CONCERNING TADPOLES 



187 



-ef the frogs and toads known as the " Urodela " or " tailed 

 Batrachians," and in common speech as the " efts " or 

 " newts," and the " salamanders." These creatures 

 retain their tails throughout life, and display only a 

 " larval " stage : the tadpole phase of the frogs and toads 

 being more or less retained throughout life. 



Why is it 

 that the early 

 history of the 

 young newt, 

 or salaman- 

 der, is so 

 much more 

 simple and 

 direct than 

 is the case 

 with the frog 

 and its kind ? 

 We ask at 

 present in 

 vain, but such 

 is the case. 

 The young 

 newt develops 

 no-, sp eci al 

 mouth, like 

 the young 



frog, and fasts only for a brief period while the mouth 

 that is to last its lifetime undergoes its finishing touches : 

 the larval frog and the later tadpole are inky black, the 

 young newt is transparent. The larval newt breathes at 

 first by external gills, like many young fishes and larval 

 rogs ; but later these are exchanged, as in the case of 



STAGES IN THE DEVELOPMENT OF A NEWT 



{continued). 

 The stage shown at I answers to the pcrfnanent stage of 

 the curious S. American Axoiotl, wherein the external gills 

 are retained tliroughout life. 



