AN INTRODUCTION TO THE VERTEBRATES 243 



A CD 



FIG. 140. Various kinds of cells. 



A, female germ cell, ovum of a cat ; B, male germ cell, spermatozoon of a 

 snake ; C, ciliated epithelium ; D, cartilage ; E, striated muscle fiber ; F, 

 smooth muscle fibers ; G, a nerve cell from the cerebellum of man. (From 

 Dahlgren and Kepner.) 



