n APES: HAND AND FOOT 129 



to a mere rudiment covered by the skin in the 

 Spider Monkey; and is directed forwards and 

 armed with a curved claw like the other digits, in 

 the Marmosets so that, in all these cases, there 

 can be no doubt but that the hand is more differ- 

 ent from that of the Gorilla than the Gorilla's 

 hand is from Man's. 



And as to the foot, the great toe of the Marmo- 

 set is still more insignificant in proportion than 

 that of the Orang while in the Lemurs it is very 

 large, and as completely thumb-like and opposable 

 as in the Gorilla but in these animals the second 

 toe is often irregularly modified, and in some 

 species the two principal bones of the tarsus, the 

 astragalus and the os calcis, are so immensely 

 elongated as to render the foot, so far, totally un- 

 like that of any other mammal. 



So with regard to the muscles. The short 

 flexor of the toes of the Gorilla differs from that 

 of Man by the circumstance that one slip of the 

 muscle is attached, not to the heel bone, but to 

 the tendons of the long flexors. The lower Apes 

 depart from the Gorilla by an exaggeration of the 

 same character, two, three, or more, slips becoming 

 fixed to the long flexor tendons or by a multipli- 

 cation of the slips. Again, the Gorilla differs 

 slightly from Man in the mode of interlacing of the 

 long flexor tendons : and the lower apes differ from 

 the Gorilla in exhibiting yet other, sometimes 

 very complex, arrangements of the same parts, and 

 173 



