Page:Natural History Review (1861).djvu/91

Rh However, the citation from the Memoir of Schroeder van der Kolk and Vrolik, given above, proves that in their opinion a rudimentary hippocampus minor does exist in the Chimpanzee, and Dr. Allen Thomson adds his valuable testimony in a still more decided manner to the same effect. In the letter which I have already quoted, he says:—

In another letter (the 11th of November, 1860), replying to further troublesome inquiries of mine, Dr. Thomson writes:—

Having now, as I trust, redeemed my pledge to prove that neither the third lobe of the cerebrum, nor the posterior cornu of the lateral ventricle, nor the hippocampus minor, are structures distinctive of and "peculiar to the genus Homo," I may leave it to the reader to decide the fate of the "sub-class Archencephala" founded upon the supposed existence of these three distinctive characters.

And here I might fairly leave the question; but, essential as I have felt it to be to my personal and scientific character to prove that my public assertions are entirely borne out by facts, I am far from desiring to deal with this important matter in a merely controversial spirit. Therefore, although the differences hitherto referred to are certainly nonexistent, I proceed to inquire whether there are any other marked and constant characters by which the human may be distinguished from the Simian brain.

Without doubt such characters are to be found; and in all probability, as in the case of any other two distinct genera, the more carefully and minutely our inquiries are carried out, the greater will be the number of these differentiæ. So far as my knowledge goes, the most prominent and important are the following:—

1 . In the anthropoid apes the brain is smaller, as compared with the nerves which proceed from it, than in man.