Chap. 34 



AMPHIBIANS 



711 



Fig. 34.25. Photograph ot the body cavity and ovary of the frog, Rana pipiens, 

 at the height of ovulation. (Courtesy, Rugh: The Frog. Philadelphia, The Blakiston 

 Co., 1951.) 



The finger-shaped fat bodies, present in both sexes, provide extra food for 

 the gonads when the sex cells are growing. The secondary sex characters of 

 male frogs are stouter arm and pectoral muscles and swollen, roughened 

 nuptial pads on their "thumbs." 



Mating is preceded by springtime assemblies and congregational singing, 

 mostly by the males. The females come to these assemblies a little later than 

 the males and mating begins immediately. The male rests on the back of the 

 female with his forelegs around her body and mating pairs float with their 

 heads just above water. When the female finally expels the eggs, the male dis- 

 charges the seminal fluid over them. Fertilization occurs at once, and with 

 this process the first cell of a new individual comes into existence (Chap. 19). 



Frogs in Folklore 



Frogs have played a prominent part in folk tales and legends. They appear 

 on tribal crests and in designs wrought on dishes and clothing (Fig. 34.26). 



