THE FROG 163 
Its mouth is on the front under surface of its head, a 
position which enables it to nibble at the soft parts of the 
water plants, upon which it feeds. The tadpole grows 
with considerable rapidity, and, at the end of some weeks, 
(from four to eight) two small swellings begin to make 
their appearance one on either side of the body near its 
junction with the tail. The length of time which elapses: 
before this change occurs will depend on the weather, 
warm, genial weather favouring a rapid development. 
The swellings referred to gradually increase in size, and 
finally take the form of limbs, which greatly assist the 
Tadpole in swimming. As the hind limbs are forming, two 
other swellings make their appearance, one on either side 
of the body near the head. These, too, grow rapidly, and 
at last forcing their way through the skin appear as a pair 
of forelimbs. In the meantime, the tail has been getting 
smaller, and usually by the time the four limbs are fully 
formed has disappeared altogether. 
The whole appearance of the creature has now changed ; 
its head and body have grown large and broad; its eyes 
stand out prominently, and its mouth is quite in front of 
its head. Changes, too, are taking place in its internal 
organs, fitting the animal for its life on land; the gills 
gradually close up, and lungs begin to form inside. 
Not. —The tail is not cast off, but gradually absorbed during 
the period of transformation. 
The Tadpole has now been transformed into a Frog ; it no 
longer cares for the vegetation of the water-pools, for it 
has become a flesh-eater. Small at first, it grows rapidly, 
shedding its skin from time to time, as this becomes too 
small for its increasing size. The older skins, as they are 
cast, are devoured by the animal itself. 
