262 ON THE RELATIONS OF MAN 



No doubt, this is a very striking difference, but it loses 

 much of its apparent systematic value, when viewed by 

 the light of certain other equally indubitable facts respect- 

 ing cranial capacities. 



The first of these is, that the difference in the volume 

 of the cranial cavity of different races of mankind is far 

 greater, absolutely, than that between the lowest Man and 

 the highest Ape, while, relatively, it is about the same. For 

 the largest human skull measured by Morton contained 

 114 cubic inches, that is to say, had very nearly double 

 the capacity of the smallest ; while its absolute prepon- 

 derance, of 52 cubic inches is far greater than that by 

 which the lowest adult male human cranium surpasses 

 the largest of the Gorillas (62 34$=27). Secondly, 

 the adult crania of Gorillas which have as yet been measured 

 differ among themselves by nearly one-third, the maximum 

 capacity being 34.5 cubic inches, the minimum 24 cubic 

 inches ; and, thirdly, after making all due allowance for 

 difference of size, the cranial capacities of some of the 

 lower Apes fall nearly as much, relatively, below those 

 of the higher Apes as the latter fall below Man. 



Thus, even in the important matter of cranial capacity, 



cubic inches. The minimum capacity which I have assumed above, 

 however, is based upon the valuable tables published by Professor 

 R. Wagner in his " Vorstudien zu einer wissenschaftlichen Morpho- 

 logic und Physiologic des menschlichen Gehirns." As the result of 

 the careful weighing of more than 900 human brains, Professor 

 Wagner states that one-half weighed between 1200 and 1400 

 grammes, and that about two-ninths, consisting for the most part 

 of male brains, exceed 1400 grammes. The lightest brain of an 

 adult male, with sound mental faculties, recorded by Wagner, 

 weighed 1020 grammes. As a gramme equals 15.4 grains, and a 

 cubic inch of water contains 252.4 grains, this is equivalent to 62 

 cubic inches of water ; so that as brain is heavier than water, we 

 are perfectly safe against erring on the side of diminution in taking 

 this as the smallest capacity of any adult male human brain. The 

 only adult male brain, weighing as little as 970 grammes, is that of 

 an idiot ; but the brain of an adult woman, against the soundness of 

 whose faculties nothing appears, weighed as little as 907 grammes 

 (55.3 cubic inches of water) ; and Reid gives an adult female brain 

 of still smaller capacity. The heaviest brain (1872 grammes, or 

 about 115 cubic inches) was, however, that of a woman ; next to 

 it comes the brain of Cuvier (1861 grammes), then Byron (1807 

 grammes), and then an insane person (1783 grammes). The lightest 

 adult brain recorded (720 grammes) was that of an idiotic female. 

 The brains of five children, four years old, weighed between 1275 

 and 992 grammes. So that it may be safely said, that an average 

 European child of four years old has a brain twice as large as that 

 of an adult Gorilla. 



