54 SECRETS OF ANIMAL LIFE 



frogs fall victim to the appetite of many enemies, 

 such as birds of prey, stoats, and grass-snakes, 

 so that only a fraction of the young migrants is 

 left to make the return -journey in late autumn. 

 They are then about three-quarters of an inch long. 

 As the grass-frog does not become mature for three 

 years, it is likely that some of the youngsters 

 winter in suitable quarters far afield. But Dr. 

 Hempelmann, the author of a fine recent (1908) 

 monograph on the frog, says of the species we have 

 been discussing that the adults usually seek out 

 the water again in autumn and spend about four 

 months of winter buried in the mud thereof. What- 

 ever be the exact truth about the winter-quarters, 

 the frog's year is eventful indeed. How many 

 years are granted it we do not know. 



