed to one side, and the auditory nerve and a thin layer interposed between the me- dulla and the cerebellum, scraped off with the handle of the scalpel. The second bundle of the restiform body, reckoning from the posterior pyramid, will then be seen to plunge into the cerebellum. By entering the point of the knife at the insertion of this bundle, and cutting the cerebellum vertically, so that about two thirds of its substance may be left externally, and the other third remain internally, the communication of the cerebellum with the medulla oblongata, its ganglion from the entrance of the connecting bundle of the restiform body to about its middle, the ramifi- cations of the white substance, and the peripheral ex- tremities of the various branches universally covered with cineritious matter, constituting the appearance denominated arbor vitae, and all will be exposed. These peculiarities are represented in pi. viii. fig. 1. To see these uniting fibres of the cerebellum, com- posing the annular protuberance or commissure, are distinct from those of the bundle that connects it with the medulla oblongata, the last named part must be turned aside, and the vocal, glossopharyngeal, facial, and auditory nerves removed with the handle of the scalpel; the fibres of union will now be seen 134 gathering themselves from the peripheral parts, and lying over the bundle that springs from the medulla oblongata, and plunges into the cerebellar ganglion. Finally, every cut in the direction of the cerebellar lamellae exhibits a white surface, as is pictured in pi. viii. fig. 2. 135 SECTION VI. Of the Brain. In the preceding section, I have shown anatomy, physiology, and pathology, concurring to prove the cerebellum a single and peculiar instrument. In this respect, it is the opposite of the mass properly styled brain. I have, already, exposed the anatomical proofs of the brain's complexness, and for the evi- dence which physiology and pathology afford, referred my reader to the respective treatises upon these subjects. * Conviction of the brain, properly so called, being an assemblage of instruments, is readily obtained ; but to specify the limits of these instruments, individ- ually in the different species of animals, is a matter of extreme difficulty, if it be not, perhaps, impossible. Let us follow the procedure of nature in this part of our inquiry, and commencing with the most sim- ple brains, pursue them in their increasing complex- ness as we mount in the scale of beings, until we ar- rive at that of man, the most complicated of all. They who have gone into the comparative anatomy of the nervous masses, have constantly assumed the human brain as their type of comparison. This they have always viewed as a simple mass ; and then the hemispheres, the three lobes, the callous body the * Phrenology, or the Doctrine of the Mind ; Lond. 1825, and Obser- vations on Insanity ; Lond. 1816. 136 anterior, middle and posterior commissures, the in- fundibulum, the mamillary bodies, the fornix, the septum lucidum, the hyppoeampus's foot, the striated bodies, the optic thalami, the semicircular taenia, the quadrigeminal tubercles, the aqueduct of Sylvius, the valve of Vieussens, peduncles of the brain, the an- nular protuberance, the medulla oblongata with its pyramidal, olivary, and restiform eminences, and last- ly, the ventriclesandtheir communications, have been their grand objects of comparison. The existence of parts as this specimen of the nomenclature, in use, sufficiently proves, appears, therefore, to be admitted, or denied according to mere physical indications, the form and situation of the masses being especial guides to the conclusions formed. But this mode of studying the comparative anat- omy of the brain is insufficient. In the first place, it is certain that the mass, styled brain, consists of a multiplicity of instiuments performing, particular functions ; again, it is undeniable that the cerebral parts, as they are spoken of, in systems of descriptive anatomy, do not constitute entire and special organs , that several of them, indeed, occasionally go to com- pose a single apparatus, a circumstance which we have observed in reference to the cerebellum, when treating of that part. Further, it is no less obvious that the identity of the individual organs in the vari- ous classes of animals, ought to be determined by means of physiology, seeing that the forms of those which are known to be analogous often vary im- mensely. I have already said, that no anatomist, who, in ignorance of the sense of smell, should examine the mere configuration of the encephalic masses, 137 would venture to maintain that the olfactory nerves of the skate, flounder, fowl, seal, and ox, were mass- es performing analogous functions. And the out- ward appearances of the other cerebral instruments are not less diversified than are those of the organ of smell. It is, consequently, in vain attempting to ad- vance the comparative anatomy of the brain, without a knowledge of the affective and intellectual faculties of animals and of the functions performed by the different cerebral organs. The brain being made up of very many parts, whose functions are entirely dissimilar, the connexion of these with the nervous masses of voluntary motion, and of the five external senses, with the spinal cord in particular, requires to be examined. The cerebral organs have several primary roots, or bundles in the medulla oblongata ; these bundles have been particu- larized by the names anterior and posterior pyrami- dal, and olivary, and restiform bodies. From what has been already said, however, it is evident that the last-mentioned masses do not belong exclusively to the brain; we have seen that they include the roots of several nerves, and the primary bundles of the ce- rebellum. In the human kind all the three portions ofthe medulla oblongata are very distinct; but they severally become less and less evident as we descend in the scale of beings, and when we arrive at fishes we are almost tempted to doubt their existence alto- gether. Some, indeed, go so far as to deny these animals a brain. To me, however, it appears that every vertebral animal has a brain, in the strict and proper sense of the word; all have a nervous mass 18 138 superadded to the nerves of the external senses and voluntary motion ; and fishes, which, besides a cere- bellum, seem to have ganglions of nerves of sense only, may be proved to possess a true brain in addi- tion. The proof lies in this, that ganglions in gene- ral are proportionate to the nerves arising from them ; but the ganglions of the skate, and the three pairs of ganglions which, in the eel, are regarded as the ori- gins of the olfactory nerves, and the optic ganglions of the carp, pike, and many others of the class, are much too large in proportion to the nerves which is- sue from them. I, therfore, contend, that the olfac- tory and optic nerves of fishes communicate with certain cerebral parts, destined to peculiar functions, precisely as the same nerves do in birds and the mammalia, with this difference only, that the masses they communicate with, are of different sizes in these different species of animals. I repeat, then, that with M. Arsacky,* I conceive the complex structure of the optic ganglions in fishes to explain the functions which in reptiles, birds, and mammiferous animals, are obvionslyr performed by certain parts with which the optic nerves communicate. I apply the same idea to the ganglions of the olfactory nerves. In the eel for example, I only give the anterior pair to these nerves ; and in the skate, no more than the outer parts of the ganglions with which they com- municate. M. Carus, in his work on the brain,! broaches an idea that deserves a passing notice : it is to deter- * Dissertatio de Piscium Cerebro et Medulla Spinali, Hate, 1833. t Carus, Darstellung des Gehirns, Leipzig, 1814. 139 mine whether, when the cerebral parts are separated from each other at their peripheral extremities, this is to be regarded as a sign of perfection or of imper- fection. M. Carus himself considers the brain to be perfect in proportion as its masses approach unity. The brain of the eel is, according to him, extremely imperfect, on account of the separation of its con- stituent parts. This opinion seems to me too general, and but little satisfactory. We know that the brain and the cerebellum are always separate from each other. In proportion too as the last is perfected in the four classes of vertebral animals, its different parts be- come more numerous, more distinct, and lie farther from each other, especially towards their peripheral extremities. The brains of reptiles, of birds, and of several mammiferous animals, consist of two smooth hemispheres : in proportion, however, as the brain in superior classes of beings has more numerous offi- ces to perform, that is, as it increases in perfection, the division into lobes becomes distinct, and convo- lutions appear. The cerebral hemispheres of the hu- man foetus are at first smooth, but as the encephalon is developed, the separation of its peripheral parts o-rows ever more conspicuous. I divide the functions of the brain into two class- es : viz., affective and intellectual; and, in harmony with this physiological division, I recognize two kinds of cerebral parts. The anterior pyramidal bodies I consider the rudiments of such as belong to the intel- lectual operations ; and the other bundles of the me- dulla oblongata (in man they consist of the olivary 140 and part of the restiform bodies) which run across the annular protuberance to communicate with many of the cerebral masses, as the roots of those that per- tain to the affective manifestations. This separation into two systems of parts is very evident from the medulla oblongata upwards, as far as the pretended optic thalami and striated bodies in man and the mammalia. Let us then examine them, one after another, through their entire course, com- mencing with the bundles of the intellectual faculties. The pyramidal bodies are scarcely to be demon- strated in birds, and still less are they to be seen in reptiles and fishes; in the lowest mammiferous tribes, however, they are abundantly evident. They differ in general as to their size and length, not only in the various species of animals, but also in individ- uals of the same, especially of the human kind. In man they usually commence about twelve or fifteen lines below the annular protuberance. As they ap- proach this mass, they increase gradually in size, and it is in consequence of this structure that they have obtained their name. There is a striking peculiarity in the mode of ori- gin of these bundles : the primary fibres of each do not issue from the same side as that on which they lie, but uniting, in the first instance, into two, three, or as many as five little cords, they cross the mesial line of the body, one above another, from below up- wards : the bundles of the right pyramidal body, therefore, come from the left side, and those of the left pyramidal body from the right side of the spinal cord. The structure just described is termed the 141 decussation of the pyramidal bodies. It is a con- stant peculiarity : but it is modified as the number of decussating cords is concerned. When they are nu- merous, the appearance that results very much resem- bles plaited straw. In some very rare instances, the two pyramidal bodies cross, as entire and undivided masses, from one side to the other. The decussation of the pyramidal bodies is a point of much importance in a physiological and patholog- ical point of view. It is very long since cases of dis- ease impressed the idea of a nervous decussation on the minds of medical men. Lesions on one side of the head were often observed to occasion so unfortu- nate a symptom as palsy on the opposite side of the body. Hippocrates himself mentions the circum- stance ; but Areteeus was the first who attempted to explain it, by supposing a decussation of the nerves at their origin in the brain. Dion Cassius is the next who speaks of a decussation of the cerebral nerves and spinal cord ; but with him the subject dropt, and the attention of the medical world was only recalled to the fact in 1581, by Fabricius Hildanus. The true decussation of the pyramidal bodies, however, was first described by Misticheili, in 1709: it was noticed by Petit in the year following, and at later periods by Lieutaud, Santorini, and Winslow. The same authors also speak of other decussations, but probably on mere supposition. Modern anatomists, before Dr. Gall and myself, were divided in opinion upon the subject of decus- sation. Many admitted the fact, but no one pointed Out the place of its existence, Vicq d'Azyr, for ex- 142 ample, confounds the simple transverse fibres be- tween the two halves of the spinal cord with the true decussation of the pyramidal bodies. Many others, among the number Prochaska, Barthez, Sabatier, Boyer, Dumas, Bichat, and Chaussier, have, in the most positive terms, denied the decussation of the pyramidal bundles altogether, as we have shown in our reply to the report of the Committee of the French Institute upon our Anatomical Memoir. To demonstrate the decussation of the pyramidal bundles, we do not require any such maceration as Santorini believed necessary. It is sufficient to strip off the pia mater to show the structure. Let a slight cut be made through the membrane in the me- dian line, without implicating the cords beneath, the edges then separated gently and the decussation will appear. It will now be easy to reckon the number of bundles, and to take them away in succession with the handle of the scalpel. (PL viii. fig. 1 — 1.) The decussation at this place is incontestable; but whether there be any similar peculiarity in other situations, and whether that of the pyramidal bodies suffices to explain all pathological phenomena, are points that still remain undetermined. Some authors believe that the bad symptoms which attend lesions of the encephalon are always manifested on the side of the body opposite to that on which the injury occurs. Others again cite cases where injuries of one cerebral hemisphere have caus- ed pathological symptoms on the same side of the body. ' Although the palsy of the body,' says Haller,* * Physiologia, t. iv. p. 333. 143 < produced by injury done to the brain, be commonly manifested on the opposite side, it often enough happens that derangements of the brain and cerebel- lum affect the same side (as that on which they hap- pen.) ' He quotes De Haen, Schlichting, Morgagni, and others, in illustration of the fact. Prochaska believed that when the opposite side of the body suf- fers from cerebral affections, it is principally when the striated bodies are the seats of disease. Anatomy has as yet demonstrated no other decus- sation in the medulla oblongata than that of the pyr- amidal bundles. No crossing fibres has ever been found of the primary bundles of the cerebellum, nor of the posterior cerebral lobes, although physiological experiments and pathological facts tend alike to prove that the influence of the cerebellar hemispheres is propagated to the opposite side of the body. May not the cerebellum possibly act only through the me- dium of the brain? To such an hypothesis the ina- bility to perceive any proper lesion of the brain can- not be well opposed as an objection ; because it is not at all times possible to determine precisely' whether the cerebral fibres are healthy or diseased. The le- sions may be perceptible in one and not in another part. I conceive that the cerebellum may be evi- dently disordered, and that the brain may suffer, in consequence, without our being able to detect any traces of disease in its organization, whilst the oppo- side side of the body exhibits pathological symptoms. The connexions of the various parts, and the result- ing influence of each on the others reciprocally, ren- der observations on these matters difficult, and the 144 conclusions deduced more or less suspicious. Far- ther researches on the decussation of the nervous parts, not immediately connected with the masses of the anterior pyramidal bundles, are still wanted. The optic nerves decussate partially, and this is the cause why the eye is frequently deranged on the same side as that on which the brain is diseased. Let us now follow the pyramidal bundles in their course towards the annular protuberance ; and first, let us remark the fibres which are detached from the pyramidal, towards and around the olivary bodies, the media of communication, probably, between these different bundles of the medulla oblongata. (PI. viii. fig. 2, 64.) May not these connecting fibres explain the influence of the lateral cerebral parts upon the opposite sides of the body ? The pyramidal bodies, just as they enter the an- nular protuberance, are somewhat contracted in their thickness (ib. c.) but they are, by no means, interrupted in their course. Immediately alter having plunged into that mass, they separate into several bundles, and are mingled with cineritious substance (ib. f) Here many new fibres arise and join the others ; all advance, some of them disposed in layers, and some intersecting the bundles of the annular protuberance. The pyramidal bodies are so mnch increased in their passage, that on emerging from the annular protuberance, they compose the anterior and outer two-third parts of the cerebral crura or legs (ib.