THE EXTERNAL FORM OF ANTHROPOID APES. 39 



Fig. 8.— Ear of the 

 orang-utan. 



The small ear averages 55 mm. in length, and 

 12 mm. in width, and has a general resemblance in 

 structure to the human ear (Fig. 8). On the fore- 

 part of the short, thick neck there are irrecular. 

 and in some places very deep 

 circular folds of skin. The 

 throat- pouch distends part of 

 this slack, wrinkled skin, which 

 hangs down in front like a great 

 empty wallet (see Figs. 7 and 9). 

 The structure of the other 

 parts of the body lacks even to 

 some extent the powerful and 

 symmetrical formation which we 

 observe in the gorilla, and in- 

 deed in the chimpanzee. The trunk, with broad yet 

 rather angular and sloping shoulders, with flattened 

 breast, rounded back, and still more rounded belly, 

 is tun-shaped, and gives the impression of a want 

 of proportion. In lean individuals the gluteal 

 region resembles the projecting rump of a fowl, 

 and this may also be observed in the 3'oung gorilla 

 and chimpanzee. Tiie lonir, muscular arms reach 

 to the ankles when the animal is in an erect posi- 

 tion, and are altogether out of proportion with the 

 rest of the body. The powerful upper arm is 

 shorter than the lean forearm. The hand is long 

 and narrow. The thumb, which reaches as far as 

 the metacarpo-phalaugeal joint, has a displeasing 

 and almost rudimentary effect. A web unites the 

 fingers, sometimes extending along a third of the 

 first phalanx, sometimes along half. The middle 



