must be admitted by any one who contrasts the figure 2, Plate I., of Sch. van der Kolk and Vrolik, not merely with the accompanying photograph, fig. 5, but even with Tiedemann's and Macartney's figures. Hence, the enormous surface of the cerebellum seen in the upper view of the encephalon, in the Dutch anatomists' representation. We shall examine hereafter the merits, or defects, of their representation of the interior of the lateral ventricle.
Lastly, M. Gratiolct's figures of the Chimpanzee's brain, which are at once the latest and most trustworthy, were taken from a specimen preserved in the Museum at Paris, the form being restored (restituées) by constant reference to that of the cranial cavity, from which it had been removed. The general shape of the entire brain, the relations of its several parts, the position of the cerebellum, the various convolutions and all their surface markings, are most conscientiously reproduced, and, so far as the external anatomy of the brain is concerned, leave little room for improvement. The multiplication of accurate data on such a subject is, however, most desirable, and in the face of the very different statements just now made, as to matters of fact, in the anatomy of the Simian brain, new materials for consideration cannot but be welcome to all parties. More particularly it has seemed to me that, on the one hand, our figures 2, 4, and 5, so clearly demonstrate the defects of Schroeder van der Kolk's and Vrolik's representations, and, on the other, all the figures establish, so satisfactorily, the accuracy of M. Gratiolet's restorations, that their publication will be useful to science. The view of the lateral ventricle is also as complete as could well be obtained. In no case has anything been altered or restored.[1]
In proceeding to describe the brain, from which these photographs have been taken, I must observe that I have studied it side by side with an average human brain, belonging to an adult, of whose cranial cavity I also took a plaster cast, to serve as a standard of correction in all questions of form, size and relative position. Wherever, in the course of the following description, any comparison is made between the human and Chimpanzee's encephalon, it must be understood to refer to this particular human brain.
The general form of the cerebrum of the Chimpanzee, when viewed from above, is not so much pyramidal, as Tiedemann indicates, but rather, as Gratiolet figures it, it is a short, wide, ovoid, having its larger end turned backwards, somewhat pointed behind, and considerably so in front. It contrasts markedly, with the long ovoidal shape of the human cerebrum, viewed on the same aspect. Placed side by side, the difference between them is seen to consist, chiefly, in the greater length and more equal width, in man, of the anterior portion,
- ↑ I am greatly indebted to my friend Mr. Herbert Watkins, for his pains and skill in securing photographs of the natural size of the parts, from which the accompanying figures are reductions. Complete sets of ten full-sized photographs will be supplied by him, or by the Publishers of this Journal.