£.) To see the structure of the annular protuberance distinctly, that is to say, to see the transverse uniting 145 fibres of the cerebellar hemispheres, the longitudinal fibres communicating"with the pyramidal bodies, and the crura of the brain and the cineritious substance in- termingled with each, an incision of about a line in depth must be made across the transverse fibres: if the cut be made deeper than this, it must not be carried in a straight line, but in the slightly-curved direction of the longitudinal bundles ; the transverse must now be separated from the longitudinal layers with the scalpel, by pushing those on the outside, towards the hemispheres of the cerebellum, and those on the inside, towards the mesial line of the annular protuberance. By this means, the mode in which the longitudinal, or bundles of the pyramidal bodies are augmented in the annular protuberance, as it were in a true gang- lion, is made evident. (PL vii. fig. 2, 88 ; and pi. ix. fig. 2,/.) If these longitudinal bundles only are to be exam- ined, it is sufficient, by pushing the handle of the scalpel upwards from its inferior edge, to remove the transverse layer of the annular protuberance that covers them. Certain it is, therefore, that great errors are com- mitted, when the two crura of the brain are described as blended together, and the annular protuberance is styled a compound of the medullary or white sub- stances of the brain and cerebellum. The great bundles called crura of the brain, thus appear to be, in part, at least, a continuation of the pyramidal bodies increased in size and in perfection. These crura, as they advance, also contain cineri- 19 146 tious matter in their interior, from which, additional fibres are continually sent off, to join and strengthen those that have come from below. In mammiferous^tribes, the cerebral crura are very evidently divided into two parts, viz., an interior and external, and a posterior and internal mass. Two superficial furrows mark their limits respectively. They bear no regular proportion to each other. In the human kind, the anterior and external portion com- poses, as I have already said, two-thirds at least, of the entire crura ; but in the lower animals, the posterior is, by far the more considerable portion of the two. Before advancing further in our examination of the longitudinal bundles which we have followed from the pyramidal bodies across the annular pro- tuberance, let us first consider the origin and progress of the bundles that compose the posterior and inner portion of the cerebral crura. I have already had occasion to say that anatomists, besides the pyramidal, speak of the olivary and res- tiform bodies of the medulla oblongata of man. I have also shown that the restiform bodies contain the origins of the primary bundles of the cerebellum, and of the vocal, glossopharyngeal, facial, and trige- minal nerves. The remaining fibres of these, and the fasciculi of the olivary bodies, mount behind the ganglion of the pyramidal bundles in the annular pro- tuberance, and,joining themselves with, aid the com- pletion of the cerebral crura. In their course, they gain some increase in size, which however, is incon- siderable compared with that of the pyramidal bun- dles. (PL vii. fig. 2, 87,90; and pi. ix. fig. 2, a 70, 70.) 147 The olivary bodies are, themselves, true ganglions, and present the general forms (pi. ix. fig. 2. a,) and modifications observable in the ganglion or dentated body of the cerebellum. (PL ix. fig. 2, s.) Their eize varies greatly in different individuals. The cin- eritious and white substances are observed to be va- riously distributed throughout them. The modified appearances of the interior of the olivary bodies de- pend, as in other cases, on the mode in which they are incised for examination. The second, or posterior and inner portion of the cerebral crura, is intimately connected with quadri- geminal bodies. In the mammalia, it is much more voluminous than the anterior mass; and as we de- scend in the scale of beings, its relative proportion increases continually. These two portions of the cerebral crura contain, so to say, the roots or primary bundles of the hemis- pheres of the brain, properly so called. They, how- ever, it is evident, must be immensely increased in volume before they can form such a mass as the brain; It is as the upper extremity of the anterior portion, where the optic nerve winds over, and is attached to it by a pulpy layer; that is to say, at the outer part of the striated bodies, that the great aug- mentation takes place. After this, the fibres advance of unequal lengths, and, expanding into layers cover- ed on their peripheral extremities with cineritious substance, ultimately form the inferior, anterior, and external convolutions of the front and middle cerebral lobes. To show that the lower and inner convolutions of the 148 middle lobe, are formed by the anterior and outer crural bundles, the middle lobe must be removed. This is easily effected, as it is separated from the anterior lobe by the fissure of Sylvius. Besides the depth and extent of the Sylvian fissure by this means exposed, certain short convolutions which do not reach the surface, will also be brought into view. These convolutions lie hidden between the middle lobe and the superior cerebral parts. The bundles which issue from under the optic nerve, will also now be seen to belong to the middle lobe, and to the anterior part of the posterior lobe. (PL viii. fig. 1, w, w.) If the entire outer part of the striated bodies be removed, the manner in which the convolutions, situ- ated along the middle region of the hemispheres, on a level with the temples, arise from the bundles in continuation with the pyramidal bodies, will be made apparent. (PL ix. fig. 1.) The pyramidal bodies, their ganglions in the annular protuberance, the an- terior and outer portions of the cerebral crura, and the convolutions in which their bundles terminate, are always developed in the direct ratio of each other. Let us now trace the posterior and inner bundles of the cerebral crura to their termination. These plunge into a thick, massy, and firm ganglion, flat- tened in the middle, and unequal above, and poste- riorly ; this is generally known under the name of optic thalamus, it having been long regarded as the originof the visual nerve. The error, here committed, I have exposed in speakingof the apparatus of vision. These ganglions, commonly called thalami, are developed in the direct ratio of the cerebral convolu- 149 lions dependent on them. The posterior and inner portions of the cerebral crura being larger in the lower animals than the anterior and outer masses of the same, it follows that the convolutions of the upper and posterior parts of the hemispheres, must be more considerable than those of the anterior and middle lobes. The most internal part of the thalamus, is the largest in animals, consequently, so is the mass of convolutions that belongs to it* In the interior of the cerebral ganglion we are now discussing (pi. ix. fig. 2, p,) there are a great number of very fine nervous filaments; these unite at its superior edge into bundles, which then diverge towards the convolutions in the manner of rays. The two portions of the ascending masses, called cerebral crura, which I have just described, may be separated from each other either by the blow-pipe, or a stream of water. At the place, however, where they issue from the thalami to enter the striated bo- dies, their fibres are all so intimately united by a transverse tissue, that any farther parition of the two portions becomes impossible. The anterior bundles of the thalamus traverse the striated bodies. These are so named, because, when cut in the usual mode, anatomists fancied they be- held alternate streaks of white, and of cineritious substance. But the gray matter is not disposed in bundles ; it is a mere mass traversed by white diverg- ing fibres. By scraping away to about the middle, or to the place where the large white bundles pass, the cineritious substance will be seen disposed in the form of streaks between them : a closer inspec- 150 tion, however, proves that it only lies in the intervals between the fibrous bundles. The masses styled optic thalami and striated bo- dies, therefore, are true ganglions, in which the pri- mary bundles of the brain are increased in their prog- ress to completion in the convolutions of the brain ; for the radiated diverging fasciculi expand into lay- ers, and being covered with cineritious substance on their extremities, compose the convolutions. The faultiness of the ordinary method of examin- ing the structure of the brain will now be, in some degree, appreciated. Instead of tracing the masses from their rudimentary state upwards to completion, anatomists have been in the habit of commencing the dissection by mutilating the parts when already ar- rived at perfection. By scraping the parts, Vieussens followed, and has given a rude drawing of the nervous bundles in con- nexion with the pyramidal bodies. These fasciculi, however, he derives from his oval centre : he was al- together ignorant of their destination — the forma- tion of the convolutions. He conceived them all to unite in the pyramidal bodies ; he, therefore, had no idea of the successive additions to, or of the aug- mentations of, the primary bundles. Vicq d'Azyr has attempted to imitate the prepara- tion of Vieussens, in his twenty-second and twenty- third plates; but the mass of gray substance, and the nervous bundles which traverse, and partly arise from it lying obliquely, he could not possibly succeed by his horizontal incisions. In the striated bodies he only saw alternate streaks of white and gray sub- 151 stance ; these he also regarded as coming from above downwards, to pass united in a single bundle across the annular protuberance. He has, moreover, neg- lected several rudimentary bundles entirely; he regarded the streaks of the superior as shorter than those of the inferior parts, in consequence of having cut them first, and he was quite ignorant of their prolongation into the convolutions. He only makes them proceed forwards, overlooking their sideward and backward directions altogether. Vicq d'Azyr, therefore, has done nothing more than picture, and that in a faulty manner too, mutilated pieces of the encephalon. I conceive it of importance further to remark, that the nervous fasciculi are less numerous but larger in the posterior and middle than in the anterior region. In the latter they are very numerous, but also very small. (PL ix. fig. 2; and pi. x. fig. 1, A. P. P.) This anatomical fact corresponds with what we know of the physiology of the brain, and explains the reason why the organs situated in the forehead are more numerous but smaller than those which lie in the occipital region. Let us now glance over the comparative anatomy of the cerebral parts, the structure of which we have examined particularly in man. The anterior pyramidal bodies are generally dis- tinct in mammiferous tribes, but they are compara- tively smaller than in the human kind. The lateral parts of the medulla oblongata are not formed like the olivary and restiform bodies with which they cor- respond in man ; their fibres, however, are certainly 152 prolonged beneath and across the transverse uniting fibres of the cerebellum. At their exit from this mass, the anterior and external parts of the cerebral crura are observed to be proportionately smaller than the interior and posterior portions. The rela- tive size of the two portions of the crura, indeed, are found to vary exceedingly in the different tribes of the mammalia. The anterior and outer bundles, or continuations of the pyramidal bodies, extend under the optic nerves (which by their external edges com- municate with the cerebral masses precisely as in man,) and on the external parts of the striated bodies gain an increase of size in the direct ratio of the anterior convolutions of the middle lobes, of the outer convolutions of the front lobes, and of those around the fissure of Sylvius. The description of this external portion of the striated bodies is entirely omitted in the work of Tiedemann. The posterior and internal parts of the cerebral crura are intimately connected with the quadrigeminal bodies ; they then plunge into the pretended optic thalami, and join themselves to the striated bodies ; their structure, in short, is analogous to that of the same parts in man. In birds and the inferior classes all traces of pyra- midal bodies, visible in the mammiferous tribes, dis- appear ; and all analogy, as regards form, with the medulla oblongata of man is lost. The medulla ob- longata, however, of all vertebral animals is invaria- bly augmented downwardly and outwardly in pro- portion as nerves of greater or smaller size are de- tached, or as the rudimentary bundles of the proper cerebral masses are thence derived. The mere out- 153 ward form, here as elsewhere, is not the essential consideration. It is quite certain that several parts of the medulla oblongata proceed forwards, and pass under the optic nerve ; and that in birds and reptiles there lies a mass below the posterior cerebral lobes, and on the inner side of the crura, which resembles in everything the supposed optic thalamus; and, finally, that in the two classes mentioned, the advancing bundles encounter true striated bodies. (PL xi. fig. 2 and 3, I. I.) The pretended optic thalami and striated bodies, or the two principal ganglions of the cerebral hemis- pheres, consequently, exist in birds and reptiles, pre- cisely as they do in man and the mammalia. M. Serres must therefore be mistaken when he denies the existence of striated bodies in the brains of these animals.* Dr. Gall and I were unquestionably the first who distinguished the true optic ganglions from the sup- posed optic thalami, which are masses belonging to the brain, and who demonstrated the relations be- tween the two cerebral ganglions and the hemis- pheres. Among fishes, in fine, certain cerebral masses in the form of ganglions, and covered externally with cineritious substance, are always to be found. When treating of the optic and olfactory nerves, I proved that the entire encephalic mass could not be destined to originate them. But it is a difficult task to com- pare analogous cerebral parts in different tribes and classes of animals. In fishes, the medulla oblongata * Rapport, &c. p. 70. 20 154 is evidently continued forwards, and from it are de- tached, in succession, the primary bundles of the cerebellum, and of the cerebral nerves; but M. Serres promulgates an error when he says, that the cerebral hemispheres of fishes are simple rounded bulbs, lying before the quadrigeminal tubercles, in which the crura expand. Two longitudinal bands we can ob- serve continued onwards to the olfactory nerves, with which a larger or smaller number of ganglions com- municate ; but whilst the functions of these shall remain undiscovered, they can only be designated according to their numerical order. (PL ii. fig. 1 and 13; 1, 2, 3, 4.) The anatomists also certainly err, who speak of the restiform bodies as simple bun- dles. The olivary bodies, as they are not to be de- monstrated in the greater number of animals, cannot belong to the quadrigeminal tubercles, as M. Tiede- mann supposes. In reptiles, birds, and the mammalia, the prolon- gation of the two great cerebral ganglions compose the hemispheres, as they are styled, of the brain. The volume of these varies extremely in different kinds, and even in different individuals of the same species of animals, and this not only in their totality, but also as their various portions are concerned. The external surface of the cerebral hemispheres in reptiles, birds, and several mammalia, is smooth. The division into three lobes, however, is always marked by slight furrows, and the individual parts are dissimilarly developed in different situations. In the greater number of the mammalia, as in man, the hemispheres are convoluted, and furrowed to a greater or less depth. 