REPTILES. 



253 



sion is, however, more temporary than that of many of 

 our cherished garden flowers. The tufted gills shrink in size, 

 until, like the gills of fishes, they are concealed within the 

 branchial sacs. The little Tadpole {Fig. 212) begins to feed 

 on decaying vegetable matter ; the tail has become a large 

 and powerful organ for locomotion, and a rapid increase in the 

 size of the body is perceptible. After a time the hinder feet 

 become developed {Fig. 218); then the anterior extremities 

 bud forth* {Fig. 214); the tail shrinks; the form of the 

 perfect animal is assumed {Fig. 215); the remaining vestige 

 of the tail disappears {Fig. 21G); and instead of an aquatic 

 animal breathing by gills, and subsisting on vegetables, we 

 have a terrestrial animal, breathing by lungs and altogether 

 carnivorous. 



Fig. 2U. 



Fig. 213. 





Fig. 215. 



Fig. 214. 



Fig. 2ie. 



The food of the Frog consists of insects of various kinds 

 and of small Slugs ; the number which is thus destroyed is so 

 considerable, that the Frog might prove a valuable assistant to 

 the farmer or the gardener. The manner in which the food is 

 taken is worthy of notice. In the Frogs, as in the Toad, the 

 tongue is doubled back on itself. The point, covered with a 

 viscid secretion, is thrown forwards upon the insect and 

 di'awn back again with such rapidity as scarcely to be detected 

 without careful watching. t 



In some of the countries of both temperate and tropical 

 regions there are Frogs which, from their habitation, are called 



* We are informed by a friend, who has watched the metamorphosis 

 with great attention, that the left fore leg is perfectly developed before the 

 other appears. 



t Bell's Keptiles. 



