50 



INTRODUCTION. 



to five or six, as in Bombinator pachypus (Fig. 21, a). 

 Bomblnator igneus and Hyla are intermediate between 

 the two extremes. Owing to the filling up of the 

 abdominal cavity by the more voluminous genital 

 organs, the lungs are usually smaller in females 

 than in males. In the genus Ban a (Fig. 21, c) 



Fig. 21. 



4 mmmm 



3 & MH'. [ ! ' 





13 





Bombinator pachypus. B. Pelobates fuscus. 

 c. Rana temporaria. 



the lungs, when fully distended, measure two- 

 thirds or more the length of the abdominal cavity 

 in males, one-third to one-half in females. In 

 Bombinator, Bufo, and Hyla they measure nearly 

 three-fourths that length in males, two-thirds in 

 females. In Pelobates they are equally developed in 

 both sexes, and larger than in any other genus, with 

 a seemingly superadded narrower terminal portion 

 bent inwards and forwards, tapering to a fine point 

 (Fig. 21, b) ; the length of the inflated lung consider- 