155 Of the Structure of the Convolutions, and of the possibility of unfolding them. The unfolding of the cerebral convolutions has some- times been considered as the essential point in the anatomical discoveries of Dr. Gall and myself. This is the reason why some have taken particular pains in combating the possibility of this operation. The fact is in itself of great importance; it affords sev- eral explanations that particularly interest both phy- siology and pathology. Many cases of disease would be quite inexplicable without a knowledge of the structure of the cerebral convolutions ; yet not this, but the demonstration of the plurality of the nervous instruments, their independent existence, and their connexions with each other, constitute the essentials of our anatomical inquiries. It has often been, and is still said, that the vascu- lar membrane, by plunging at intervals among the white substance, to convey the blood-vessels neces- sary for its nourishment, is the cause of the cerebral convolutions and anfractuosities ; but no part of the structure is thus mechanical. The convolutions in- ternally consist of white fibres, which are covered on their extremities with cineritious substance. These fibres, which terminate the nervous bundles of the cerebral crura, are not all of the same length. Many, especially of those which are situated on the outer sides of the convolutions, terminate immediately be- yond the exterior wails of the cavities .; the others extend to distances progressively greater as they run 156 more centrally, those of the interior extending the farthest of all. It is in consequence of this peculiar structure that prolongations and depressions are form- ed on the surface of the hemispheres. The cineri- tious substance follows all the forms composed by the white fibres, and covers every elevation and depres- sion with a layer. The fibres of analogous bundles are not prolonged in every individual to the same distance, not even in the two hemispheres of the same brain. I find that the parts which are most largely developed have the fewest inequalities on the surface of the convolutions, the fewest depressions, and even the smallest num- ber of anfractuosities. They are simply voluminous, and their peripheries are regular and smooth. The convolutions are for the the most part inclin- ed slightly to the roof of the ventricles; they rarely stand up vertically. Their peripheral edge is fre- quently depressed, and this gives them an appear- ance similar to that which a fold of paper takes when its edge is pressed lightly inwards. (PL ix. fig, 1 and 2.) When a convolution is cut across vertically, the white substance will be observed of greater thickness at its bottom than at its top. . This happens from the nervous fibres losing themselves sucessively on either side in the cineritious enveloping layer, whilst those of the centre only run to the extremity. A clean cut only shows the white substance of the convolutions as a simple mass. No line of separation can be perceived in any direction. Nevertheless, it may be demonstrated to consist of two layers covered 157 externally by cineritious matter. These layers meet in the middle line of the convolutions, and are slight- ly agglutinated by means of a very delicate neurilema. On this structure is founded the possibility of sep- arating, without injuring, the fibrous layers, and thus of extending or unfolding each convolution into a simple sheet. Before citing any anatomical evidence in support of the above fact, I shall give, as briefly as possible, the history of its discovery. Dr. Gall having had several opportunities of dissecting hydrocephalic heads, found, as Morgagni had before him, the brain distended like a large bladder, several convolutions having entirely, and others in part, disappeared. The internal surface of the enlarged cavities was uniformly white ; and, generally, the nervous fibres and the blood-vessels that accompanied them were distinctly perceptible. He also met with a female, fifty-four years of age, whose head was much en- larged, without doubt in consequence of considerable dropsy of the brain. In person she was thin, but she was as active and intelligent as women usually are in her sphere of life. Dr. Gall being convinced that the brain is indispensable to the intellectual manifestations, drew, as I have said in the preface, the same inference as Tulpius had done before, viz., that the encephalic mass cannot be disorganized or destroyed in those persons, who, being affected with hydrocephalus, still preserve their understanding en- tire ; and farther, that the structure of the brain must be different from what is commonly supposed. The female, whose case is quoted above, happen- 158 ing to die of an inflammation of the bowels, Dr. Gall found that the cerebral cavities contained about four pounds of pure and limpid water. The convolutions of the upper part of the forehead, and of the superior region of the head, had disappeared entirely ; lower down, however, they were distinct in different degrees. In the interior of the great cavities, the fibrous struc- ture and the blood-vessels appeared very conspicuous. I saw this head dissected at Dr. Gall's house, but neither of us at that time had any definite idea of the mode in which the cavities had been enlarged, the convolutions obliterated, and the cineritious sub- stance made to appear spread over the entire sur- face, like an envelope of nearly equal thickness. This case, however, gave a new impulse to our an- atomical inquiries on the encephalon. We began by attempting to imitate artificially the state of the brain in hydrocephalus. Having stripped off the pia mater, we insinuated our fingers into the great eavi- ties ; and by pressing, more particularly against their posterior walls, we found, with pleasure, that after overcoming a slight resistance at the commencement, the convolutions separated along their interior, with all readiness into two parts. Even this rude experi- ment made us conceive the possibility of the gradually increased and unremitting pressure of the water, as it accumulated in hydrocephalus, unfolding the hemis- pheres into a membraneous sheet, without destroying any of the nervous fibres. By degrees our anatomical discoveries were in- creased, an^ °ur ideas of the change effected on the cerebral masses in hydrocephalus became exact. 159 The imagination of Dr. Gall's auditors was some- how more struck by the experiment above related, than by the whole of our cerebral anatomy besides Our opponents, by the same reason, have conceived themselves particularly called upon to disprove its practicability. In their zeal, they have sometimes put sentences into our mouths which we never uttered; we have been made to say, for instance, that the en- tire brain could be unfolded into a membrane with- out any laceration of fibres ; our idea has also been travestied, by reporting that we regard each separate convolution as a sort of little purse, The question concerns the structure of the convo- lutions only, and the possibility of proving them composed of two distinct layers, separable from each other. Let us, therefore, proceed to the inquiry. If a convolution be cut vertically across to its base, a very gentle pressure with the finger on the cut surface will suffice to separate its two fibrous layers. The surfaces by which these were agglutinated, will, even after this rude procedure, remain perfectly smooth and equal. At the base of the convolutions there is a mass which prevents any further disjunction of their component layers. Of the structure of this mass I shall speak, when I treat of the commissures, or uniting fibres of the cerebral parts. If a portion of the hemisphere, lying above the ven- tricles, be taken in one hand, and the ventricular sur- face be lightly pressed on by the other, the mass at the base of the convolutions, which has just been mentioned, will be torn, and the two layers of the sev- eral convolutions then yield readily, and may be forced 160 apart by the fingers. Whilst this is doing, we may always observe a slight furrow along the line of every separation, and the blood-vessels coursing along the same. Now this could not happen, were not the convolutions composed of two fibrous layers, not uni- , ted by transverse fibres, but simply agglutinated by means of a fine and yielding cellular tissue. If the convolutions be cut off externally to the cavities, they may be readily unfolded, and without any tearing of parts. The convolutions, hardened in alcohol, in diluted nitric or muriatic acid, or in oil by simple boiling, may also be unfolded with perfect ease in the middle line, and only in the middle line of their agglutination. No vestige of laceration will there be perceived, but the fibrous expansions on either side will become exceedingly distinct. It is objected that the fibres may be separated at every point, and by the side of the middle line of the convolutions. Now this is as it ought to be, be- cause each layer is made up of many fibres, running in one and the same direction. The fibres of every ligament and muscle may be parted in like manner ; but this fact does not do away with the existence of entire ligaments and muscles, distinct and easily sep- arable from each other. Moreover, the nervous fibres on the outer surfaces of the layers, as they are con- tinually and successively dipping into the cineri- tious substance, may the more readily be separated from each other, the more the bundles lie externally on which the attempt is made. To prove further that the convolutions consist of 161 two fibrous layers but slightly agglutinated, the fol- lowing experiment may be tried : — Let a convolution be cut transversely, and blown upon at random through a pipe; both the white and the gray substance may, although with some difficul- ty, be destroyed ; but no disjunction of fibres nor of the two substances will be effected. But let the stream of air be directed on its middle line, and it will instantly be split from the apex to the base. (PL ix. fig. 1, 1—2.) If the same experiment be made on a convolution that is slightly depressed at its summit, it will open at the base by a simple cleft, but at the upper part this will branch off towards the two corners. (PL ix. fig. 1,1 —2.) When, instead of air, water is thrown with a sy- ringe on a convolution cut transversely, the separa- tion is effected in a similar manner: this fluid too, may be pushed for three or four inches along the middle line, between the layers ; it will even follow all the windings, and fill all the subdivisions of the convolutions that occur in this space. If after their injection the superior edge of the convolutions be cut away longitudinally, to the depth of about two lines, they will be found divided into two equal parts ; and the manner in which the fibres penetrate and lose themselves in the cineritious substance on either side will also be disinctly seen. Water thrown with violence upon the outer sur- face of a convolution will wash away the gray and one half of the white substance; as soon, however, as it reaches the middle line, it will penetrate to the right and left, and separate the two layers to the ex- 21 162 tent of an inch or two each way, as in the former experiment. Here also, as in the former case, the direction and distribution of the nervous fibres will be rendered very apparent. All these demonstrations prove incontestably that the convolutions consist of two fibrous layers agglu- tinated together, and surrounded by cineritious sub- stance. Nevertheless, authors still continue to speak of the cerebral pulp, or of the medullary and pulpy substance of the convolutions. But the idea of a mere pulpy matter is in contradiction to all known anatomical and physiological phenomena. Were the white substance pulpy, it would be destroyed or car- ried away by a stream of air or water directed upon it. It would be impossible, on the supposition of a pulp, to account for the similar result of the various experiments related, viz., the regular separation of the convolutions into two layers along the course of their middle line. In connexion with the idea of a cerebral pulp, that of hydrocephalus, to any considerable extent, becomes an impossibility, because the slightest dis- tension of any one portion of the brain would tear the pulp, and the disease could no longer proceed. But many cerebral parts are often seen completely unfolded, and still resisting the contained fluid, although they be stretched into a membrane scarcely two lines in thickness. Similar changes, too, are frequently undergone by the majority of the convolu- tions without any laceration or destruction of parts. Some anatomists appear to have felt this difficulty, and, to escape, have said that the cineritious substance 163 was very tenacious, even more so than the white, and this quality enabled it to resist laceration, and to suffer the expansion peculiar to considerable hydro- cephalus. But all good anatomists know full well that the cineritious is much softer than the white substance ; that the first is never seen disposed in layers, except where the last occurs in distinct bundles ; indeed, that in the very places where the cineritious sub- stance appears in layers, it falls into pulp the mo- ment the white fibres are taken away. In hydrocephalus, some anatomists have pretended to see nothing more, no other change, than a mere extension of the cerebral cavities. But on this sup- position, how may the entire disappearance of the convolutions be explained ? Were the cavities merely distended, the convolutions would only be separated more widely from each other; they would never be unfolded ; their component layers would not, from a naturally vertical, assume a horizontal position. The structure of the convolutions once familiar, however, we readily conceive a capacity in the hem- ispheres to undergo great changes without the oc- currence of any actual disorganization. We even perceive that when the cerebral fibres chance to be elongated, this does not necessarily imply derange- ment of intimate structure: vision is well known often to remain perfect when the optic nerve is very much lengthened. Anatomy, consequently, shows how it comes that individuals affected with dropsy of the brain may manifest all their intellectual and affective faculties. 