THE NEWT AND ITS ALLIES 255 



brown color, and eventually the olive-green or viridescent 

 color of the adult. It then takes to the water and is 

 found especially in springs, and in ponds and brooks fed 

 by springs. It now subsists on various aquatic worms, 

 crustaceans, insects, and mollusks. The newt gains oxygen 

 for respiration by swallowing air mixed with water. 1 



Distribution. The Amphibia live chiefly in tropical and 

 subtropical countries, although a number of them belong 

 to the colder parts of the temperate zone. There are no 

 strictly polar species, although one species of frog extends 

 from Massachusetts north to Alaska. The Gymnophiona 2 

 are confined to tropical countries and are most abundant 

 in South America. They live, like earthworms, in the 

 ground and have more or less rudimentary eyes. The 

 Urodela are confined in their distribution to the Northern 

 Hemisphere (excepting that two or three species extend 

 along the Andes south of the equator). North America 

 is especially rich, both in species and individuals, of Uro- 

 dela. The Anura, or toads and frogs, are found in all parts 

 of the world, especially in South America and Australia. 



Families of Urodela. Of the American Urodela, 3 the 

 Sirenidae include the Siren, 4 or mud-eel, of the Southern 

 States. This species becomes 60 centimetres long, and is 

 of a dark lead color (Fig. 239). It is needlessly feared 

 by the negro rice cultivators, who slaughter it in great 

 numbers. 



1 Newts may be captured by sweeping with a net the muddy bottoms 

 of small, spring-fed pools. They can be kept for months in an aquarium, 

 where they should be fed thrice a week with earthworms or freshly 

 chopped beef. 



2 From yv/mv6s, naked ; 60iW, a fabulous, snake-like animal. 



3 ou/sd, tail ; SiJXos, conspicuous. 4 A mythological creature. 



