58 THE COMMON FROG. [chap. 



chians, in their adult condition, were also undoubtedly 

 animal feeders, but they may, in their young state, 

 have been vegetarians. At any rate the tadpoles of 

 the existing Urodela will eat vegetable matter, and 

 indeed probably sustain themselves mainly upon it. 



In cold latitudes the Batrachia, like the Reptilia, go 

 into the winter sleep called hibernation, as also do the 

 hedgehogs and bats amongst Mammals. 



The Frogs and Toads sometimes hide and shelter 

 themselves by creeping into out-of-the-way holes and 

 corners, but more generally they (as also the Newts) 

 bury themselves in mud at the bottom of ponds and 

 streams. In hot latitudes, some forms pass the dry 

 season in a similar state of lethargic inactivity. 



Many beasts, birds and fishes, range in flocks. 

 The Batrachians, however, usually wander about in a 

 solitary manner, and only congregate in the breeding 

 season. It is then that their vocal powers find utter- 

 ance, though only in the Anourous order ; the tailed 

 Batrachians never make more than a very feeble 

 sound. 



As regards the geographical distribution of the 

 whole class, the northern hemisphere, and especially 

 the American portion of it, is the more richly 

 furnished. Africa, India, and Australia are the most 

 poorly supplied on the whole, because, though pos- 

 sessing very many kinds of frogs and toads, the whole 

 Eft order is unknown in those regions. 



Our question "■ What is a Frog .'' " has now been 

 somewhat further answered ; but it cannot be com- 

 pletely so until the organization of the animal has been 

 more fully surveyed, and not only the relation of the 