164 We cannot now say with Walter, Ackermann, and so many others, that in hydrocephalus there is destruc- tion or absorption of the organization, and that the mental functions are all necessarily annihilated. The physiology of the brain being now established, the existence of this mass of organs is seen clearly to be indispensable, and its disorganization impossible in those hydrocephalic persons who exhibit affective and intellectual faculties. All this is made evident by our discoveries in anatomy and physiology. It still remains for me to make some inquiries into the comparative anatomy of the cerebral hemis- pheres. To show the presence of the brain in the lower animals is not enough; the particular organs that compose the hemispheres must be determined in addition ; the resemblances to the three cerebral lobes of the human kind, and to the individual por- tions of each being also demonstrated. Anatomists are not even agreed as to the existence of the poste- rior lobes in all mammiferous tribes. Messrs. Cuvier, Tiedemann, Serres, and others, maintain that the posterior lobes of the brain are only found in man and the quadrumana. They rest their opinion on the fact of the cerebellum, in all the other classes, being uncovered by the brain. The conclusion here, how- ever, is faulty, and the generally horizontal posture of animals explains, in the most satisfactory mariner, why the cerebellum, instead of lying under, is situa- ted behind the posterior lobes. Let me observe, once for all, that no part whatsoever can be denied on account of mere difference of configuration. Were it thus, the existence, of the front and middle lobes, in 165 all the lower animals, might also be disputed with perfect propriety. The bulb of the olfactory nerve is covered by certain cerebral parts, in man, monkeys, and the phocse; but in the generality of mammifer- ous animals and birds, it lies, altogether, anterior to the cerebral hemispheres ; nevertheless, no one con- cludes that they, therefore, want the front lobes. On the other hand, it is a great error to assume with M. Serres,* as an axiom, that—'The encephalon of all vertebral animals is constructed after one uni- form type, and with the same elements,' or with M. Cuvier,! to say that — ' The brains of the mammalia have the same parts as that of man.' In principle, I maintain that the cerebral hemis- pheres of animals are composed of a greater or small- er number of parts, as different from each other as the optic from the auditory nerves. The existence of the posterior lobes of animals is not to be doubted, seeing that the ganglion, out of which they proceed (thalamus,) is found in them, as well as in man. Moreover, the functions of the human posterior cere- bral lobes are also manifested by animals. To the above, it is still necessary to add, that variety in per- ipheral expansions of individual organs, indicates neither the absence nor presence of any one in par- ticular : one hemisphere that is entirely smooth, and another that is furrowed in all directions, may both of them contain the same elementary parts. This con- sideration it was which induced me to say, that the comparative anatomy of the brain could not be ad- vanced without the assistance of physiology. With * Anatomie du Cerveau. ♦ Anat. Comparee, t. ii. 166 the aid of physiology, however, discoveries of great interest might, undoubtedly, be made. The analogy that exists between the brains of the cat family (pi, iv. fig. 5,) of the dog tribes (pi. iv. fig. 6,) of the sheep, monkey, and other kinds, is as striking as the general similarity of disposition and character of each. The same law holds in the case of man. In- dividual organs, however, are more or less developed in every species of the same genus. In pi. v. fig. 1 and 2, I have given representations of the brains of two species of monkey. They are, evidently, much alike, considered in general; but still, the anterior lobes in fig. 1, are smaller, comparatively, than in fig. 2. The brain of the ourang-outang is figured in the same plate, fig. 3 and 4, and the brain of an idiot girl, fig. 5 and 6. There is a striking general resem- blance between the two, yet the front lobes of the ourang-outang are more considerable than those of the idiot. In a precisely similar manner are the dif- ferent constituent parts of the healthy human brain dissimilarly developed, and their specification is matter of especial interest in the study of man, 167 Section VII. Of the Commissures or Fibres of Union. All the proper cerebral organs, like the other instru- ments of phrenic life, occur in pairs, or are double, from the medulla oblongata up to their expansion in the convolutions. This, probably, happens because of their importance, and to the end, that the con- generate parts may supply each other's places, should either chance to be injured. But, in addition to the parts already described, there are others still that contribute to the formation of the brain. These have been long known by the name of commissures. Anatomists speak of the great commissure or cor- pus callosum, and of the anterior, middle, and poste- rior commissures of the brain. Until Dr. Gall and I published, it was the custom to take merely me- chanical views of these, without attempting to dis- cover their relations with the other cerebral parts, their derivations, or the causes of their dissimilarity in different animals; and this too, although Vicq d'Azyr had said* that ' the commissures seemed to exist for the purpose of establishing sympathetic communications between the different parts of the brain.' The successive additions made to the diverging bundles, in their course from the medulla oblongata to the convolutions, is a point in anatomy that is now generally admitted. I conceive that I have discov- * Memoires de l'Acad. des Sciences de Paris, 1781. 168 ered another or second order of fibres, which, with Dr. Gall, I distinguish by the title, converging fibres, or apparatus of union. This discovery, however, is disputed. M. Tiedemann calls it a chimera.* Dr. Gall, in the sixth volume of his work, in 8 vols., on the Functions of the Brain, replies at great length to M. Tiedemann, and to those who dispute the con- verging fibres. For my part, I here address the same reproach to M. Tiedemann, which I have laid against him in another place, and in a general man- ner. He has admitted laws from researches made on the brain of the embryo, which are in contradic- tion with the structure demonstrable in the adult. Nothing can be easier than, by dissection, to prove the two orders of cerebral fibres: the diverging and the converging, and to show that the mass or bundle called corpus callosum belongs to the converging order. The corpus callosum extends anteriorly and poste- riorly beyond the striated bodies. (PL x. fig. 1.) Its thickness, at either extremity, is greater than at its middle. (PL vii. fig. 2, \, P.) The fibres which compose the folds of the corpus callosum, proceed evidently from the convolutions which form the most anterior and posterior parts of the hemispheres, and by no means from the thalami and striated bodies. (PL x. fig. 1, 39 and 40.) Their direction, consequently, is entirely different from that of the bundles constituting either of the two great cerebral ganglions. If the fibres of the supposed thalami be * Bildungs-geschichte des Gehirns, Niirnberg, 1816, p. 156. 169 followed towards the posterior lobes, by scraping the parts, the converging fibres may readily be observed passing out betwixt them. (PL x. fig. 1, P.) More- over, the two folds (ib. 39 and 40) of the corpus callosum are always proportionate in size to the fis- sures that part the hemispheres before and behind, or otherwise, to the convolutions on either side of the fissures, but by no means to the diverging fibres. The corpus callosum is softer and much larger than the bundles of the striated bodies; the fibres of either of these masses, consequently, cannot be mere continuations of the other. But, in fact, the entire difference of the two orders of fibres cannot possibly be called in question, saving at. the middle of the corpus callosum, or place oppo- site the striated bodies ; and even here, the analogy that exists between the middle and the extremities of the mass, may be assumed a sufficient index of an analogous formation. The scalpel, however, sets the matter completely at rest. The converging mass, I must not forget to state, does indeed communicate with the great cerebral ganglions, by means of a su- perficial band or layer, which has obtained the title of semicircular tape-worm. On examining the mid- dle partof the corpus callosum attentively, its edge, opposite the great cerebral ganglions, will be seen to consist of this semicircular band alone. It is com- posed of its own fibres, so to say, and increases in thickness as the middle line is approached ; for the fibres become gradually thicker till they meet, in the same way as the folds increase, as they advance on each side to their junction. 22 170 In attempting to imitate the naturally unfolded state of the brain in hydrocephalus, by pressing upon the roof of the cavities with the fingers, a certain quantity of resistance is always experienced at the bottoms of the convolutions. This proceeds from a tissue formed by the interlacement of the two orders of cerebral fibres. This tissue once torn, the line between the layers of the convolutions is entered im- mediately, and they are then unfolded with perfect ease. Were the diverging fibres or bundles of the great cerebral ganglions prolonged directly into the corpus callosum, it would be extremely difficult to understand how they could be elongated to the de- gree occasionally observed in hydrocephalus. The disappearance of the convolutions too, would be al- together incomprehensible; the water would act against the corpus callosum and the walls of the cav- ities, but there would be no reason for the unfolding of the convolutions. With the true structure in view, however, all that happens in hydrocephalus is easily explained ; there is neither absorption nor increase of the cerebral parts: the converging and diverging fibres have but to change positions; to separate at the place of their intersection, at the bottoms of the convolutions; the convolutions to split in the line of their component layers, and the change is completed. I, for my own part, feel inclined rather to recognize increase than diminution of the cerebral mass in hy- drocephalus. Why, indeed, should not that happen in regard to the brain which so plainly occurs as the investing membranes are concerned ? How greatly is not the arachnoid coat, the dura mater, 171 and even the osseous covering of the whole aug- mented ? All concurs then to prove the presence of the two orders of fibres in the brain as well as in the cerebellum. And now a question of much interest presents it- self; it is this: are the bundles styled corpus cal- losum and annular protuberance, true commissures or organs of union ? It is quite certain that the an- nular protuberance belongs to the lateral parts of the cerebellum, and that it appears with, and is pro- portionate to, these. It is also undeniable, that the corpus callosum is in relation to the cerebral hemis- pheres, precisely as is the annular protuberance to the lateral parts of the cerebellum. We have seen, too, that both the brain and the cerebellum are com- posed of two orders of fibres. On the other hand, the nervous apparatus of animal life is universally double, and united in the middle line by means of commissures. I believe, indeed, that the law of commissures is quite general ; but I doubt of each con^enerate pair of fibres having its own commis- sure, or bundle uniting in the middle line. This, in the first place, cannot possibly be the case in the spinal cord and medulla oblongata, because the ap- paratus of union is there much less considerable than the several halves of these masses. The same thing may be said in regard to the annular protuberance and corpus callosum. These bundles, compared with the white masses of the cerebellar and cerebral hemispheres, are much too inconsiderable. It would seem, therefore, that a small mass is sufficient to unite the two congenerate halves. Still, the mass 172 that unites, and the mass that is united, not being of equal dimensions, does not gainsay the possibility of the commissures being proportionate to the congen- erate parts that are joined. M. Serres, maintains,* that the corpus callosum is proportionate to the annular protuberance, and that the hemispheres of the brain are developed in the direct ratio of those of the cerebellum. It is easy to demonstrate this error. The masses mentioned vary extremely, and are never developed directly in the ra- tio of each other, neither in different kinds, nor in dif- ferent individuals of the same kind of animals. To be convinced of this truth, it is enough to glance over the tables of the comparative sizes of the brain and cere- bellum, which various authors (among the number, M. Cuvier) have drawn up. The proportion between the brain and cerebellum even varies in the same individ- ual at different periods of life. The cerebellum at- tains its complete growth later than the cerebral parts generally. As to the proportion between the annular protuber- ance and cerebellar hemispheres, and that between the corpus callosum and hemispheres of the brain, recognized by M. Serres, these are facts announced by Dr. Gall and me, long before this gentleman's pub- lication appeared. It still remains to be seen, whether or not the annular protuberance and corpus callosum are true commissures. These parts are only found in man and the mammalia : in birds, reptiles, and fishes, they are wanting. Birds and reptiles, however, have un- * Rapport, &c, p. 72. 173 doubtedly cerebral hemispheres, with two great gang- lions; and, as in them, the other commissures, entitled anterior, middle, and posterior, are of a size propor- tionate to the lateral masses, and are situated as in man and other superior tribes, they cannot be assumed to supply the place of the corpus callosum. It follows, therefore, either that the union of the cerebral hem- ispheres of birds is established according to another law than that of the mammalia, or that the annular protuberance and corpus callosum are not true com- missures, in which event they would have to be con- sidered as mere constituent parts of the cerebellar and cerebral apparatus. Dr. Gall and I committed an error in the first volume of our large work, when we treated of a part in birds, as analogous to the cor- pus callosum of quadrupeds. In the succeeding sec- tion of this book, I shall show that the mass in ques- tion corresponds, not to the corpus callosum, but to the fornix of mammiferous animals. There, too, I shall prove that we did wrong, in classing the entire fornix among the commissures. My doubts of the propriety of regarding the annu- lar protuberance and corpus callosum as commissures, increase in consequence of the existence of two lon- gitudinal bands, running along the middle line of the latter, forming what is called its raphe (pi. x. fig. 1,) and of the layer of fibres between the raphe, and be- tween the two halves of the annular protuberance, similar to that which occurs between the peduncles of the brain. (PL vii. fig. 2. x, M, x-) Lastly, Reil relates a remarkable case* of a wo- * Archiv fur die Physiologie, B. ii. S.341. 