METAMORPHOSES OF BATRACHIA. 



577 



preserve, and in their early state they undergo some remarkable 

 metamorphoses. They at ^first resemble fishes in their external 

 form, as well as in their internal structure ; and it is by degrees 

 that they acquire the characters of their class. Whilst they are 



F!. 333. 



FIG. 336. 

 FIGS. 332 337. METAMORPHOSES OF BATEACHIA. 



in this transitory state, the name of tadpoles is given to them, 

 and the metamorphoses which they undergo are greater or less 

 according to the species. Frogs, Toads, and other species formed 

 almost on the same plan, are, of all the Batrachians, those whose 

 metamorphoses are the most complete. At the time when the 

 young tadpole of the Frog comes from the egg, it is very like a 

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

 abdomen protuberant, and its body, deprived of members, is 

 terminated by a long and compressed tail : its mouth is as yet 

 but a small aperture, hardly perceptible ; and its gills only con- 

 sist of a tubercle placed at each side of the posterior part of the 

 head. These appendages are soon elongated and divided into 

 laminae ; the eyes are distinguishable through the skin, and a 

 transverse slit is seen under the neck, so as to form there a kind 



p p 



