THE EXTERNAL FORM OF ANTHROPOID APES. 23 



dons, and skin. The several divisions of these padded 

 balls are separated from each other by furrows which 

 are longitudinal, oblique, and transverse, and more 

 or less distinct from each other. The black skin 

 which covers the sole of the foot is thick and horny, 

 but provided with a series of papillae. The whole 

 skin of an aged animal is of a deep black colour, 

 somewhat giossy, and covered with intersecting 

 wrinkles. 



Fig, 4, — The same animal at a still earlier age. 



The young male gorilla does not essentially differ 

 from the old male in its general and external ap- 

 pearance. Its skull is, however, without the crest 

 which characterizes the latter animal, and is still of 

 a rounded form in the region of the crown and occi- 

 put. At this age the head is not so high at the 

 back and on the top as in aged males. The orbits 

 are less prominent, the general aspect of the face is 



