K A i pi''.'nil..... yw ivi '■■:>' : r >'i I t. W$::' ■ /•fi1.',/' .,j-'.i.'v<',1v,,V',l'-r"'--'- '.-■- <-'■'' '- ■ ' NATIONAL LIBRARY OF ME NLT1 0055^663 3 '/&QZ&ZQZGZ£ZQZQZQZQZQZGZLy03$& Surgeon General's Office c° ■ ■^'ccfocn, N. Ife ?vOQj(JQ>(JOjCQGQ(JQj(j&£-Q Q OjQ^^r^i U.S. NATIONAL LIBRARY OF MEDICINE NLM005598833 T** RETURN TO NATIONAL LIBRARY OF MEDICINE BEFORE LAST DATE SHOWN AUG f3 1986 THE CEREBRAL CONVOLUTIONS OF MAX, REPRESENTED ACCORDING TO ORIGINAL OBSERVATIONS, ESPECIALLY UP OX THEIR DEVELOPMEXT IX THE ICETUS. INTENDED FOE THE USE OF PHYSICIANS. BY ALEXANDER ECKER, PE0FE3SOE OF ANATOMY AND CO.MPAEATIVE ANATO.MT IN THE UNIYEBSITY OF FEEIBUEG, BADEN. TRANSLATED BY ROBERT T. EDES, M. D. ™ Li; TjfEW YORK: D. APPLETON & COMPANY, 549 & 551 BROADWAY. 1873. hh^nja- 5/3 1873^ 5/3/, Entsrep, according to Act of Congress, in the year 1373, by D. APPLETON & COMPANY, In the Office of the Librarian of Congress, at Washington. PREFACE. The great problem of an organology of the cere- bral surface, that is, of an anatomico-physiological knowledge of the psychical brain-organs, rests in great part in the hands of physicians : only by accu- rate observations of patients, in connection with the most careful autopsies, can we gradually arrive at some knowledge of the physiological meaning of the single convolutions upon the cerebral surface. There are numerous difficulties which stand in the way of a solution of this problem; not the least of which is that which lies in the study of the con- volutions themselves, that is, the difficulty of recog- nizing the constant unity of form in the multiplicity of the individual variations. In this part of the study it is first of all the duty of anatomists to 4 PREFACE. place in the hands of practitioners materials which shall make it possible for them to find their way easily in the apparent chaos of convolutions. Only then will they be able to record correctly the obser- vations made on the cadaver. The anatomists are not entirely disinterested in performing this service for the practitioners, since they expect in return material from which the hoped- for science may some time arise. For this object it has long been my intention to give a summary description of the cerebral convolu- tions for the use of physicians, and I think that its fulfilment has not been made superfluous by the later excellent works on this subject. The following de- scription, which rests throughout on my own inves- tigations, is especially supported by the study of the development of the cerebral convolutions in the foetus, the result of which will be more completely reported in another place. The accompanying figures are to be regarded not so much as pictures, as maps by which one may be placed in a position to find his way more easily in this region. Alexander Eckee. Freibprg, March, 1869. CONTENTS. Introduction PAGE 7 THE FISSURES AND CONVOLUTIONS OF THE SURFACE OF THE BRAIN. Principal Fissures of the Hemispheres . . .15 Fissura Sylvii ........ 15 Sulcus centralis ........ 16 Fissura parieto-occipitalis ..... 20 Lobes of the Brain, their Fissures and Convolu- tions .........22 Frontal Lobe . . . . . . . . 22 Gyrus centralis anterior ...... 23 Gyrus frontalis superior and gyrus rectus . . 24 Gyrus frontalis medius ...... 26 Gyrus frontalis inferior . . . . . . 28 Sulcus frontalis superior ...... 29 Sulcus frontalis inferior . ... . . . 29 Sulcus prsecentralis ....... 29 Sulcus olfactorius . . . . . . . 31 Sulcus orbitalis . . . . . . . .31 Parietal Lobe ........ 34 Gyrus centralis posterior ...... 35 6 CONTENTS. Sulcus interparietalis Lobulus parietalis superior . Praecuneus .... Lobulus parietalis inferior . Lobulus supramarginalis . Gyrus angularis Occipital Lobe .... Sulcus occipitalis transversus Fissura calcarina Cuneus ..... Lobulus extremus Gyrus occipitalis primus Gyrus occipitalis secundus Gyrus occipitalis tertius Gyrus descendens Sulci occipitales longitudinales Temporal Lobe .... Sulcus temporalis superior . Sulcus temporalis medius . Sulcus temporalis inferior Sulcus occipito-temporalis inferior Gyrus temporalis superior Gyrus temporalis medius . Gyrus temporalis inferior Gyrus occipito-temporalis medialis Gyrus occipito-temporalis lateralis Mediax Surface of the Hemisphere Sulcus calloso-marginalis Gyrus fornicatus Gyrus Hippocampi Gyrus uncinatus Fissura Hippocampi Gyrus deutatus.... [sland (of Reil)..... Appendix..... THE CONVOLUTIONS OF THE BBAIX. INTRODUCTION. That the cortex of the cerebrum, the undoubted material substratum of our intellectual activity, is not a single organ which enters into action as a whole with every psychical function, but consists rather of a multitude of organs, each of which sub- serves definite intellectual processes, is a view which presents itself to us almost with the force of an axiom. The opposite hypothesis of a single organ for the multiplicity of the intellectual functions would mark a stand-point about equally advanced with the abandoned conception of a " Vital Force." If, however, as we think is undoubtedly true, definite portions of the cerebral cortex subserve definite in- tellectual processes, there is a possibility that we may some day attain a complete organology of the brain-surface, a science of the localization of the cere- 8 CONVOLUTIONS OF THE BEAIN. bral functions. Such a science—that is, a knowl- edge of the psychical organs of the brain in all their relations—is certainly one of the most important problems for the anatomy and physiology of the next century, the solution of which will work no small transformation in psychology. There are many causes why this problem is still almost com- pletely unsolved. We have undoubtedly been too much discouraged from following this path by the ill success of the first serious attempt at a localization of the mental pro- cesses. Though Gall in the beginning followed the right road—that of a careful study of the brain— yet he very soon departed from it, and, starting from the fact which, speaking in general terms, is perfectly correct, that the form of the skull depends on that of the brain, believed that he could replace the labo- rious and rare examinations of the dead brain by those of the living cranium. Bringing certain bunch- es or bumps of the cranium into connection with cer- tain mental dispositions, for which purpose he had already in his youth collected materials, he now, with his scholar Spurzheim, made a system of Phrenology in which but little was said about the brain, and which, in this form of a scientific structure, was thor- oughly defective. Hence, as may be supposed, the so-called science INTRODUCTION. 9 of Phrenology has remained since its beginning at the same point, and has fallen from the hands of earnest inquirers, especially the anatomists and physiologists, who turn away from it with de- served neglect, into those of an entirely different class. The travelling phrenologists who wander around with plaster heads of Schiller, Napoleon, and some celebrated rascals, and cipher out a character from a number of bumps on the skull, are well known. Few of them have ever seen a brain. It was not alone the reaction from this unsuccess- ful first attempt, which deterred from a continua- tion in the path marked out, possibly fruitful in re- sults; but the necessary conditions were wanting. In spite of the certain knowledge that the brain- surface is the organ of the soul, .and in spite of the consequent urgent summons to the anatomical study of the cerebral convolutions, this was until very lately much neglected, or rather the clew was wanting to guide one correctly in this labyrinth. The convolutions were considered as a bundle with- out system, and the artists drew them as they might draw any dishful of macaroni. It was at first gradu- ally seen that certain furrows and convolutions are more constant than others; but, so long as attention was confined to the fully-developed human brain, actual progress was not possible. Comparative anat- 10 CONVOLUTIONS OF THE BRAIN. omy and the history of development, these lamps of human anatomy, first brought light into this dark- ness. It was the works of Huschke, and especially of Gratiolet, on the monkey-brain, which proved the harmony in the structural plan of the cerebral con- volutions of the apes and those of man, and thus for the first time prepared the way for the understand- ing of the latter. Yet, any thing is fully understood only through itself, and every completed growth through its own growing; and thus tracing the de- velopment of the human convolutions is certainly the way by which alone a correct insight can be gained. This way has already been followed by various inquirers, as Gratiolet, Reichert, and Bi- schoff, and the following demonstration of the con- volutions is throughout founded on the study of their development in the foetus. This is also the only way to learn the law of formation of the convo- lutions, that is, the formation of the convolutions as a necessary consequence of certain mechanical pro- cesses of the growth of the brain and skull. Up to the present time we are far removed from such a knowledge. At the farthest, the formation of the fossa Sylvii is open to an explanation in this point of view. The relations between the arrange- ment of the arterial vessels of the brain and that of the convolution, to which Reichert has called atten- INTRODUCTION. 