174 man, above thirty years of age, whose intellectual faculties were very limited, and whose corpus callo- sum was found split in the middle line through its en- tire length. Last year, (1825,) through the kindness of Messrs. Morgan and Keys, surgeons to Guy's Hospital, Lon- don, I had an opportunity of seeing a similar case. The name of the man in whom it occurred was James Cardinal, a portrait of whom I gave, in 1815, in my work, entitled ' The Physiognomical System,' which Dr. Gall copied in his continuation of our large work, and which I myself re-published last year in my book on Phrenology. I do not think that any case more remarkable than James Cardi- nal's has ever been the subject of observation. He had hydrocephalus to an enormous amount, and man- ifested the affective and intellectual faculties. The greater part of the water was accumulated between the brain and dura mater, but the lateral cavities were at the same time distended by about a pint of fluid, which communicated freely with the liquid collected without the brain, as the corpus callosum, with its extreme folds, was split through its entire length along the median line. Its masses on either side, together with the lateral convolutions, were quite distinct. The union of the corpus callosum from this would not appear essentially necessary to the unity of function of the two cerebral hemispheres. Nev- ertheless, I regard the corpus callosum, as well as the convolutions necessary to produce an organization fitted for its peculiar functions. This structure, per- haps, has some advantages, as the vegetative func^ 175 tions of the parts are concerned; it may possibly have the same end as the cavities and anfractuosties, of which I shall speak more particuarly by-and-by. With the exception of regarding the corpus cal- losum as an apparatus of union, I see no reason to alter any of the other ideas relative to this mass, published by Dr. Gall and me in our Memoir to the French Institute in 1808, and in the first volume of our large work : I still maintain the proportions be- tween its different parts and diverse cerebral masses ; the dissimilar course of tiie diverging and converg- ing fibres ; the accumulation of fibres at its two ex- tremities, in consequence of the anterior and pos- terior fissures of the hemispheres. The direction of the fibres forming the raphe, will, perhaps, be better explained in the succeeding section, which treats of the communication of the nervous apparatuses. The structure of the raphe appears to be more analogous to that of the fimbriated body, or its slip communi- cating with the fornix, and of the semicircular tape- worm of Haller (tcenia semicircularis.) The idea formed of the folds of the corpus cal- losum, depends on the view that is taken of the mass lengthwise and from above. Anatomists, con- templating it in this way, have imagined that it was folded down upon itself before and behind, in con- sequence of the prolongation of the cavities into the anterior and posterior lobes between the superior and inferior masses of convolutions. The error of classing the fimbriated body and the entire fornix among the apparatuses of union is evi- dent To be convinced of the mistake, it is enough 176 to remember the direction of the fibres composing these parts. The bundles of neither ever cross the median line; they always run into lateral masses, and are undoubtedly instruments of communication. In the mammalia there lies a band upon the medulla oblongata behind the annular protuberance, which Dr. Gall and I have regarded as a commissure of the auditory nerves. Our view, in this particular, may be disputed, and I leave the point still undetermined. The band, however, is certainly in connexion with the auditory nerves. Let us now treat of the undoubted fibres of union, or of the true commissures. And, first, the nervous masses of the vertebral column are connected in the median line by a peculiar order of fibres. (PL i. fig. 6. a.) In the fourth ventricle of fishes, especially of those in which the lateral edges of this cavity re- semble ganglions, certain transverse fibres may be distinctly seen behind and before the median gang- lion and uniting the two cerebral halves. (PL ii. fig. 14, e,e.) I am much inclined to think that the nervous in- struments are principally connected at their origins. The two halves of the cerebellum of all vertebral animals, for instance, are united by transverse fibres running between the two primary bundles that come from the sides of the medulla oblongata. In the sturgeon, frog, (pi. iii. fig. 2,) and other fishes, and reptiles, where the cerebellum is so small, there is a thin white slip which joins the two sides together. In other fishes (pi. ii. fig. 13,) and reptiles, whose 177 cerebellum is larger, as also in birds, we may per- ceive a white layer at the bottom of the cerebellar ventricle, terminated in birds at its anterior edge by a small tubercle. (PL iii. fig. 8, 43.) A similar apparatus is found in man, and in all mammiferous animals. The cerebellum is at a greater or smaller distance from the bigeminal or quadrigeminal bodies. This accounts for the different lengths of the part styled valve of Vieussens, which consists of a thin slip of fibres running transversely between the cerebellum, the edges of the primary bundles that expand into the organs of the affective faculties, and the bigemi- nal or quadrigeminal bodies. (PL xi. fig. 1, y.) To show the interior of the fourth ventricle, the union of the two cerebellar hemispheres, and the Vieussenian valve in man and the mammalia, the brain must be laid on its superior surface (pi. vi. fig. 1,) the annular protuberance and medulla oblongata separated, and the two halves pushed aside. In fishes there is scarcely a part analogous to the valve of Vieussens. This happens from the vicinity of the cerebellum and the other ganglions. In birds, however, the part is very distinct. (PL iii- fig- 6, and pi. xi. fig. 3, y.) Behind the bigeminal bodies in birds (pi. xi. fig. 3,) and the quadrigeminal bodies in the mammalia and man (pi. xi. fig. 1,) at the point where the nerve of the superior oblique eye-muscles goes off (ibid. 13,) there is a transverse uniting band. The bigeminal or quadrigeminal bodies are always united by commissures or transverse bands. (PL m. 23 178 fig. 6, and pi. xi. fig.l, 2,3, x.) The body called pineal gland is always found in animals possessed of the great inferior ganglion of the brain (thalamus.) I do not believe that it occurs among fishes. M. Tiedemann entertains the same opinion; but M. Serres * declares, that the pineal gland is to be de- monstrated in all the four classes of vertebral ani- mals. According to him, the body has two sets of peduncles, one issuing from the optic thalamus, another from the quadrigeminal tubercles. He, however, is in evident contradiction with himself when he adds, that the thalamus does not exist in fishes. Anatomists now-a-days are agreed as to the part in question being no gland, but a nervous mass com- posed of w.hite and cineritious substance. Its form and size vary extremely in different classes of ani- mals, It always lies between the true optic and the great inferior ganglions of the brain. It has four connecting slips, two on each side. The posterior pair run backwards and downwards, and adhere to the proper ganglions of the optic nerves, (PL vii. fig. 2, and pi. x. fig. 1, B. s.) It is at the fore-part of the pineal gland that the granular concretions which have attracted so much notice are principally found. Malacarne! says, that he has seen them in the pineal gland of a goat, and Soemmering, J that he has detected them in that of a fallow deer. * Rapport, &c, p. 69, 70. fEncephalotomia di alcuni Quadrupedi, Mautua, 1795. $ Vom Him und Ruckenmark, Maynz, 1788. 179 Des Cartes is generally known to have considered the pineal gland as the seat of the soul. At the present day, it were'useless to repeat the arguments that Steno * has employed against the Cartesians in refutation of their error. 1 only speak of the pineal gland in this place for the sake of connexion, for it appears to belong, at least, as much to the instruments of communication as to those of union. The part which, by anatomists, is entitled poste- rior commissure, is found lying anteriorly to the proper optic ganglion, and at the commencement of the great inferior ganglion of the brain, into which it plunges immediately. (PL iii. fig. 9, pi. vii. fig. 2, and pi. xi. fig. 1, v.) The transverse fibres, usually termed the soft or middle commissure, may be readily seen extending between the great inferior cerebral ganglions in the mammalia. (PL xi. fig. 1, 46.) Many authors have doubted the existence of this part in man. It may unquestionably be demonstrated in the human brain ; but its very delicate fibres areteasily torn, and care is required in the attempt to point it out. But it may be most readily shown from below by separa- ting the crura, the annular protuberance, and the medulla oblongata. 1 now come to a commissure that is quite constant in all vertebral animals. In man, it is called the anterior commissure. Its regular occurrence, like that of the posterior commissure and uniting fibres * Discourse on the Anatomy of the Brain, inserted in Winslow's Anatomy. 180 of the quadrigeminal or bigeminal bodies, is an index of its importance. In the eel, (pi. ii. fig. 1,) and barbel, (ib. figs. 12 and 13,) it lies between the second pair of ganglions, beginning the reckoning from before (ib. fig. 13, 61 ;) in the flounder, (ib. fig. 4,) the roach, (ib. fig. 11,) and others, it is situa- ted between the olfactory ganglions. In all the ani- mals possessed of striated bodies, viz. reptiles, birds, and the mammalia, it always lies anteriorly to the junction of the optic nerves. It traverses the stria- ted bodies, and is continued onwards between the anterior and middle lobes. (PL iii. figs. 6 and 9; pi. viii. figs. 1 and 2, and pi. xi. figs. 1 and 2, 61.) In all the mammalia, the anterior commissure is composed of two parts : the one of these communi- cates with the olfactory nerve, the other, as in man, is prolonged towards the fissure of Sylvius between the anterior and middle lobes. This discovery I published in the spring of 1821, in a thesis, entitled Encephalotomie* The portion running to the olfactory nerve forms an arc, the convexity of which is turned backwards, the concavity forwards. (PL iv. fig. 4, 31.) In man, the anterior commissure traverses the exterior half of the striated bodies : it communicates first with the innermost convolutions of the anterior lobes; then with those situated at the bottom of the Sylvian fissure; and lastly, with those in the fore part of the middle lobe. Is thus forms an arc, whose longest and concave edge is directed backwards. (PL viii. fig. 2, 61.) *Vide p. 23. 181 M. Chaussier* and M. Tiedemann,! regard the anterior commissure as a continuation of the cere- bral crura. Anatomy exposes this error. Having laid the brain on its superior surface, (pi. vi. fig, 1, and pi. viii. fig. 2,) turn back the optic nerves and separate the hemispheres slightly, a white cord about the thickness of a writing-pen will be brought into view. Remove the superimposed parts without im- plicating the anterior commissure itself, and its pas- sage across the striated bodies will be distinctly perceived. Arrived at the anterior extremity of the middle lobes, the anterior commissure divides into a greater number of filaments that communicate with the convolutions. I shall bring this section to a close, by proposing the following question : — Is the anterior commissure proportionate to the cerebral masses destined to the intellectual faculties ? * Anatomie du Cerveau, p. 71. t Op. cit., p. 138. 182 Section VIII. Of the Communications of the Nervous Apparatuses. Thus far advanced, we have seen that the nervous system is an aggregation of organs performing special functions; that the instruments of phrenic life exist in pairs, and that there is a particular structure, by which congenerate parts are united. Another es- sential consideration refers to the communication with each other of the peculiar nervous apparatuses, an arrangement which is indispensable to account for the mutual influence, or, as it is termed, the sympa- thies of the functions. The functions of the thoracic and abdominal vis- cera are evidently mutually influential, and the nerves of vegetative life, generally, communicate together. Again, vegetative and phrenic life are mutually re- lated ; imperfect digestion, for example, disturbs the intellectual energies, and excessive mental applica- tion, or moral sadness, interrupts the process of di- gestion. The communications between the nerves of the thorax and abdomen, and the anterior roots of the spinal and cranial nerves, especially the pneumogas- tric, the hypoglossal, the abductor, the facial, and the trigeminal, are well known anatomical facts. Further, the spinal nerves are intimately con- nected with each other : there are longitudinal bands that run along the edges of the two fissures of the spinal cord ; these are, especially, evident on the dorsal aspect of the cervical portion (pi. i. fig. 5,) 183 and on each side, at the bottom of the dorsal fissure. (PL i. fig. 7.) The nerves of voluntary motion and of sensation are also most intimately connected. Moreover, the nerves of motion, of general sensa- tion, and of the various special sensations, taste, smell, hearing, and sight, communicate with each other. The mutual influence of the organs of motion, of the external senses, and of the affective and intellec- tual faculties, equally require an organic communi- cation. The physiological experiments or mutila- tions which have been made in reference to this subject, are not, by any means, satisfactory. The cerebellum, which, according to M. Rolando, gives the locomotive power, and to M. Flourens, regulates the motions, is in more intimate connexion with the dorsal than with the abdominal roots of the spinal nerves; yet M. Magendie has been led to conclude that the dorsal roots of these nerves preside over sensation, whilst the abdominal are the special or- gans of motion. It is, however, certain that the external senses and the organs of motion, aid, to a greater or less amount, the cerebral functions, properly f.:> called. It is to this end, consequently, that the ner- vous masses of motion, and those of general and special sensation, communicate with the organs of the affec- tive and intellectual faculties. This communication is established by means of the medulla oblongata, the de- cussation of some of whose component bundles, ex- plains the effects of cerebral injuries being frequently manifested on the side of the body opposite to that on which they occur. 184 The sense of taste is subservient to the functions of digestion and nutrition ; and its instrument is a branch of the trigeminal, a nerve of general sensation, supplying the organs of mastication, and arising very nearly from the same place as the glossopharyngeal, the pneumogastric, and the facial. The auditory nerve embraces the primary bundles of the organs of the affective powers, and these it assists more generally, especially among animals, than those of the intellectual faculties: males and females call on each other as the season rof love draws near ; the cries of the young bring the mother to their aid; the barking of the dog, the grunting of the hog, the crying of the monkey, collect other individuals of their several kinds to render assist- ance ; all the animals that plant sentinels, know the sounds of alarm ; and the courage,* secretiveness, or circumspection! of many species is excited by pe- culiar tones, appreciated by the sense of hearing. The cock taunts his adversary by crowing; the sparrow, turkey, common fowl, and many other kinds of birds advise their young of an enemy's ap- proach, and by their cries admonish them to keep quiet, or to seek security by flight. The optic nerve aids almost all the affective and intellectual faculties. Instead of running directly from its origin to the^eye, it therefore^ turns out- wardly, and in its course, communicates with all the parts adjacent, from its ganglion, onwards, to the tuber cinereum; so that in order to turn] it back in man, it must be torn away from a thin communi- * Combativeness, of the new nomenclature. f Caution. 