172 ECOLOGY AND LIFE HISTORY OF THE COMMON FROG 



exactly as a male. Voiceless before, she now grunts vigorously, with 

 a note that is perceptibly but not greatly different from the male 

 grunt. The combination of this warning note and the lack of stoutness 

 that caused the male to retain her until she had laid her eggs results in 

 a fairly rapid release. There is now no vigour in the grip of the males, 

 but spent females may often be retained for several minutes. It 

 seems improbable that a spent female would have much difficulty in 



Fig. 46. These Drawings Show the Difference between the Build 

 of a Male, on the Left, and the Spent Female on the Right 



The male, a more powerfully built animal, is actually stouter than the 

 slightly built female, so that the difference in figure cannot explain the 

 frequent seizure of spent females by males. The male was standing in water, 

 against the glass of the tank. The female was resting on the glass bottom, 

 and is seen as in the lower mirror. 



making her way through a crowd of males, but she would often be 

 detained for short periods. 



From my observations on this species, and also on Bufo bufo, and 

 Bombina variegata, I concluded that in each case the female can get rid 

 of the male any time she wants to, merely by using a dismissal stimulus, 

 different in each species. In B. bufo, it seems that it has a somewhat 

 negative character. If, when the complicated series of movements that 

 usually precedes the emission of eggs is complete, and the male has 



