ur common species
lay their eggs in water, the eggs being fertilized as they are laid. As
the eggs are laid they are inclosed in a gelatinous envelope secreted
by the female. This swells and protects the eggs from injury, from
being fed upon, from the direct rays of the sun, and in some species it
serves to float the eggs at the surface of the water, where oxygen is
most abundant; finally, the envelope serves as food for the young
frogs. The mouth of the tadpole is small and provided with a horny
beak, which takes the place of the teeth which are not yet developed.
The tadpole feeds on algae that cover stones, and on the flesh of dead
animals. The long, spirally coiled intestine, which can be seen on the
under side of the animal, is an adaptation to its prevailingly
herbivorous diet, which requires a prolonged digestion.

The tadpole usually lives in the water for two or three months before
it takes to land. In the Bullfrog, however, the transformation (see
TOAD) does not take place until the second summer.

In many tropical Frogs the reproductive habits are much modified. One
species (_Phyllobates trinitatis_) of Venezuela and Trinidad carries
its tadpoles on its back, to which the young attach themselves by means
of their suckers. A frog of the Seychelles Islands lives in the
tree-ferns far from water, and carries its young about on its back, to
which they are attached by their bellies. In the Kameruns lives a Frog
that lays its eggs in a foamy mass on the leaves of a tree. When the
larvae are developed the mass becomes slimy and the tadpoles swim about
it, and when a heavy rain falls they are washed into pools of water
lying at the bases of the trees. The foam is probably produced as it is
in culinary operations, by air being entangled in it by a beating that
the Frog gives the jelly with its feet. The inclosed air may well serve
in respiration. Compare TOAD.

UTILITIES. Among both civilized and savage men Frogs are a culinary
dainty. The edible European Frog is so much prized in France that it is
bred for the market in large preserves. In the United States both the
Bullfrog and spring Frog are sold in the markets. In France and the
United States the hind legs alone are eaten; they are known as
"saddles" to American marketmen, and are usually served at table fried.
In Germany all the muscular parts are served stewed, often with sauce.
Frogs have enabled man to contribute much to his knowledge of
physiology. The ta