OUR BEST FEATURES 



mammals indicate that its cartilage is a new local 

 development in the mammals. 



The outer ear in mammals takes on a great 

 diversity of forms, from the trumpet-like ear of 

 antelopes and other keen-eared, defenceless herbi- 

 vores to the huge and imposing ear-flaps of the 



Fig. 108. Human (A) and Macaque (B) Embryos, Showing Origin 



OF THE External Ear from Six Tubercles. (From Leche, 



A, after Selenka, B, after His, Keibel.) 



(From Der Mensch, Gustav Fischer.) 



African elephant. Some of the bats have large 



ears of extreme complexity, while the whales have 



only a thread-like tube beneath the skin that 



marks the last vestige of the external ears. Very 



little in detail is known either about the precise 



functioning of the different forms of external ear 



or about the origin and significance of its many 



subdivisions, such as the tragus, an ti tragus, crus 



of the helix and antihelix and the marginal fold or 



211 



