358 THE STUDY OF ANIMAL LIFE CHAP. 



perhaps connected.' We plant the soles of our feet flat 

 011 the ground, our great toes are usually in a line with 

 the rest, and we have better heels than monkeys have, 

 but no emphasis can be laid on the old distinction which 

 separated two-handed men (Bimana) from the four-handed 

 monkeys (Quadrumana), nor on the fact that man is 

 peculiarly naked. We have a bigger forehead, a less 

 protrusive face, smaller cheek-bones and eyebrow ridges, 

 a true chin, and more uniform teeth than the anthropoid 

 apes. More important, however, is the fact that the 

 weight of the gorilla's brain bears to that of the smallest 

 brain of an adult man the ratio of 2 : 3, and to the largest 

 human brain the ratio of 1:3; in other words, a man 

 may have a brain three times as heavy as that of a gorilla. 

 The brain of a healthy human adult never weighs less 

 than 31 or 32 ounces ; the average human brain weighs 

 48 or 49 ounces ; the heaviest gorilla brain does not 

 exceed 20 ounces. The cranial capacity is never less 

 than 55 cubic inches in any normal human subject, while 

 in the orang and the chimpanzee it is but 26 and 27 J 

 cubic inches respectively." The cerebral cortex, the 

 seat of intelligence, is said (by G. H. Parker) to include 

 9,200,000,000 nerve-cells, but these cells by themselves 

 represent a little less than a cubic inch of material and 

 weigh only 13 grammes ! 



But differences which can be measured and weighed 

 give us little hint of the characteristically human powers 

 of building up ideas and of cherishing ideals. It is not 

 merely that man profits by his experience, as many 

 animals do, but that he makes some kind of theory of it. 

 It is not merely that he works for ends which are remote, 

 as do birds and beavers, but that he controls his life 

 according to conscious ideals of conduct. Man is solidary 

 with the rest of creation, but he is also apart, as is plain 

 when we think of his power of articulate speech, his 

 realisation of his history, his inherent social sympathies, 

 and his gentleness. 



The arguments by which Darwin and others have 

 sought to show that man arose from an ancestral type 

 common to him and to the higher apes are the same as 



