274 
LIFE. IN ITS HIGHER FORMS. 
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 th 
assimilation of vegetable food, assuming by degrees the 
function of atmospheric respiration, acquiring limbs which 
are formed for leaping on land 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 
* Bull's “ Brit. Kept.,” p 72. 
