580 AMPHIBIA. 
THE FROG AS A TYPE OF AMPHIBIANS 
The common British frog (Rana temporaria) and the 
frequently imported continental species (A. esculenta) agree 
in essential features. 
Though aquatic in youth, they often live in dry places, 
hiding in great drought, reappearing when the rain returns. 
Every one knows how they sit with humped back, how they 
leap, how they swim. They feed on living insects and slugs. 
Fic. 312,—The edible frog (Rana esculenta). 
These are caught by the large viscid tongue, which, being 
fixed in front of the mouth and free behind, can be jerked 
out to some distance, and with even greater rapidity re- 
tracted. When a frog is breathing, the nostrils are alternately 
opened and closed, the under side of the throat is 
rhythmically expanded and compressed, the mouth re- 
mains shut meanwhile. The males trumpet in the 
early spring to their feebly responsive mates. In our 
British species the pairing takes place soon after; the 
young are familiarly known as tadpoles, and a notable 
metainorphosis takes place. In winter the frogs hiber- 
