AN INTRODUCTION TO THE METAZOA 



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Fig. 46. — Various kinds of cells. A, female germ cell, ovum of a cat. B, 

 male germ cell, spermatozoon of a snake, Coluber. C, ciliated epithelium from 

 the digestive tract of a mollusk, Cyclas. D, cartilage of a squid. E, striated 

 muscle fiber from an insect larva, Corydalis cornulus. F, smooth muscle fibers 

 from the bladder of a calf. G, a nerve cell from the cerebellum of man. 

 (From Dahlgren and Kepner.) 



