THE EXTERNAL FORM OF ANTHROPOID APES. 31 



the helix and anti-helix are developed, in others 

 they are wanting. The tragus and anti-tragus are 

 more or less apparent in different individuals, as 

 well as the other modifications of the external carti- 

 lage of the ear. 



An aged male chimpanzee has broad, rather 

 rounded shoulders, a powerful chest, long muscular 



Fig. 6. — Ear of chimpanzee. 



arms, reaching to the knees, and a long hand, whic;h 

 seems to be very slender in comparison with that 

 of the gorilla. The thumbs vary in length, for the 

 most part reaching as far as the metacarpal pha- 

 langes, but not in all cases. The middle finger 

 is longer than" the other three; the first and third 

 fingers are shorter by the length of the last phalanx, 