185 eating layer all the way along its outer edge as far as the external geniculated body. Phrenology shows that vision assists more immediately those organs sit- uated backwardly, laterally, and anteriorly, than those in the middle line of the head, such as veneration, (reverence,) firmness, hope, justice, conscientious- ness, &c. In all animals, the optic nerve is evidently connected with a great number of cerebral masses. The nerve of smell always communicates with the anterior cerebral lobes, and in animals this sense aids in a very particular manner the faculties that take cog- nizance of external objects, their qualities, their rela- tions, and the phenomena they present. Animals examine their food, their friends, their enemies, their dwellings, &c, &c, by means of smell. The olfactory nerve also communicates with the anterior convolutions of the middle lobes, especially with the part that corresponds to the hippocampus's foot, or the amnions' horn. If there be a cerebral part presiding over the functions of hunger and thirst, it would appear to be situated in this neighborhood. I am confirmed in this supposition by the vicinity of the organ of destructiveness. To conclude, — nature has taken great pains to es- tablish an intimate connexion between the different cerebral parts themselves. Two longitudinal bands, running at the bottom of the dorsal fissure of the spi- nal cord, are continued into the fourth ventricle. In fishes they run as far as the olfactory ganglions. (PL ii. fig. 13.) The cerebellum, as I have already shown, always 24 186 communicates with the medulla oblongata, and the bigeminal or quadrigeminal bodies. The parts successively added to form the cerebral hemispheres are connected together by transverse bands or interlacing fibres. A band of this nature is sometimes seen below the olivary bodies. (PL viii. fig. 2, 64.) Different other transverse interlacements are visible in every human brain that is moderately consistent, 1st, at the superior edge of the annular protuberance (pi. viii. fig. 1, 33;) 2ndly, in the mid- dle of the cerebral crura (pi. vi. fig. and 1, pi. viii. fig. 1, 34 ;) 3rdly, below the optic nerve (ib. fig. 1, 35 ;) 4thly, at the place where the fibres issue to enter the superior convolutions of the middle lobe (pi. viii. fig. 1,36;) 5thly, between the two great cerebral ganglions) ibid. 37 ;) 6thly, at the external edge of the striated bodies (pi. viii. fig. 1, and pi. ix. fig. 1, 38.) These interlacing bundles do not occur on the external surfaces only, they also penetrate the interior of the masses to which they belong. The greater part of the fornix, that is to say, the fimbriated bodies running from the hippocampus's foot, the posterior and anterior pillars, and the lon- gitudinal fibres between them, as also the mammil- iary bodies and their prolongations, are evidently apparatuses of communication. (PL x. fig. 1, B. 57 — 62.) The anterior pillars of the fornix traverse the tuber cinereum, and plunge into the mammiliary bodies, from whence another bundle issues, to be lost in the great ganglion of the organs of the affec- tive faculties (thalami.) (PL x. fig. 1, 16.) In the mammalia the fornix further communicates with 187 the two longitudinal bands of the corpus callo- sum (raphe,) and with the septum lucidum, which last in its turn communicates with the raphe, and with a band lying before the optic nerves. (Ibid. 57, 58, 59.) The raphe itself, and also the semicircu- lar tape-worm of Haller (pi. xi. fig. 1, A. 32,) ap- pear to be instruments of contmunication, the first between the converging fibres themselves, the other between the great cerebral ganglions and the converging fibres. These parts are strikingly analogous in all the mam- malia. In birds and reptiles there are fibres, which, from the middle lobes, the circumference of the pos- terior lobes, and from the median line, come together towards the base of the brain, and form a bundle that communicates with the cerebral crura behind the optic nerves. This fibrous layer, or bundle of birds, consequently, resembles the fornix and septum lucidum of mammalia. (PL iii. fig. 6 ; and pi. xi. fig. 3, B. 60.) In fishes, besides the two longitudinal bands that run the whole length of the encephalic masses, each ganglion sends a slip of communication to its neighbor, the cerebellum to the optic ganglion, this to the succeeding one, and so on successively, whilst the most anterior of all sends fibres to join the com- mon longitudinal band of the olfactory nerves. (PL ii.fig. 13.) The mass entitled infundibulum lies behind the junction of the optic nerves. It is evidently travers- ed by white filaments, and communicates with the tuber cinereum. (PL ii. fig. 4, 6, 8 ; pi. iii. fig. 12 ; and pi. vi. fig. 1, 17.) 188 The influence of the anterior pyramidal bodies, on the propagation of the will towards the instruments of motion, deserves some attention. According to phrenological observations, the anterior lobes of the brain contain the organs of the perceptive and reflec- tive intellectual faculties, without which there would be no will.* Now these lobes are intimately connect- ed with the pyramidal bodies, and these last commu- nicate directly with the abdominal half of the spinal cord, whence, as it appears, the nerves especially appropriated to propagate the will are detached. Lastly, in the animals whose brains are smooth on the surface, the peripheral connexion of the individ- ual organs is manifest; in the other kinds, whose brains are convoluted, it is extremely interesting to trace the connexion of the different cerebral masses composing special instruments. These connexions ex- plain the mutual influence of the faculties. The or- gans of analogous powers are regularly in each other's vicinity; the convolutions that compose them even run into each other. The organ of philoprogenitiveness communicates with that of inhabitiveness, and with that of courage (combativeness ;) the organ of cour- age also communicates with that of attachment (ad- hesivenesss ;) and with that of destructiveness ; the organ of secretiveness communicates immediately with that of destructiveness, and with that of circum- spection (caution ;) the organ of benevolence com- municates with the organ of veneration (reverence) ; the organ of firmness is in communication with those of all the faculties around it—veneration, justice, * See Philosophical Principles of Phrenology, Lond. 1325, p. 32. 189 and self-esteem ; the organ of justice runsinto that of the love of acquiring (acquisitiveness) — this is con- nected with that of construction (constructiveness) ; the organs of the perceptive faculties are all linked together, as are those of the reflective powers in like manner ; the organ of artificial language is placed across the organs of the intellectual faculties gener- ally. Thus, the especial pains which nature has taken to establish communications between the cere- bral parts cannot be overlooked ; and, as I have al- ready said, it is this arrangement that enables us to understand the mutual influence of their respective functions. 190 Section IX. Of the Anatomico-Physiological Relations of the Nervous Apparatuses. In Phrenology it is an admitted axiom, that structure does not reveal function ; still, it is certain that there is a relation between the organic structure of an ap- paratus and its functions. Many considerations bear- ing upon this point are contained in the works which Dr. Gall and I have published conjointly as well as severally. In this place it will be enough merely to refresh the reader's memory. No affective or intellectual function is ever mani- fested without a brain ; and these functions appear simultaneously with the brain; this organ is in the first instance pulpy, it increases in growth, becomes fibrous and advances gradually to its maturity; but, after the meridian of life has been passed, it shrinks again, and the convolutions become less plump, and seem less firmly packed than in youth and manhood's prime. The nerves also decrease in old age. The cerebral fibres in declining years acquire density and firmness, but they lose in specific gravity. In con- formity with these facts, the mental faculties of newly- born children are confined to voluntary motion, to the sensation of hunger, and to some obscure feelings of pain; by slow degrees the functions of the exter- nal senses become perfect; the child begins to attend to outward objects, to act upon these, to manifest determinate desires and clear notions: it becomes 191 in succession boy, youth, and man, when the faculties show themselves in their utmost energy : little by little they now begin to lose strength, and old age is at length marked by blunted sensibilities, and enfee- bled intellectual powers. A defective development of the brain prevents the exhibition of affective and intellectual faculties, and causes idiotism. Men of great and general abilities have always a voluminous brain. Different cerebral parts are differently de- veloped in the two sexes, in different nations, and in different individuals of the same people. The cerebral organization is often times alike in several members of a family. In all these cases it is easy to prove a relation between the condition of the brain and the affective and intellectual manifestations. The brains of different species of animals vary in density, in texture, and probably in their general organic constitution. This is the reason why func- tions essentially similar offer so many modifications, and never correspond in degree of energy with that of the development of their instruments : that is to say, the affective and intellectual aptitudes cannot be measured by the absolute size of their organic appa- ratuses. Size, however, is one condition essential to energy ; and, other conditions beingequal, the largest organs will show the greatest vigor. It would appear that, in conformity with the law established in regard to electrical phenomena, the energy of nervous apparatuses depends in a great measure on their quantity of surface ; more on this, perhaps, than on their component quantity of nervous matter. M. Desmoulins, in his Memoir to the Acad- 192 emy of Sciences of Paris, attempts to prove, 1st, that integrity of surface is the only constant condition for the production of nervous actions ; 2nd, that the in- tensity and perfection of nervous actions depend on the proportionate extent of nervous surfaces ; and 3rd, that the nervous actions are performed and transmitted by the surface. I do not mean to say that the quantity of a nervous apparatus has no influence on the energy of its func- tions ; but the influence of the peripheral expansion is certainly great. May it be, on this account, that the cerebral apparatuses are hollow or lamellated? In the inferior classes of animals, the nervous mass- es are very commonly hollow. Cavities and anfractuosities unquestionably in- crease the surface of organs. Have the annular pro- tuberance and corpus callosum of man and the mam- malia a like destination? The cavities and convo- lutions also facilitate the circulation of the blood, and thus appear to produce twofold good effects. Let us turn, then, and examine the cerebral cavi- ties and their communications. The common num- ber of cavities reckoned is four. The fourth is formed by the separation between the cerebellum and the medulla oblongata. (PL ii. fig. 13; pi. vii. fig. 2; pi. x. fig. 1; pi. xi. figs. 1 and 3, m.) The di- mensions and development of the fourth ventricle, says M. Desmoulins, coincides with the development of the eighth pair of nerves. Now to nic the fourth ventricle seems nothing in itself, and not at all proportionate either to the cerebellum, or the eighth pair of nerves. It, in fact, depends entirely for its size on the united 193 breadth of the medulla oblongata and development of the cerebellum. Is the cerebellum broad and the medulla oblongata narrow, the fourth ventricle will be narrower than it would have been, were the me- dulla and cerebellum both broad. In the sturgeon, frog, toad, &c, the fourth ventricle is of considera- ble magnitude, and the cerebellum very small. The fourth ventricle runs between the annular protuberance and valve of Vieussens on to the aque- duct of Sylvius, or canal between the crura of the brain and the commissure of the quadrigeminal bodies. (PL vii. fig. 2, ; vm\-c /; hu Utcn'sltithog* 'Boyt. :pz jrz ft w Fig :i Fuh.bv AJarsli. Capen A' Z> < Hcndle.torisI.ibh. Bos-ton *7 APPENDIX to the ANATOMY OF THE BRAIN: CONTAININQ A PAPER READ BEFORE THE ROYAL SOCIETY ON THE 14TH OF MAY, 1829, AND SOME REMARKS ON MR. CHARLES BELL'S ANIMADVERSIONS ON PHRENOLOGY. WITH SEVEN LITHOGRAPHIC PLATES. By J. G. SPURZHEIM. 28 PREFACE. Richard Chenevix, Esq., who died too soon for science and friendship, during his last stay in England, desired me to give hiin a Paper on any point of Phrenology, proper to be presented to the Royal So- ciety of London. I complied with his wish, in or- der to try the wisdom of that learned body, and my lamented friend delivered the following Paper to one of the Secretaries, who read it to the Society on the 14th of May, 1829, but declared that it could not be printed in the Transactions of the Society, because it did not contain any new matter. I grant that its general principles — the plurality of organs — prevails in the joint publications of Dr. Gall and myself, as well as in my work on the Anatomy of the Brain ; but the specifications of the particular cerebral portions, 1st, in the ordinary state of the Human Brain —2dly, in the Brain of an Idiot — 3dly, in the Brain of the Ourang-outang, cannot be found in our works, since Dr. Gall died without knowing those points, and I did not know them when I published my work on the Anatomy of the Brain, in 1825. My former manner of marking the organs on the external surface of the head (seethe Phreno- logical Busts,) compared with the new delineation, is^an evident proof of this truth: formerly I indicat- 220 PREFACE. ed the situation of all, but the limits only of a few organs, whilst the actual delineation corresponds not only with the situation of the organs, but also with their limits and configuration. This additional dis- covery was desirable — nay, indispensable — to out- other anatomical discoveries and publications in con- nexion with the Physiology and Pathology of the Brain. On the other hand, the Transactions of the Royal Society contain many new illustrations of known principles, whilst none of their volumes give the views contained in my Paper on the Brain in the ordinary state, in the state of Idiotism, and on the Brain of the Ourang-outang. It is, however, con- ceivable that the Secretary, who never ceased to be hostile to Phrenology, found, as he said, that my ideas require a great imagination to be admitted, and objected to their being printed in the Philosophical Transactions. My friend Chenevix, in order not to have a formal refusal, withdrew the Paper. The adversaries of Phrenology may not appreciate, per- haps not even understand, the principles and ideas of my Paper ; but those who take interest in the most important part of Anthropology will appreciate them, as the completion of the Phrenological Anat- omy of the Brain. I publish the Paper without the least alteration. I profit of this opportunity to make a few remarks on Mr. Charles Bell's animadversions on Phrenology, and rely throughout on truth and on the justice of public judgment. J. G. Spurzheim. APPENDIX. On the Brain, as an Aggregation of Parts. The slow progress of human understanding is per- ceptible in all branches of knowledge, but it is par- ticularly striking in the doctrine of the nervous sys- tem. It is not yet long ago that, however strange it may appear, the brain was classed along with the viscera of the abdomen and thorax, and its structure treated of in the Splanchnologia, though at the same time it was considered as the origin of the nerves of the whole body. The old error, too, that the ner- vous system is composed of similar parts, and can be compared with a net, prevailed till lately, though it may be refuted by anatomical, physiological and pa- thological facts, and though several ancient anato- mists, particularly Erasistratus and Gaienus, had al- ready perceived the light of truth. It, however, was reserved to modern anatomists to establish sounder notions of the structure and functions of the ner- vous system in general, and of the brain in particu- lar. The brain and nervous apparatus are now placed together in one system. Proofs, founded on com- parative and human anatomy, are quoted to show that the nervous masses are different, and that the 222 APPENDIX. brain, spinal cord, and nerves of the vegetative func- tions, cannot be confounded with each other. Not only divisions, but even subdivisions of the individ- ual portions, are admitted. Winslow, Johnson, and Bichat, not only separated the great sympathetic from the spinal cord and brain, but considered it also as an aggregation of nerves, or as a suit of communi- cations between different nervous centrc.-s, situated at various distances from each other, and destined to separate functions. The physiological experiments of Mr. Charles Bell and of M. Magendie leave no doubt of the nerves of sensation and of voluntary motion being different. Mr. Charles Bell speaks of peculiar nerves of respiration, and of six sorts of nerves in the organ of sight. Three sorts of nerves go to the tongue, and the difference of the nerves of the five external senses is generally known. Thus, the difference and necessary subdivision of the nerves of the thorax and abdomen, of the spinal cord and of the external senses, is admitted ; but the error, to consider the brain as a unity, is still pretty common, though it also may be refuted by anatomical, physio- logical and pathological facts, and though it has al- ready been pointed out by several intelligent authors. In order to bring the doctrine of the brain in harmony with the rest of the nervous system, the following remarks are proposed for consideration ; and this object being the foundation of the most important part of Anthropology, deserves the attention not only of the medical profession, but of all thinking classes. I cannot help beginning my remarks with stating APPENDIX. 