12 



INTRODUCTION. 



acts as an organ of prehension in most tailless Batra- 

 chians ; in the Disco gloss Idas, however, as in the 

 newts and salamanders, the tongue is entirely or 

 nearly entirely adherent to the floor of the mouth, 

 and the prey is seized by the jaws. The tongue 

 serves also as an organ of taste, for although frogs 

 seize almost any moving object, they will reject 

 before deglutition anything that is noxious to them, 

 as may be witnessed on offering a frog a brandling 

 or manure- worm (Alloloboplwra foetida), a ladybird 

 beetle, or a young Bombinator. Before being swal- 

 lowed, the food, if it be a small mollusc, crustacean, 

 or hard beetle, is crushed between the tongue, the 

 depressed eyeballs, and the vomerine teeth ; if the 

 latter be absent, as in Bufo, the sharp, sometimes 



Fig. 3. 



D 



Open mouths of — A. Discoglossus pictus B. Bufo ealamita. c. Ilyla 

 arborea. D. Rana temporaria. Showing the shape of the tongue 

 and the disposition of the choanae, Eustachian tubes, and vomerine 

 teeth. 



serrated edge of the palatine bones supplies their 

 function. The tongue is circular and entire in the 



