64 SALAMANDERS, TOADS, AND FEOGS. 



As for the fishes of salt-water, they go to unknown abysses and dis- 

 tances, returning when spring opens to ascend the rivers and revisit their 

 old haunts. It may be said of fishes generally, therefore, that they spend 

 their winters in deep and comparatively warm water, out of the reach of 

 the ice and cold which chains the brooks and shallow ponds. 



Next to be mentioned is the .class of half water, half land animals, 

 called Batrachia, after the Greek name of the frog. The batrachians 

 include those repulsive, lizard-shaped, flabby creatures, haunting western 

 and southern streams, which are called sirens, water-dogs, and mud-pup- 

 pies; the more graceful salamanders, newts, efts, and tritons; and, as 

 the highest division, the frogs, toads, and tree -peepers, the "tadpoles" 

 of which lose their tails and their lizard-like form when they become of 

 full age. 



Few of these animals live in deep, clear water; the great majority 

 haunt muddy streams and marshes, or else spend most of their time on 

 dry land. Their food is obtained either from the water or from insects, 

 and cold weather cuts off the supply in both cases. It is necessary, there- 

 fore, as with the snails, that they -should be able to survive the winter 

 without eating, and they do so in pretty much the same way as the snails, 

 by creeping into the mud at the bottom or on the margin of streams and 

 ponds, and going into a half-torpid 6leep. Some of the salamander-like 

 batrachians can live wholly in the water, being provided with gills like 

 fishes. These, therefore, can retain their activity where the water is deep 

 enough to protect the bottom from freezing, and, as they live mainly in 

 southern streams, they know little about cold weather ; otherwise they 

 seem to hide away among the roots of aquatic herbage. Toads must have 

 air to breathe, and hence could not exist underneath ice, except in a state 

 of torpor, where breathing is suspended ; but frogs are capable of skin- 

 respiration, and can live under water indefinitely if food is supplied. 



Their hibernation, whether in the mud, as in the case of frogs; in 

 holes in the earth, in cellars, or under old logs, as toads do; or in the 

 rotten wood inside hollow trees, which some of the tree-toads are sup- 

 posed to choose, is not so strict and lasting as it is with snails and insects. 

 It depends only on the degree of cold, so that it not unfreqnently happens 

 that the piping of frogs will be heard here and there in midwinter when 

 the snow has left the ground and the sun thaws out the frost. But a chill- 

 ing wind shuts their voices up again until early spring, when they are the 

 first to respond to the invitation of the new season. There is reason to 

 believe, however, that all the frog-like batrachians do not live over from 



