76 



INTRODTJCTION. 



tail is about equally long, and provided with an ex- 

 tremely delicate, wavy, vibratile, hyaline membrane 

 or crest. As in the newts, they are collected together 

 in bundles, although devoid of a spermatophore. 



Fig. 29. 



Spermatozoa of Batraohians. A. Bombinator pachypus. B. Pelo- 

 hates fuscus. c. Bufo vulgaris, d. Hyla arborea. E. Rana 

 esculenta. P. Bana temporaria. (After La Valette St. George 

 and Leydig.) 



In Bomhinator a crest is present along the side of 

 the spindle-shaped head, and the tail is moderately 

 long, filiform, and devoid of a crest. The crest may 

 be partially detached from the head, and has been 

 taken to belong to the tail. 



In Ah/tes and Bufo the head is staff-shaped, pointed 

 in front ; the tail is about twice as long, with a deli- 

 cate crest. 



In Pelobates the head is long and thin, with strong 

 spiral windings, corkscrew-shaped, passing gradually 

 into the extremely long, delicate, filiform tail. 



The spermatozoa of Peloclytes bear much resem- 

 blance to the preceding, but the head is less twisted ; 

 the tail is also extremely long and filiform. 



