HUXLEY ON THE RELATIONS OF MAN TO THE LOWER ANIMALS. 71 



Association, to find myself compelled to give a diametrical contradiction 

 to certain assertions respecting the differences which obtain between the 

 brains of the higher apes and of man, which fell from Professor Owen ; 

 and in the interest of science, it is well that the real or apparent opposi- 

 tion of competent inquirers, as to matters of fact, should be put an end 

 to as soon as possible, by the refutation of one or the other. Happily, it 

 is unnecessary that I should trust to my memory of what took place on 

 the occasion to which I refer; for the assertions alluded to were already 

 familiar to me, inasmuch as their substance occurs in two of Professor 

 Owen's latest works — the paper " On the Characters, Principles of Divi- 

 sion, and Primary Groups of the Class Mammalia," read before the 

 Linnsean Society on February 17th, and April 21st, 1857; and the essay 

 " On the Classification of the Mammalia," delivered as a lecture before 

 the University of Cambridge. 



I quote from the former essay, as that intended for an audience of 

 experts, and hence, in all probability, to be regarded as more strictly 

 scientific : — 



" In man, the brain presents an ascensive step in development, higher and more 

 strongly marked than that by which the preceding sub-class was distinguished from the 

 one below it. Not only do the cerebral hemispheres (figs. 5 & 6 A) overlap the olfactory 

 lobes and cerebellum, but they extend in advance of the one, and further back than the 

 other (fig. 6, C). Their posterior development is so marked, that anatomists have 

 assigned to that part the character of a third lobe; it is peculiar to the genus Homo, and 

 equally peculiar is the posterior horn of the lateral ventricle, and the l hippocampus minor,' 

 which characterise the hind lobe of each hemisphere. 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 re- 

 gard 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 (fig. 6)." 



It might be a grave question whether, granting the existence of the 

 differences assumed to distinguish the human brain, they would justify 

 the establishment of a sub-class for the genus Homo ; but that difficulty 

 is not worth discussing, inasmuch as I shall endeavour to demonstrate, 

 in the course of the following pages, the accuracy of the three counter 

 statements which I made to the audience assembled in Section D, 

 viz. : — 



1. That the third lobe is neither peculiar to, nor characteristic of 

 man, seeing that it exists in all the higher Quadrumana. 



2. That the posterior cornu of the lateral ventricle is neither pecu- 

 liar to, nor characteristic of man, inasmuch as it also exists in the higher 

 Quadrumana. 



3. That the Hippocampus minor is neither peculiar to, nor character- 

 istic of man, as it is found in certain of the higher Quadrumana. 



T support the first two propositions by the evidence of every original 

 observer who has written upon the subject, including Professor Owen 



* Here occurs the note which I have already quoted at p. 69. The italics in the 

 above extract are my own. 