11 tion, are certainly not without meaning. What Bi- schoff * says is also perfectly correct, that a large num- ber of the convolutions of the cerebral hemispheres are arranged around the ends of the primary fur- rows in more or less simple or complicated arches; and it cannot be otherwise, for the ranges of moun- tains enclosing a valley must necessarily pass into each other where the valley ends, but no special explanation seems to be thereby disclosed. If we consider the arrangement of the convolu- tions in general, there may be distinguished first, chief or primary convolutions; then secondary or subordi- nate convolutions ; and, finally, tertiary convolutions. The chief or primary convolutions or folds are like great mountain-chains whose direction, as it has been correctly expressed, lends to a region its charac- teristic features. The secondary folds originate by the splitting of a primary convolution into smallei ones by the formation of longitudinal furrows, as secondary mountain-ranges arise from the formation of longitudinal valleys. The deep furrows which separate the chief con- volutions from each other, we may name chief fur- rows ; those which separate the secondary convolu- tions from each other, secondary furrows ; and, finally, the tertiary convolutions are those little 1L. c, S. 34. 12 CONVOLUTIONS OF THE BRAIN. ranges jutting out into the chief furrows from the valley-sides of the chief convolutions, which, usually engaged between those of the opposite side, give to the bottom of the valley, or of the furrow, a zigzag course. These are usually plainly seen only when the borders of the chief furrows are pulled apart; in brains whose chief convolutions have grown smaller, from senile or other atrophy, with much infiltration of the pia mater, they come immediately to light. While the features of the chief convolutions are always arranged with considerable uniformity, numer- ous variations exist in the extent of the secondary and tertiary convolutions: in the first place, for the reason that sometimes few, sometimes many sec- ondary furrows are formed, and also because in one case hidden tertiary convolutions come to the sur- face ; in another, convolutions which usually are superficial sink deeper. In the first case, furrows are bridged over; in the latter, they exist where there are usually none. THE FISSURES AND CONVOLUTIONS OF THE CEREBRAL SURFACE. Each hemisphere of the cerebrum, as is well known, may be incompletely divided, by more or less deep indentations, into several divisions or lobes, which were first more accurately distinguished by Burdach1 as anterior lobe, lobus anterior, upper lobe, lohus superior, with the cover (operculum^), lower lobe, lobus inferior, and trunk-lobe, lobus can- dicis. Arnold has proposed, instead of these names, others derived from the principal surrounding bones, and these latter designations are those now common- ly used. Thus, we now distinguish the frontal lobe, lobus frontalis, parietal lobe, lobus parietalis, tem- poral lobe, lobus temporalis (also called sphenoidal lobe, lobus sphenoidalis, or temporo-sphenoidal. lobus 1 L. c, Bd. II., S. 169, et seq. 14 CONVOLUTIONS OF THE BRAIN. temporo-sphenoidalis), and occipital lobe, lobus occipi- talis. The trunk-lobe of Burdach, not standing in im- mediate relation with the skull, is distinguished either by this name, or as the island (of Reil), inter- mediate or concealed lobe, lobus intermedins, s. oper- tus (Arnold), or as central lobe, lobus centralis (Gra- tiolet). The demarcation of the single lobes from each other is only clear on certain surfaces; on the others they pass into each other without distinct boundaries. I shall, in the following pages, first consider the