"what are the fewest and simplest assumptions, which being granted, the whole existing order of nature would result,"[1] so the aim of the philosophic naturalist should be to determine how small a number of primitive types may be reasonably supposed to have given origin, by the ordinary course of "descent with modification," to the vast multitude of diversified forms that have peopled the globe in the long succession of geological ages, and constitute its present Fauna and Flora.
XX.—On the Affinities of the Brain of the Orang Utang. By George Rolleston, M. D., F. L. S., Linacre Professor of Anatomy.
As an opportunity has quite lately been afforded me of dissecting an Orang Utang, and as the University Museum possesses a considerable number of preparations which illustrate "the Zoological Relations of Man with the Lower Animals," it is less presumptuous in me than it otherwise would have been, to write upon a subject which has met with such able, as well as such recent, handling in the pages of this Journal. The great attention which the Paper to which I allude has attracted, renders it unnecessary for me either to recapitulate the views it propounds, or to specify in detail the points in which I agree, or those in which I feel myself compelled to differ, with the writer of it, whose authority I should be little likely needlessly to dispute.
In this Paper it will be with Human rather than with Simious Brains that I shall contrast and compare the Brain of the Orang Utang; incidentally, however, I shall institute comparisons between the Brain of the Asiatic Ape, and that of the smaller of the two most anthropoid African Apes, the Chimpanzee.
Tiedemann and Buffon exemplify, respectively, the two most opposite views which it is possible to entertain as to the questions of the actual anatomical truth, on the one hand, and of the possible anthropological bearings of the former of these two comparisons, on the other. Buffon, writing in 1766, speaks of the Brain of the Orang in much the same language as Tyson, in his "Anatomy of a Pygmie," had more than sixty years previously, applied to the Brain of the Chimpanzee. Between these Brains and that of Man there was, according to these writers, actually no difference at all—"Le Cerveau[2] est absolument de la même forme et de la même proportion." And the doctrine of the immateriality of the soul was, in the estimation of these authors, not merely compatible with, but a corollary of, these not wholly correct anatomical premises. Though the Brain in each is the same—in the one the power of thought exists, in the other it is absent. Thought,