223 the singular fact, that many physicians, and even some anatomists, who believe in the plurality of the nervous apparatuses adapted to the various nervous functions of the body, continue to contend for the unity of the cerebral mass. However, the plurality of the nervous apparatuses of the abdomen, thorax, spine, and external senses, might invite them to think it probable that the brain too is an aggregation of parts, destined to different functions, and brought into communication with each other, particularly as the brain is simple in the lower animals, and marked by additions and amplifications of parts in proportion as the animal functions become complicated, till in the human brain we find parts of which animals are destitute, in the same way as the nervous apparatus- es of the vegetative functions and external senses become numerous and complicated in proportion to the functions themselves. The close examination of this object, in order to be satisfactory, is to be conducted with anatomical, physiological and pathological views, and by bringing these three sorts of observations into harmony. Anatomical investigations alone are not sufficient to show the difference of the nervous masses, and they alone cannot be relied on. Physiology and patholo- gy must be called upon, as better means of deciding the question. Anatomy alone, for instance, cannot decide which nerves are destined to sensation, and which to voluntary motion ; but these two sorts of nerves are ascertained by physiology and pathology. The difference of the olfactory nerve, within the head of fishes, birds, carnivorous and herbivorous 224 APPENDIX. animals, and monkeys, is so great, that without the external apparatus and without the function of this nerve being known, it would not be taken for the same nerve. Thus, whether the nerves in their ap- pearance are similar or dissimilar in different animals, they are considered as similar, if their functions be such, — and as dissimilar, if this be the case with their functions. The brain has hitherto been treated, with respect to anatomy, physiology, and pathology, in a different way from the rest of the nervous system ; and it has the same fate as to its comparative anatomy, and as to the plurality of its constituent parts. The human brain is taken as the type of comparison ; and, in dif- ferent animals, individual cerebral parts are admitted or denied, according to their similar or dissimilar ap- pearances of form, situation, and connexion. This proceeding, however, should not be relied on in the anatomy of the brain, any more than in that of the nervous system, and it will be changed as soon as the cerebral functions shall be known. In order not to extend this Paper too much, I shall confine myself to mere anatomical points, which may prepare such physiological aud pathological discussions as cannot be indifferent to those who delight in philosophical inquiries. The human brain is divided into cerebellum and brain proper, and the brain proper is subdivided into two halves called hemispheres, and each hemisphere into three lobes — anterior, middle, and posterior. This division and subdivision may be admitted in birds and mammiferous animals. Some anatomists, however, APPENDIX. 225 fuse the posterior lobes to the greater number of mammiferous animals. Their reason is, because the cerebellum is not covered by the brain, as in man and monkeys. But this manner of judging is evi- dently erroneous, even from mere anatomical consid- erations. If the posterior lobes were wanting when- ever the cerebellum is not covered by the brain, the anterior lobes might be said to be wanting also each time the bulb of the olfactory nerve is not covered by the brain in the way that it is in monkeys and in man. Various appearances in the nervous system are explained by the the horizontal position of ani- mals and the vertical station of man. The spinal nerves, for instance, of the mammiferous animals go off from the spinal cord in a horizontal direction, whilst in man they run from above downward before they pass through the dura mater. The medulla oblongata has a horizontal position in animals, and a vertical one in man. The great occipital hole, too, has a different position in animals and man. Now, if these and various other modifications of appearance be accounted for by the different position of man and animals, shall this cause not extend its influence over the appearances of the cerebral parts ? The eyes are not wanting in birds, and in the greater number of the mammiferous animals, because they are placed laterally in their heads, whilst in man and monkeys they are situated in the face : in the same way the posterior lobes may exist, though they lie before the cerebellum. The internal structure of the posterior lobes fur- nishes a surer proof of their existence than their ex- 29 226 APPENDIX. ternal appearance. In man they are evidently com- posed of bundles which come from the pretended op- tic thalami. Now, these very ganglions exist in the mammiferous animals as well as in man, and bun- dles run out of them towards the posterior convolu- tions of the brain. This analogy of structure allows us to conclude upon similarity of parts, and this con- clusion is put beyond doubt by observing instincts in animals which resemble certain feelings in man, the manifestations of which take place by the posterior lobes of his brain. It is a difficult matter to decide about the exist- ence or want of individual parts in the brains of man and animals. What is of the greatest importance is, not to confound the essence or existence of a special apparatus with its more or less complicated state, since a portion which amplifies its structure may be wanting in certain animals, which, however, possess the apparatus of the special function, but in a more simple state. The intestinal canal, in different ani- mals, is simple, or more or less complicated. Pigs, dogs, cats, etc., as well as the ruminantia, have a stomach, — though in the former it is simple, and in the latter complicated. Birds, as well as mammif- erous animals, have a cerebellum and hemispheres of brain; but the cerebellum of birds has no pons, and their hemispheres no corpus callosum. It was a great error to take the general type of brains in a class of animals as the criterion of the existence of in- dividual parts. The corpus callosum, for instance, the pons, etc., have been taken as parts for them- selves, whilst they are mere complications of indi- vidual cerebral apparatuses. APPENDIX. 227 It is remarkable that the brains, though they are more or less complicated, preserve a common type in each class and in each genus of animals. In various animals, for instance, each portion of their brains is formed in a similar way, ends at the surface in one or several convolutions, and has fibres which run to- wards the middle line, and contribute to make up what is called corpus callosum ; but it was wrong to take the corpus callosum as a part for itself, whilst it contains merely portions of as many apparatuses as the hemispheres are composed of. The corpus cal- losum, then, is a mere indication that the special parts of the hemispheres of various animals are built according to a common type. But the general type of brains may be analogous, though the special appa- ratuses destined to individual functions may vary in number and size. Various brains may present three lobes, convolutions, a corpus callosum, a fornix with its appendices, four cavities—and yet the special parts which make up the whole of their brains may be different in number, size and quality, whilst their general form of structure alone is similar. ' Thus the old error in question, committed by our contemporaries, as well as predecessors, must be abandoned, and the comparative anatomy of the brain must be treated as that of all other systems of organ- ization. After these general remarks, I shall examine m par- ticular — 1st, Whether in the Human Brain individ- ual parts destined to special functions may be point- ed out, though they are in the most intimate connex- ion with each other - 2dly, Whether it can be shown 228 APPENDIX. that in Brains of Idiots certain parts are defective, or even wanting.— and, 3dly, Whether the Brain of the ourang-outang and the human brain, which have the greatest analogy with each other, are composed of the same parts. I. The Parts of the Human Brain in the ordinary state of health are essentially the same, and only modified in size and quality. Let it be kept in mind that a true division of the nervous system in general, and of the brain in par- ticular, can be established only by the functions per- formed. The general form, direction, and connex- ion of the convolutions, however, prove the regular- ity of the essential part of the human brain, and it is certain that individual portions may be pointed out. This anatomical regularity is evident and partic- ularly striking at the basis of the brain. The pos- terior convolution, for instance, of the basis of the anterior lobes is always transverse; — four cerebral portions meet at the external roots of the olfactory nerve ; the convolutions in the middle are longitudi- nal. A similar direction is perceptible in the convo- lutions of the middle lobe, etc. — As the appearance of the convolutions at the upper surface seems less regular, I give a drawing taken from a human brain, in order to exemplify my assertions, and to show the individual portions which may be seen in the ordinary state, whilst their modifications concern their size and their greater or smaller number of lateral inden- tations and depressions on the surface of the convo- APPENDIX. 229 lutions. These modificuations exist not only in the brains of different persons, but on both sides of the same brain, as may be seen in the drawing before us (PL I.), where the cerebral parts are reduced in size, but where proportions and configurations are preserv- ed. Vjews of the brain, from its basis and in profile, are easily found in various anatomical publications. The posterior extremity of the hemispheres is composed of several convolutions running in the di- rection towards the apex, a. Now, this portion be- tween a and b is always distinct and separated from the following portion by a deep anfractuosity at b. Between b and c is another portion, composed of several convolutions distinguishable in every ordina- ry brain. No anatomist, for instance, can be mis- taken in looking for the convolution marked 10. Between c and d lie always two convolutions, 16 and 17, which run laterally towards the cerebral por- tion 18, situated under the anterior inferior angle of the parietal bone. The convolution marked 16 was in this brain larger on the left than on the right side ; but its lateral appearance, though modified on both sides, is essentially the same. The portion 14, between d and e, is commonly, as in this case, separated from the lateral parts; but sometimes, on one or the other side, or on both sides, it is in connexion with the portion marked 18. Between e and / is a longitudinal portion, 13, sometimes separated from the lateral convolution marked 21 on the right side, and sometimes connect- ed with it, as on the left side. Farther, the portions marked 18 18, 4, 5, 11, ^ 230 APPENDIX. 12 12, and others deeper situated laterally and in the forehead, may be easily pointed out in the ordinary state ; and in this way the idea of the regularity of the cerebral portions, as to their essential appearance, may be put at rest. If it be objected that the difference of their inter- nal organization cannot be proved by anatomy, I re- peat that which I have already stated with respect to the parts of the spinal cord, or nerves of sensation and voluntary motion; viz. that their difference, too, cannot be proved by anatomy, but that it is admit- ted from physiological proofs. The same will be the case with the cerebral portions. II. In certain Idiots, individual Portions of the Brain are defective, or even wanting. It is evident that a disorder in the internal organ- ization of the brain and its parts may prevent the manifestations of the mind.; but it is also certain that sometimes individual portions of the brain are defective in the development, remain more or less in their embryonic state, or are entirely wanting. Why should this not happen in the cerebral portions, as well as in the nervous apparatuses of the external senses ? There are various cases of monsters on rec- ord, who were deprived of the olfactory or optic nerve ; others are born with imperfect brains. In the Zeitschrift fur Physiologie, published by Tiede- mann and Treviranus, several defective brains of monsters are described and represented. There is one, whose surface is smooth, without convolutions, APPENDIX. 231 as in the lower animals and in the embryo of man. In my work on the Anatomy of the Brain, I gave the figure of the brain of an idiotic girl, who died at Cork in Ireland, in comparison with the brain of an ourang-outang, kept in alcohol in the Garden of Plants at Paris. I lay here by the drawings of such a brain in the possession of Mr. Stanley, by whose kindness I was allowed to take them. There is one view from above, another in profile, and a third from the basis. The natural size of the individual parts is copied, but the parts are not in their natural posi- tion: the medulla oblongata, the cerebellum and the posterior lobes, in particular, are stretched out horizontally backward, because the brain is taken out of the skull. PI. II. presents the upper surface. Being com- pared with the ordinary state (PI. I.), the portion be- tween a and b, and that between b and c are evi- dently defective in their development. The third portion between c and d, is still more so. The por- tions 14, 13, and 21 of the ordinary brain are not distinctly separated from each other, but are mixed together between d and/. The convolutions mark- ecflO and 11 are more regular, whilst those marked 4 12 and 18 are very defective and irregular. ' The same brain in a lateral view (PI. III.) shows a defect in all the lateral parts, but particularly in the anterior portion of the middle lobe, h, and in the whole anterior lobe, between/and g. The portions 4 5 12 16 17, are extremely defective, in compar- ison' wilh the ordinary state; 6, 7, 8, 10, and II are more regular. 232 APPENDIX. In the views from the basis (PI. IV.), the individ- ual masses of the middle lobes are pretty natural; but in the anterior lobes, the most striking differ- ence is observed. The longitudinal anfractuosity, in which commonly the olfactory nerve runs, is scarce- ly indicated by a very small depression, i; the oblique depression, k, corresponds to an anfractuosity which, in the ordinary state, divides the lower surface of the anterior lobes into three portions — posterior, internal, and external. The common subdivisions of these three portions are scarcely perceptible, and their embryonic state is evident. The cerebral mass, situated behind the superciliary ridge, is ex- tremely backward in its development, and several convolutions which elevate the forehead of man are wanting. III. The Brain of the Ourang-outang does not con- tain all the Parts of the Human Brain. It is often said, that the brains of mammiferous animals contain the same parts as those of men ; while the truth is, that their brains are more or less complicated, and that even the brain of the ourang- outang — which, among all other brains, has the greatest analogy with the human brain in its healthy state, and a greater analogy than the brains of many idiots — is yet deprived of several parts. Tyson, who gave a very imperfect figure of the brain of the ourang-outang, was mistaken in finding it quite simi- lar to that of man. M. Tiedemann (Zeitschrift fur APPENDIX, 233 Physiologie, 2 B.) mentions the similarity of the brain of the ourang-outang with that of man as to the cercbell'im, medulla oblongata, pons, crura, cor- pora quadrigemina, optic thalami, corpora striata, corpora candicantia, fornix and its appendices, cor- pus callosum, anterior and posterior commissures ; but he adds, that the brain of the ourang-outang es- sentially differs from that of man — 1st, by its whole mass being smaller, and, 2dly, by its smaller number of convolutions and anfractuosities ; yet he had no idea of the special portions being more defective than in man, and of certain parts being wanting alto- gether. My friend Dr. Leach granted me the permission to make drawings from the brain of an ourang-outang which belongs to him, and is now deposited in the College of Surgeons at London. The three views, from above, in profile, and from the basis, compared with the regular brain of man and with that of the idiot, show at once the analogy, modifications and differences of certain parts, and the entire want of others. The brain being taken out of the skull, its parts changed their natural position, in the same way as the idiotic brain. PI. V. is the view from above. In comparing it with PI. I. and with PI. IL, the portions between a b, b c, and c d, are very similar with PI. I., and more complete'thaninthe idiot, PI. IL The portion mark- ed 14, between d and e, PI. L, is wanting in the ourang-outang ; but the next portion, marked 13, PI. I , between e and/, is quite similar in man and in the ourang-outang. The parts 4, 5, 10, 11, 12, 16, 30 234 APPENDIX. and 17, correspond to similar parts in man ; but about 18 there are several convolutions in man, whilst in the ourang-outang there is only a small cerebral portion, of which it is impossible to say whether it is composed, or not, of different parts. PI. VI. exhibits the ourang-outang's brain in pro- file. There is, again, more analogy with the ordi- nary state of the human brain than with that of the idiot, PI. III. The portions a b, 4, 5, 6, 7, 8 8 8, 12, 16, and 17, correspond with distinct portions in man. In the anterior lobes between / g there is more brain than in the idiot, yet about/there is great want of cerebral mass in comparison with the ordi- nary state of man : 21 seems similar with man, but about 18 again the want of brain is evident. PI. VII. represents the brain of the ourang-outang from the basis. The medulla oblongata, cerebellum, pons, crura, vicinal nerves, and the convolutions of the middle lobes, are quite analogous with those of man. The general division, by the anfractuosity k, into three portions, posterior, internal and external, of the basilar part of the anterior lobes, is visible, as in man ; the internal portion is, proportionately to the others, the largest — the posterior and external are small. The cerebral masses behind the super- ciliary arch are less distinct, and the whole fore- head is much smaller than in the ordinary state of man. The greatest analogy, then, between the brain of man and that of the ourang-outang is in the cerebel- lum, the middle and posterior lobes, and at the up- per surface from behind forward to the two lateral APPENDIX. 