chief fissures by which the single lobes are separated from each other, then the single lobes in order, and in these again the fissures to be recog- nized upon them, and the lobules and convolutions bounded and formed thereby. The fissures are always the most important part, and are hence the point whence the description takes its departure. This shows most clearly the devel- opment of the cerebral surface in the foetus. Here three primary fissures, first of all, divide it off into a number of districts. Actual convolutions are formed in these districts only with the further prog- ress of the formation of fissures. The most import- ant separating fissures are the following: PRIMARY FISSURES. 15 I. PRIMARY FISSURES. 1. Fissuea s. Fossa Sylvii (#). This important cleft, by which one of the princi- pal divisions of the hemispheres is brought about, is not to be placed in the same category with the re- maining fissures of the cerebral surface. The latter originate simply from depressions or folds of the cerebral cortex at a comparatively late period of foe- tal life—the former appears as early as the third month, and in an entirely different way; that is, by the whole hemisphere curving itself in an arch, con- cave below, around the place of entrance of the cere- bral peduncle.1 The fissura Sylvii begins at the base of the brain behind the origin of the olfactory nerves, later- ally from the chiasma nervorum opticorum, in the 1 By this curve a shallow open trench, the fossa Sylvii, is formed on the lower surface of each hemisphere, which is thereby divided into an anterior and posterior portion. Since this trench runs from the lower surface to the lateral, first upward and then upward and backward, it separates the frontal and parietal from the temporal lobe. Later (in the sixth month) the oval trench is changed by the formation of the anterior upright branch into a triangular one; and, since now the lobes, frontal, parietal, and temporal, with their opposite borders, the first with its posterior, the second with its inferior, and the third with its superior, pressing toward a common centre, grow to meet each other, the bottom of the trench, formed by the " island," is gradually covered, and the originally wide-open pit, the fossa Sylvii, is changed into a nar- row cleft, the fissura Sylvii. 16 CONVOLUTIONS OF THE BRAIN. anterior perforated space, runs thence outward, grad- ually narrowing, and thus arrives at the arched lat- eral surface of the hemisphere. Here it immediately divides into two branches — an anterior shorter, steeply ascending, which is directed forward toward the frontal lobe, Ramus ascendens s. anterior (S"), and a posterior much longer, Hamus posterior s. hori- zontalis ($"), Fig. 1, which is directed- toward the posterior portion of the parietal lobe. The upper ends of both branches are sometimes simple, some- times radiating into several secondary fissures, and are surrounded by arched convolutions. Between these two branches hangs down the " cover," operculum, which is formed especially by the lower ends of the two central convolutions as they pass into each other, and by a small portion of the lower frontal convolution, and lower parietal lobule. It covers the " island " from above. It fits into the angle of the Y which is formed by the di- vergence of the two branches of the fossa Sylvii. 2. Sulcus Centralis. Central furrow. Husch- ke (c). Scissure de Rolando. Letjeet. Fissura transversa anterior. Pansoh. Postero parietal sulcus. Huxley. This fissure, which, though earlier mentioned, was first accurately described by Rolando, is, without ex- SULCUS CENTRALIS. Fig. 1. View of the Brain from the Side. F Frontal lobe ; P parietal lobe ; 0 occipital lobe ; T temporal lobe. S Fissura Sylvii; S' horizontal, S" ascending branch. c Sulcus centralis ; A anterior, B posterior central convolution. Pi Upper, Pj middle, Ps lower (or third) frontal convolution. f\ Upper, /a lower, fa vertical frontal fissure (sulcus praecentralis). Pi Upper, P3 lower parietal lobule; Pa gyrus supramarginalis, Pa' gyrus angularis. ip Sulcus interparietalis. cm End of the sulcus calloso-marginalis. Ox First, 03 second, 03 third, occipital convolution. po Fissura parieto-occipitalis. o Sulcus occipitalis transversus. oa Sulcus occipitalis longitudinalis inferior. Tx First, Pa second, T3 third temporal convolution. ti First,