156 ANTHROPOID APES. 



only slightly developed. The muscles attached to the 

 cartilages of the ear are extremely scanty or partially 

 wanting, which is also sometimes the case with man. 

 The muscles of the helix are most strongly marked 

 in the gorilla (see, for example, Fig. 50, 21). Tiede- 

 mann, BischofTs brother-in-law, carefully observed 

 two living chimpanzees in Philadelphia for six 

 months without detecting any movement of the 

 ears. My own observation confirms his assertion 

 and the remarks of Darwin, which I have already 

 quoted, to the effect that anthropoids are incapable 

 of moving their ears. I know of no individual 

 exceptions. This is the more remarkable since 

 some men have retained the power of voluntarily 

 moving their ears, and the same power is also found 

 in some species of apes, such as the sea-cats, baboons, 

 macacas, and magots. 



It will not here be out of place to say something 

 of the characteristics, previously mentioned, of the 

 physiognomical expression of anthropoid apes. Thus, 

 for example, when the gorilla is agitated, he can 

 move the skin of his head and bristle the hair which 

 covers this region. The chimpanzee can also move 

 the skin of the head, but with no very apparent 

 bristling of the hair. The large male orang, which 

 was in the Berlin Aquarium in 1876, bristled his 

 hair and the skin of his head when he was much 

 enraged. It is known that in some instances man 

 also possesses this power. 



I have already spoken of the expression of the 

 eyes of these animals. I will only add that when 

 anthropoids of every species are in great pain or 



