PLANT-EATING BIRDS, REPTILES, AMPHIBIANS, FISHES 193 



by means of which it can browse upon delicate algse, which are 

 found floating in slimy green masses in its native pond or ditch. 

 Later on, these beaks are cast off, and at the same time the 

 little pointed teeth characteristic of the adult frog are developed. 



Vol. II. 



45 



