Page:Geological Evidences of the Antiquity of Man.djvu/501

Rh grey matter of the cerebrum, through the number and depth of its convolutions, attains its maximum of extent in Man.

'Peculiar mental powers are associated with this highest form of brain, and their consequences wonderfully illustrate the value of the cerebral character; according to my estimate of which, I am led to regard the genus Homo as not merely a representative of a distinct order, but of a distinct sub-class of the mammalia, for which I propose the name of "Archencephala."' The above definition is accompanied in the same memoir by the following note:—'Not being able to appreciate, or conceive, of the distinction between the psychical phenomena of a chimpanzee and of a Boschisman, or of an Aztec with arrested brain-growth, as being of a nature so essential as to preclude a comparison between them, or as being other than a difference of degree, I cannot shut my eyes to the significance of that all-pervading similitude of structure—every tooth, every bone, strictly homologous—which makes the determination of the difference between Homo and Pithecus the anatomist's difficulty; and therefore, with every respect for the author of the "Records of Creation," I follow Linnæus and Cuvier in regarding mankind as a legitimate subject of zoological comparison and classification.'

To illustrate the difference between the human and Simian brain, Professor Owen gave figures of the negro's brain as represented by Tiedemann, an original one of a South American monkey, Midas rufimanus, and one of the chimpanzee, fig. 54, p. 482, from a memoir published in 1849 by MM. Schroeder van der Kolk and M. Vrolik.