28 



PHYSIOLOGY OF THE DOMESTIC ANIMALS. 



Fig. 20.— Non-Stkiated Muscular Fibkes, Isolated. (Klein.) 



The crosa-markings-indicate corrugations of the elastic sheath of the individual fibres. 



^"^IT- MiT -' * 



Fig. 21.— Various Kinds of Epithelial Cells. (Klein.) 



A, columnar cells of intestine; B, polyhedral cells of the conjunctiva; C, ciliated conical cells of the 

 trachea: D, ciliated cell of frog's mouth; E, inverted conical cell of trachea; F, squamous cell of 

 the cavity of the mouth, seen from its broad surface ; G, squamous cell, seen edgeways. 



Fig. 22.— Various Kinds of Spermatozoa. (Klein.) 



A, spermatozoon of guinea-pig not yet matured ; B. the same seen sidewavs, the head being flattened 

 from side to side ; C, a spermatozoon of the horse ; D, a spermatozoon of the newt. 



