CHAPTER XXIX. 



Amphibia {Frogs and Toads). 



"To any person," observes the eloquent historian of 

 British Reptiles, " capable of appreciating the interest at- 

 tached to the study of physiological phenomena, the con- 

 templation of an animal which at one period of its life is 

 endowed exclusively with the organs of aquatic respira- 

 tion, resembling the gills of fishes, with means of locomo- 

 tion adapted only to a constant residence in the water, 

 and with a digestive apparatus fitted exclusively for the 

 assimilation of vegetable food, assuming by degrees the 

 function of atmospheric respiration, acquiring limbs which 

 are formed for leaping on laud with great strength and 

 agility, and manifesting the most voracious carnivorous 

 appetite, will not only excite feelings of the deepest admi- 

 ration, but necessarily lead to the investigation of the 

 laws by which such extraordinary changes are governed, 

 and of the relations which they bear to the theory of 

 continuous affinity, and to that of progressive develop- 

 ment through the whole of the animal kingdom. "* 



Such phenomena are exhibited by the Toads, Frogs, 

 and Newts, the familiar representatives of that limited 



* Bell's "Brit. Bept.,"p. 72. 



