74 ECAUDATA. 



mucilaginous chords, and when liatched they produce Tadpoles or animals 

 unhke the parents. 



9. Tadpoles have very large heads, confounded with a short, thick body, and 

 have long compressed tails, and breathe with gills. They undergo a complete 

 metamorphosis; the tail disappears and is succeeded by anterior and posterior 

 extremities; the gills disappear, and their place is supplied by lungs, &c.; 

 and these changes are always accompanied by alterations equally important 

 in the internal organization of the animal. At first the Tadpole is aquatic 

 and breathes with gills, like a fish; but after its metamorphosis it respires 

 atmospheric air only, by means of lungs. As a Tadpole, it lives on vegetable 

 matter, and its organization is in accordance; as a perfect animal it is 

 carnivorous, its food being different; the alimentary canal is now shortened 

 and otherwise altered in its arrangement, and it is wonderful to observe the 

 ease with which nature changes an herbivorous to a carnivorous animal. 



The Ecaudate batrachian animals have been arranged in two sections. 1. 

 Those without a tongue (Aglossae), of which none exist in our country; and 2. 

 Those furnished with a tongue (Phaneroylossae), which are very numerous, and 

 may well be grouped in three families — Ranoidea, Hyloidea, and Bufonoidea. 



