202 REPTILES AND BATRACHIANS 



complete during the breeding season, in the presence of 

 a pair of internal vocal sacs, situated at the sides of the 

 throat, and by the presence of a pair of swollen pads on 

 the inner fingers, which, during the breeding season, are 

 covered with numerous black, horny spinules. 



The coloration varies enormously, no two specimens 

 being alike ; the ground colour, which may be grey, 

 brown, yellow, or red, is spotted or marbled with darker ; 

 the limbs are usually transversely banded. 



Although a terrestrial frog, spending most of its life in 

 fields and meadows, the Common Frog is not unfrequently 

 found in ponds throughout the summer, while many, 

 especially males, hibernate under water. The breeding 

 season falls in January and February in Central 

 Europe, usually in March in the North. The recurrence 

 of cold weather after the frogs have begun to spawn 

 may cause them to return to their winter quarters, 

 with the result that the breeding season may be 

 broken up into two or three periods within a couple of 

 months. The Common Frog exercises no discrimination 

 in the choice of the locality in which it lays its eggs, and 

 will spawn in large ponds, slow-running brooks, or even 

 in puddles, which are certain to dry up before the tadpoles 

 have completed their metamorphosis. 



The eggs, which vary in number from 1,500 to 4,000, 

 according to the size of the female, are perfectly round, 

 and form large clumps which float on the surface of the 

 water. The young are released two or three weeks after 

 the eggs have been laid, and are able to leave the water in 

 May or June, later in the extreme north or high up in the 

 mountains. In Scotland tadpoles are often still found in 

 August, and are even sometimes compelled to hibernate. 



