106 MAN AND THE LOWER ANIMALS. n 



guised by the mass of bone which is built up 

 against it (Fig. 17). 



But the roofs of the orbits rise more obliquely 

 into the cranial cavity, thus diminishing the space 

 for the lower part of the anterior lobes of the 

 brain, and the absolute capacity of the cranium 

 is far less than that of Man. So far as I am aware, 

 no human cranium belonging to an adult man 

 has yet been observed with a less cubical capacity 

 than 62 cubic inches, the smallest cranium ob- 

 served in any race of men by Morton, measuring 

 63 cubic inches; while, on the other hand, the most 

 capacious Gorilla skull yet measured has a content 

 of not more than 34| cubic inches. Let us assume, 

 for simplicity's sake, that the lowest Man's skull 

 has twice the capacity of that of the highest 

 Gorilla.* 



* It has been affirmed that Hindoo crania sometimes 

 contain as little as 27 ounces of water, which would give 

 a capacity of about 46 cubic inches. The minimum capac- 

 ity which I have assumed above, however, is based upon 

 the valuable tables published by Professor R. Wagner in 

 his Vorstudien zu eiuer wissenschaftlichen Morphologie 

 und Physiologie rfcs menschlichen Gehrins. 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, con- 

 sisting 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 gi-ains, 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 



