THE EXTERNAL FORM OF ANTHROPOID APES. ^1 



the helix and anti-helix are developed, in others 

 they are wanting. The tragus and anti-tragus are 

 more or less apjDarent 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. 5. — Ear of chimpanzee. 



arms, reaching to the knees, and a long hand, which 

 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, 



