ANTHROPOIDEA. 729 



the " four-handed " monkeys (Quadrumana), nor on the fact 

 that men are pecuharly naked. But " the arms are shorter 

 than the legs, and, after birth, the latter grow faster than the 

 rest of the body." 



Compared with the anthropoid apes, man has a bigger 

 forehead, a less protrusive face, smaller cheek bones and 

 supra-orbital ridges, a true chin, and more uniform teeth 

 (2, I, 2, 3), forming an uninterrupted horse-shoe-shaped 

 series without conspicuous canines. 



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 i : 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 Chimpanzee, 

 it is but 26 and 27-i cubic inches respectively." 



But, as Owen allowed long since, there is an " all-pervad- 

 ing similitude of structure " between man and the anthropoid 

 apes. As far as structure is concerned, there is much less 

 difference between man and the gorilla than there is between 

 the gorilla and the marmoset. 



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 those used to 

 substantiate the general doctrine of descent. The " Descent 

 of Man" is the expansion of a chapter in the ^^ Origin 

 of Species." The arguments may be briefly summarised. 



(i) Physiological. The bodily life of man is like that of 

 monkeys ; men and monkeys are subject to similar diseases ; 

 various human traits of gesture, expression, &c., are paralleled 

 among the "brutes;" reversions and monsters corroborate 

 the alliance sadly enough. 



(2) Morphological. The structure of man is like that of 

 the anthropoid apes; none of his distinctions, except that 

 of a heavy brain, are momentous ; there are about eighty 

 vestigial structures in his muscular, skeletal, and other 

 systems. 



