67 



subject, and a retention of the character met with in the lower 

 quadmmanaj the scaphoid bone being divided in the orang-outang. 

 In the chimpanzee the bones of the carpus are eight, as in the 

 human subject, but differ somewhat in form. If the upper ex- 

 tremities are so extraordinary for their disproportionate length, the 

 lower ones are equally remarkable for their disproportionate small- 

 ness in comparison with the trunk, in the orang. The femur is 

 short and straight, and the neck of the thigh-bone comparatively 

 short. The head of the thigh-bone in this animal, which requires the 

 use of these lower prehensible organs to grasp the branches of trees, 

 and to move freely in many directions, is free from that ligament 

 which strengthens the hip-joint in man; the head of the femur in 

 the orang is quite smooth, without any indication of that attach- 

 ment. Here, again, the chimpanzee manifests a nearer approach 

 to man, for the liyamentum teres is present in it in accordance 

 with the stronger and better development of the whole hind-limb. 

 This approximation, also, is more especially marked in the larger 

 development of the innermost of the five digits of the foot in the 

 chimpanzee, which is associated with a tendency to move more fre- 

 quently upon the ground, to maintain a more erect position than 

 the orang-outang, and to walk further without the assistance of a 

 stick. The foot, in both these species of anthropoid orangs, is 

 characterized by the backward position of the ankle-joint surface 

 presented by the astragalus to the tibia, which serves for the trans- 

 ference of the superincumbent weight upon the foot; by the 

 comparatively feeble development of the backward projecting pro- 

 cess of the calcaneum ; by the obliquity of the articular surface of 

 the astragalus, which tends to incline the foot a little inwards, 

 taking away from the plantigrade character of the creatures and 

 from their capacity to support themselves in an erect position, and 

 giving them an equivalent power of applying their prehensile 

 feet to the branches of the trees in which they live. 



In both the orang and chimpanzee the skull is articulated to 

 the spine by condyles, which are placed far back 011 its under surface. 

 The cranium is small, characterised by well-developed occipital and 

 sagittal ridges; the occipital ridges in reference to the muscles sus- 

 taining the head ; and the sagittal ones in reference to an increased 

 extent of the temporal muscles. The zygomatic arches are strong, 

 and well arched outwards. The lower jaw is of great depth, and 

 has powerful ascending rami, but the chin is wanting. The facial 

 angle is about 50 to 55 in the full-grown Simla satyrus, and 



F2 



