No. 635] 



THE HAIR OF MAMMALS 



eter of the hair shaft itself, in micra 3 which constitute 

 the series of determinative criteria for each species of 

 hair. 



Medullas can be conveniently grouped, according to 

 their forms, as they: (1) discontinuous, as in the hair of 

 the Botta's pocket gopher (Thomomomys bottce) (Fig. 

 3) ; (2) continuous, as in the hair of the kinkajou (Cer- 

 coleptes caudivolvulus) (Fig. 7) ; and (3) fragmented, as 

 in the hair of the wombat {Phascolomys ur sinus) (Fig. 

 64). 



The cuticular scales fall readily into two well-marked 

 types, the: (1) imbricate, represented in the hair of the 

 civet (Arctogalidia fusca) (Fig. 1) ; and (2) coronal, rep- 

 resented in the hair of the majority of the bats, e.g., the 

 mastiff bat (Molossus sinaloce) (Fig. 105). 



The cortex element of the hair shaft structure exhibits 

 few or no traces of the form of its component fusiform 



