532 AMPHIBIA. 



be taken for the cry of a pack of hounds in full chase ;" and 

 in the stillness of night, "the din of their united voices may fre- 

 quently be heard at the distance of a league, especially on the 

 approach of rain." After the young are hatched by the heat of 

 the sun, as in the case of the Common Frog, they continue in 

 the tadpole state about two months, swimming in the water and 

 feeding upon insects and worms. When the tail and gills have 

 disappeared, they, with unerring instinct, take to the woods. 

 The Tree Frog lives about thirty-six years. It is slow in attain- 

 ing its full growth, which does not take place until the fourth 

 year; nor does it breed before this period. Its fine green color 

 is not perpetual ; after the breeding season, the animal becomes 

 of a reddish brown, which soon changes to gray, mottled with 

 reddish ; the color next assumed is blue, and this again changes 

 to green, which is the summer tint. The agreeable colors and 

 sprightliness of this frog, occasion it, not unfrequently, to be kept 

 in cages. 



The NORTHERN TREE FROG, H. versicoJor, (Lat. changing 

 color,) is spread over a large part of the United States. This 

 Frog is particularly clamorous in rainy weather. Dr. DeKay 

 says he has been assured "that it possesses ventriloquial powers 

 in no inconsiderable degree." It appears to assimilate its color 

 to that of the tree on which it rests. This species is very simi- 

 lar to H. viridis, of Europe, (see Chart.) 



THIRD FAMILY. Bufoida, (Lat. bufo, a toad.) TOADS. 



In the Toads, the tailless Batrachian structure has its highest 

 development. Cuvier distinguishes them as having an inflated 

 body, a warty or tuberculous skin, and a tumor of variable size 

 behind each eye, consisting of a gland from the pores of which 

 exude an unctuous and offensive fluid. They have no teeth; the 

 hind limbs do not much exceed in length the fore pair. They 

 crawl rather than leap, and after passing from the tadpole state, 

 retire from the neighborhood of water to dry situations. Their 

 saliva has been supposed to be poisonous; but this is a mistake. 

 There are, however, glands on the skin of the back and sides, 

 that give out a fluid which in some species is acrid, capable of 

 producing irritation in a very sensitive skin, and probably intend- 

 ed for the defence of the Toad against the attacks of carnivorous 

 animals. 



Toads are nocturnal in their habits, evening and night being 

 the principal season of their activity, and their favorite slugs then 

 also creeping abroad. They hibernate in holes in the ground, 



