II WEIGHT OF THE BRAIN 143 



relatively and absolutely, than that between the 

 lowest man and the highest ape. The latter, as 

 has been seen, is represented by, say twelve, ounces 

 of cerebral substance absolutely, or by 32 : 20 re- 

 latively ; but as the largest recorded human brain 

 weighed between 65 and 66 ounces, the former 

 difference is represented by more than 33 ounces 

 absolutely, or by 65 : 32 relatively. Regarded 

 systematically, the cerebral differences of man and 

 apes, are not of more than generic value ; his 



Orang or a Chimpanzee, if he were confined to the society of 

 dumb associates. And yet there might not be the slightest 

 discernible difference between his brain and that of a highly 

 intelligent and cultivated person. The dumbness might be the 

 result of a defective structure of the mouth, or of the tongue, 

 or a mere defective innervation of these parts ; or it might 

 result from congenital deafness, caused by some minute delect 

 of the internal ear, which only a careful anatomist could 

 discover. 



The argument, that because there is an immense difference 

 between a Man's intelligence and an Ape's, therefore, there 

 must be an equally immense difference between their brains, 

 appears to me to be about as well based as the reasoning by 

 which one should endeavour to prove that, because there is a 

 "great gulf" between a watch that keeps accurate time and 

 another that will not go at all, there is therefore a great 

 structural hiatus between the two watches. A hair in the 

 balance-wheel, a little rust on a pinion, a l>end in a tooth of 

 the escapement, a something so slight that only the practised 

 eye of the watchmaker can discover it. may be the source of all 

 the difference. 



And believing, as I do, with Cuvier, that the possession of 

 articulate speech is the grand distinctive character of man 

 (whether it be absolutely peculiar to him or not), I find it very 

 easy to comprehend, that some equally inconspicuous structural 

 difference may have been the primary cause of the immeasurable 

 and practically infinite divergence of the Humr.ii frou the 

 Simian Stirps, 



