206 GORILLAS AND CHIMPANZEES 



knuckles becomes wrinkled, and the web almost dis- 

 appears. This effect is more readily noticed in the 

 living animal than in the dead. The texture of the 

 skin in the palms is coarsely granulated, and the 

 palmar lines are indistinct. The great toe sets at 

 an angle from the side of the foot, like a thumb, but 

 has more prehensile power than that of the hand ; 

 but the foot is much less flexible, and has less pre- 

 hensile power. 



At this point I desire to draw attention to one 

 important fact. The tendons of the foot, which 

 open and close the digits, are imbedded in the palm 

 in a deep layer of coarse, gristly matter, which 

 forms a pad, as it were, under the sole of the foot, 

 and prevents it from bending ; therefore it is not 

 possible for the gorilla to sleep on a perch. In this 

 respect he resembles man more than the chim- 

 panzee does, but it is quite certain that neither of 

 them have the arboreal habit. The gorilla is an 

 expert climber, but cannot sleep in a tree. In the 

 hand the tendons which close the fingers are the 

 same length as the line of the bones, and this per- 

 mits him to open the fingers to a straight line, 

 which the chimpanzee cannot do. 



One other important point I desire to mention. 

 The muscles in the leg of a gorilla will not permit 

 it to stand or walk erect. The large muscle at the 

 back of the leg is shorter than the line of the bones 

 of the leg above and below the knee ; and when 

 this muscle is brought to a tension, those bones 

 form an angle of about 1 30 degrees, or thereabouts ; 



