28 



PHYSIOLOGY OF THE DOMESTIC ANIMALS. 



FIG. 20. NON-STRIATED MUSCULAR FIBRES, ISOLATED. (Klein.) 



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



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 sideways, the head being flattened 

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