235 convolutions included. The greatest difference is evident about the portion of the head which corres- ponds to the fontanel in children, since the portion marked 14 in man (PI. I.) is entirely wanting ; far- ther, about the portion, marked 18, under the upper lateral part of the frontal bone, and in the anterior lobes, particularly along the superciliary ridge, and in the upper part of the forehead. From the preceding anatomical remarks, it fol- lows— 1st, that the brain cannot be considered as a unity ; — 2dly, that individual rubrics of cere- bral portions may be pointed out in man ; — 3dly, that these individual portions may be more or less defective, or entirely wanting ; — 4thly, that the brain of the ourang-outang, notwithstanding its great analogy with the human brain, is deprived of certain parts, whilst others are less developed than in the ordinary state of man ; — Sthly, that the comparative anatomy of the brain must be conducted in the same way as in every other system of organization ; —and finally, that a true division of the cerebral masses can be established only by the assistance of Physiol- ogy and Pathology. The importance of this object is& evident from the delicacy of cerebral organization, and it is proportionate to the eminent functions at- tached to it. I therefore hope my remarks will meet the same attention which is commonly bestowed on investigations concerning other parts of our body, or even inanimate beings. J. G. Spurzheim, M. D. SOME REMARKS ON MR. CHARLES BELL'S ANIMADVERSIONS ON PHRENOLOGY. Charles Bell, Esq., in a Paper on the Nerves of the Orbit, read before the Royal Society of Lon- don, June 19, 1823, printed in the Philosophical Transactions of the Society, vol. cviii. p. 306, at- tacked Phrenology in expressions which the lover of truth will know how to qualify. I was aware of them long ago, and knew that this mighty Professor had reproduced them in 1824, in an octavo volume; but I had hoped that he had changed his mind, after all which has happened since 1825, in Great Britain and Ireland, with respect to Phrenology. But as he has again published his accusations without any ad- ditional note or explanation, in this very year, 1830, in a quarto volume, entitled ' The Nervous System of the Human Body' (pp. 222,) I wish to bring his high-sounding animosity against scientific importa- tions from foreign countries before the court of pub- lic justice. ' The most extravagant departure,' says the learn- ed Professor, * from all the legitimate modes of rea- soning, although still under the color of anatomical obsesvation, is the system of Dr. Gall. It is suffi- APPENDIX. 237 cient to say, that without comprehending the grand divisions of the nervous system, without a notion of the distinct properties of the individual nerves, or having made any distinction of the columns of the spinal marrow — without even having ascertained the difference of cerebrum or cerebellum, — Gall proceeded to describe the brain as composed of many particular and independent organs, and to assign to each the residence of some special faculty. ' When the popularity of those doctrines is consid- ered,' continues the Professor, ' it may easily be conceived how difficult it has been, during their successive importations, to keep my pupils to the ex- amples of our own great countrymen. Surely it is time that the schools of this kingdom should be dis- tinguished from those of other countries. Let us continue to build that structure which has been com- menced on the labors of the Monros and Hunters, and which the undeserved popularity of the Conti- nental system has interrupted.' Professor Bell seems to take his ipse dixit as suffi- cient authority; but jurare in verba magistri is no longer the fashion — he is answerable for his asser- tions, and bound injustice to furnish proofs. Mean- while, I tax him in the same terms which he applied (4to volume, p. 221) to Bichat: ' that he paid too little regard to the opinions that prevailed, often assuming that as a novelty which really was not, and doing injustice to those who had preceded him.' Professor Bell is unjust towards Gall, and to- wards the Continent in general. In my opinion, he beholds the mote that is in his brother's 238 APPENDIX. eye, and does not consider the beam that is in his own. If we consider Bichat's education, and his death at the age of thirty-one years, we shall easily excuse his small proficiency in literature ; but must admire, at the same time, the juvenile fire of his mind, and the vastness of his conceptions. Had Mr. Charles Bell been carried off from the scene of life at that age, it is probable that his name would never have appeared in the annals of science. Far- ther, since he himself is obliged to admit that * the best apology for Bichat's conduct was the condition of his country at the time he lived,' I ask Professor Bell, whether he can make the same apology for his proceeding. How can he maintain, in 1830, (4to volume, p. 9,) that ' nothing more clearly evinced the wrong methods of study prevailing on the Con- tinent, than the acquiescence and approbation with which this system (Bichat's ideas on the ganglions) was received there '? Professor Bell must be aware that many anatomists of the Continent are acquaint- ed with the ganglions of nerves which belong to what Bichat styled the animal life. I confine my- self to quotations from our publications, since he par- ticularly attacks Gall's doctrine ; and our opinions were published long before Professor Bell read his animadversions before the Royal Society. Though Gall and myself considered Bichat as an extraordinary genius, yet, in our work on the Anat- omy of the Nervous System in general, and of the Brain in particular (Paris, 1810,) we contradicted every one of his opinions with which we thought it fit to find fault We declared ourselves in particular APPENDIX. 239 against the ideas which he entertained on the gang- lions. Since Professor Bell complains of the popularity of our doctrines and of their successive importations, it may be sufficient for the general reader to know what I stated in my English work on the Anatomy of the Brain, p. 22, viz. : that the opinion in regard of the ganglions which Johnstone, Bichat, and Reil entertained, is by no means exact; that the gang- lions do not interrupt the reciprocal influence of the brain and the nerves of the spinal cord, and that they appear essential to the structure of the nerves of sensation. Farther, since our doctrines are so popular in Great Britain —since Professor Bell laments their succes- sive importations, how can he accuse Dr. Gall of not comprehending the grand divisions of the nervous system ? Are not divisions and subdivisions of the nervous masses, and the plurality of their functions, the essence of our inquiries from beginning to end ? It seems to me that the principle of division and sub- division of the nervous system is as clearly expressed in our works as Professor Bell is able to do it, and, I may add, with more details than he has done it. In the Preface of our large work on the Anatomy and Physiology of the Nervous System in general, and of the Brain in particular, tome i. p. xxn. (Pans, 1810,) we say —' Ce n'est que lorsque l'Anatomie et la Physiologie seront fondues l'une dans l'autie, que la connaissance du systeme nerveux aura atteint son plus haut degr6 de perfection.' In the Introduc- tion, p. 11, we state - < 11 est evident que le systeme 240 APPENDIX. nerveux n'est pas unique et uniforme, mais qu'il doit etre divise suivant les fonctions principalis, et que chaque division principale doit etre subdivisee suivant les fonctions particulieres.' Among the Anatomical Corollaries (sect. ii. p. 75,) the tenth states—'Les systemes nerveux different entre eux dans leur origine, leur structure, leurcou- leur, et leur fermete.' The fifth Section of the above work is entitled 'De la Difference des Nerfs,' and in p. 128 is the following passage : ' Tous les nerfs different entre eux par la variete de leur configuration. Ainsi les nerfs des sens ne se ressemblent nullement dans leur couleur, leur consistance, leur forme, et leur texture. Souvent les divers filamens du meme nerf sont tres- visiblement dissemblables. Non seulement les dif- ferens systemes nerveux, mais aussi le filet du meme nerf, sortent de differens amas de substance grise placee dans divers endroits...Toutescesparticularites restent les memes dans les memes nerfs ; elles doi- vent done avoir pour cause une difference primitive dans la structure interieure, et etre d'une necessite essentielle pour la diversite des fonctions.' In our Memoir presented to the French Institute in 1808, and in our large work above mentioned, we make four principal divisions of the nervous system, and treat of them in four separate sections. In my work, 'The Physiognomical System of Drs. Gall and Spurzheim,' there is a chapter on the anat- omy of the nervous system. In the Second Edition, 1815, p. 13, I say: 'We are of opinion that the nervous system must be divided and subdivided, and APPENDIX. 241 t'iat each part of these divisions and subdivisions has its peculiar origin.' 1 speak of the common division of the nervous system into four portions.— P. 23: 1 admit a difference between the nerves of motion and those of feeling.' I treat of anatomical, physio- logical and pathological proofs of my opinion. I pos- itively state that ' the same nervous fibres do not go to the muscles and to the skin ;' and conclude (p. 25) that ' the spinal marrow consists of nerves of motion and of feeling, and that the greater number of the pretended cerebral nerves belong to the nerves of motion or feeling. In my English work on the Anatomy of the Brain, with a General View of the Nervous System (Lon- don, 1826,) the second Section, p. 23, is entitled « Division of the Masses composing the Nervous Sys- tem.' I positively state that a true division of the nervous system can only rest on the nature of the functions performed. In the same Section 1 sepa- rate the nervous masses of vegetative life from those of phrenic life, and admit as many kinds of nerves as different offices of the particular viscera. In the third Section I contend for the difference between the nerves of voluntary motion and sensation, and found my opinion on anatomical, physiological and pathological facts; and (p. 29) I refer the reader for similar ideas to my work ' The Physiognomical Sys- tem,' published in 1815, and to my French publica- tion on Phrenology, 1818. I even state that 'in all my Courses of Lectures I have broached similar ideas, and have encouraged those of my auditors whom opportunity favored to enter on the inquiry, 31 242 APPENDIX. and to endeavor to trace the nervous fibres from their peripherical expansions to their origin in the spinal cord. These few quotations from our works are an evi- dent refutation of Professor Bell's inexact assertions. It is quite ridiculous to hear him say that Gall had not even ascertained the difference of cerebrum and ce- rebellum. Dr. Gall, in considering the cerebellum as an organ of a special propensity, could not con- found it with the brain proper, or cerebrum ; and accordingly, in all our anatomical publications, the cerebellum is treated in a particular chapter. Thus Mr. Charles BelTs assertions concerning Gall are incorrect: but supposing them to be cor- rect, his judgment appears still very weak and in- conclusive. Let us suppose, contrary to reality, that Gall and myself had confined ourselves to the brain and its subdivisions : might our observations not be exact, though we were quite ignorant of the rest of the nervous masses ? Professor Bell knows nothing of the brain, neither of its structure nor of its func- tions ; but can I therefore maintain that his ideas on the nerves of voluntary motion and respiration are erroneous ? He finds it difficult (p. 38) to trace the fifth pair of nerves to the corpus restiforme of the medulla oblongata, which I find easy, and which has been published in our works on the Brain since 1808 ; but am I therefore entitled to say that he does not know the functions of the same nerve ? May not the structure and functions of any part of the body be examined and known, whilst those of other parts are unknown ? Nay, may not the structure or func- APPENDIX. 243 tions of the same part be known individually and separately ? Accordingly, Gall might have discover- ed the functions of cerebral portions, without attend- ing to the nerves of the spine or the rest of the body ; in the same way as Professor Bell has discovered the functions of some nerves — for instance, of the fifth pair — without knowing their origin, and without attending to the brain. Professor Bell's self-conceit is evident ; but truth is no prerogative of any country, and the republic of letters and science is acknowledged by all liberal minds. Since he is opposed to the importation of new doctrines into Great Britain, will he also object to his discoveries being exported to foreign countries ? His animosity against Phrenology did not prevent me from mentioning his discoveries in my work on the Anatomy of the Brain. It is my only object to show Professor Bell's erro- neous accusations and envious presumption, other- wise it would be easy to criticize several of his ana- tomical and physiological propositions. What reason, for instance, has he to reckon the medulla oblongata with the spinal cord? Is it true that 'each lateral portion of the spinal marrow contains three tracts or columns, one for voluntary motion, one for sensation, and one for the act of respiration' — (4to volume, p. 23) — and that ' a fasciculus may be traced down the spinal marrow, between the sulci, which give rise to the anterior and posterior roots of the spinal nerves ?' (Ibid. p. 129.) I flatter myself that the doctrine of Phrenology is founded on more solid de- monstrations than Professor Bell's assertions con- 244 APPENDIX. cerning the respiratory column in the spinal marrow. I conclude with Cicero's well-known sentence — ' Opinionum commenta delet dies, naturae judicia confirmat.' J. G. Spurzheim. PI.I PI. II * P.I.JIl PI .IV ^ 1*1 ..V. PL. VI. 1'J.VTI