142 MAN AND THE LOWER ANIMALS n 



and of a Chimpanzee of the same length, in order to show the 

 relative proportions of the parts : the former taken from a 

 specimen, which Mr. Flower, Conservator of the Museum of 

 the Royal College of Surgeons, was good enough to dissect 

 for me ; the latter, from the photograph of a similarly 

 dissected Chimpanzee's brain, given in Mr. Marshall's paper 

 above referred to. a, posterior lobe ; b, lateral ventricle ; c, 

 posterior cornu ; x, the hippocampus minor. 



lowest man and the highest ape in intellectual 

 power j 1 but it has little systematic value, for the 

 simple reason that, as may be concluded from what 

 has been already said respecting cranial capacity, 

 the difference in weight of brain between the 

 highest and the lowest men is far greater, both 



1 I say help to furnish : for I by no means believe that it 

 was any original difference of cerebral quality, or quantity, 

 which caused that divergence between the human and the 

 pithecoid stirpes, which has ended in the present enormous gulf 

 between them. It is no doubt perfectly true, in a certain sense, 

 that all difference of function is a result of difference of struc- 

 ture ; or, in other words, of difference in the combination of 

 the primary molecular forces of living substance ; and, starting 

 from this undeniable axiom, objectors occasionally, and with 

 much seeming plausibility, argue that the vast intellectual 

 chasm between the Ape and Man implies a corresponding 

 structural chasm in the organs of the intellectual functions ; so 

 that, it is said, the non-discovery of such vast differences 

 proves, not that they are absent, but that Science is incompetent 

 to detect them. A very little consideration, however, will, I 

 think, show the fallacy of this reasoning. Its validity hangs 

 upon the assumption, that intellectual power depends altogether 

 on the brain whereas the brain is only one condition out of 

 many on which intellectual manifestations depend ; the others 

 being, chiefly, the organs of the senses and the motor appa- 

 ratuses, especially those which are concerned in prehension and 

 in the production of articulate speech. 



A man born dumb, notwithstanding his great cerebral mass 

 and his inheritance of strong intellectual instincts, would be 

 capable of few higher intellectual manifestations than an 



