THE INTERPRETER 1 25 



It must not be overlooked, however, that there is a 

 very striking difference in absolute mass and weight 

 between the lowest human brain and that of the 

 highest ape, a difference which is all the more re- 

 markable when we recollect that a full-grown Gorilla is 

 probably pretty nearly twice as heavy as a Bosjes man, 

 or as many a European woman. It may be doubted 

 whether a healthy human adult brain ever weighed 

 less than 31 or 32 ounces, or that the heaviest gorilla 

 brain has exceeded 20 ounces. This is a very note- 

 worthy circumstance, and doubtless will one day help 

 to furnish an explanation of the great gulf which in- 

 tervenes between the lowest man and the highest 

 ape in intellectual power; 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 

 relatively and absolutely, than that between the lowest 

 man and the highest ape. The latter, as has been 

 seen, is represented by, say, 12 ounces of cerebral 

 substance absolutely, or by 32 : 20 relatively; 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 family distinction resting chiefly 

 on his dentition, his pelvis, and his lower limbs. 



Thus, whatever system of organs be studied, the 

 comparison of their modifications in the ape series 

 leads to one and the same result — that the structural 

 differences which separate Man from the Gorilla and 

 the Chimpanzee are not so great as those which 

 separate the gorilla from the lower apes. 1 



1 16., p. 103. 



