370 



BATRACHIAN AMPHIBIA. 



are cleared, they are often thrown out in great numbers. Being re- 

 garded as venomous by the skives, they are instantly killed, or dread- 

 fully mangled. Sometimes they leave the soft mud, in which they 

 usually bmTOw, and take to the water, where they swim with great 

 quickness. They are occasionally taken by persons angling with a 

 bait of Earthworms. Sometimes, like Eels, they leave the water 

 and are found on dry land. A specimen, which was kept alive in 

 the Zoological Gardens in the Regent's Park, devom-ed about a dozen 

 and a half of Earthworms daily. 



Batrachian Amphibia. 



The name Batrachian (from the Greek /Sar^axo^j 

 a frog) is given to those Amphibians that resemble a 

 frog in their structure and general habits. All the 

 Batrachiahs, when young, undergo a series of trans- 

 formations or metamorphoses, so that they enter life 

 under an entirely difterent form from that which 

 they afterwards assume. In their first condition 

 they are usually designated Tadpoles. 



When the yoimg tadpole first leaves the egg it resembles 

 a little fish, and can live only in water. Its head is very 

 large, its belly protuberant, and its body quite destitute of 



Fig. 301.— tadpoles. 



limbs ; it is provided with a compressed tail, which sub- 

 sequently becomes elongated and much expanded. Its 

 mouth is a small, scarcely perceptible hole, and its bran- 

 chite consist only of a tubercle placed on each side of the 

 hinder part of the head. These appendages, however, 

 very soon lengthen and become divided into shreds 

 (Fig. 301a). The eyes grow perceptible through the skin, 

 and a small transverse slit appears under the neck, form- 



