Xo. 635] THE HAIR OF MAMMALS 



503 



rangement of the pigment granules. There seems to be 

 also a wide variation in color value and color depth of the 

 pigment granules, a variation which is especially well 

 brought out by the use of reflected light, or of dark field 

 illumination. These methods of examination will be ex- 

 plained later. 



In a recent contribution to the structure of the mam- 

 malian hair 4 the author has pointed out that mammal 

 hairs may be conveniently classified, on the basis of the 

 configuration of the cuticular scales and medulla, as 



I. Imbricate 



1. Ovate, represented by Figs. 1 to 7 



2. Acuminate, represented by Figs. 8 to 20 



3. Elongate, represented by Figs. 21 to 35 



4. Crenate, represented by Figs. 36 to 67 



5. Flattened, represented by Figs. 68 to 92 



