POSTURE OF GORILLA 225 



In this respect he resembles man more than the chim- 

 panzee does, but it is quite certain that neither of them 

 has the true arboreal habit. The gorilla is an expert 

 climber, but he 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 permits 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 the gorilla will not permit the animal 

 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. When this muscle is brought 

 to a tension, those bones form an angle of from 130 to 

 160 , or thereabouts. So long as the sum of two sides 

 of a triangle is greater than the other side, a gorilla can 

 never bring his leg into a straight line. In the infant 

 state, while the muscles are elastic and the bones less 

 rigid, the leg can be forced nearly straight. The habit of 

 hanging by the arms and walking with them in a straight 

 line develops the corresponding muscle in those members 

 so that the bones can be brought in line and the limbs 

 straightened. 



The gorilla can stand upon his feet alone and walk a 

 few steps in that position ; but his motion is very awk- 

 ward ; his knees turn outward, forming an angle of 40 or 

 50 on either side of the mesial plane. He never attempts 

 to walk in this position except at perfect leisure, and then 

 he holds on to something with his hands. 



The leg of the gorilla from the knee to the ankle is 

 almost the same in size. In the human leg there is what 



