THEE- TOADS. 
185 
Spawn at two seasons instead of one, and that their larv88 
attain a greater size than those of other frogs before com- 
pleting their metamorphosis. 
Among the tree-toads, Polypedates of tropical Western 
Africa, contrary to the nsual habits of frogs, deposits its 
eggs in a mass of jelly attached to the leayes of trees which 
border the shore overhanging a pond. On the arrival of 
the rainy season, the eggs become washed into the pond 
below, where they develop. Our common piping tree-toad 
{Hyla Picheringii), about the middle of Apiil, in the 
Northern States, attaches her eggs singly to aquatic plants. 
The young are hatched in about twelve days. 
Miss Hinckley has described the habits of the larger tree- 
toad {Hyla versicolor, Fig. 231). The eggs are attached 
from early May till July, singly and in small groups in 
grass which grows up and rests on the water. The tadi3oles 
hatch in two days. In a week after the tadpoles appear 
the gills are absorbed. Meanwhile the tadpoles hang by 
their holders," or suckers on the lips, to the leaves, as 
seen in the engraving. When about three weeks old the 
hind legs begin to bud out in front of the base of the tail. 
During the eighth week they take little food; the four legs 
grow out, the tail disappears, the mouth becomes adapted 
for seizing and eating insects, and they leave the water. 
This tree-toad depends for safety on its power of changing 
its color from green to gray; it hides among leaves, or in 
crevices in the bark of trees, when it becomes ^Mike a 
part of the bark of the tree." 
As an example of what is called a suppressed metamor- 
phosis may be cited the case of a tree-toad in the island of 
Guadaloupe. There are no marshes on this island, conse- 
quently in a species of Hylodes the development of the 
young is direct; they hatch from the eggs which are laid 
under moist leaves, without tails, and are otherwise, ex- 
cept in size, like the adults. On the other hand, a tree- 
toad of the island of Martinique {Hylodes Marti nicensis, 
Fig. 232) has tadpoles, which it carries on its back. The 
