204. BACKBONED ANIMALS. 
places the eggs on the female’s back, where they become imbedded, 
cells growing up around them, the mother lying in the mud until they 
appear, when a strange spectacle is seen, the young leaping from their 
prisons in all directions. 
Frogs (Ranide).—The frogs are the highest forms 
of the order. The upper jaw and palate have fine, sharp 
teeth (Fig. 237), and the throats of the males are provided 
with vocal sacs. The bull, marsh, and pickerel frogs are 
our common species. Their eggs are laid in masses in 
the water in April, May, and June. They hibernate in 
the mud during the winter. The bull-frog has been known 
to attain a length of two feet, and its noise can be heard 
for over a mile. They mimic the color of the rushes of 
the river-side in which they live. Their geographical dis- 
tribution is wide. One species is found living in the hot 
springs of Pisa where the temperature is 115° Fahr. They 
live upon insects, but the great Indian tiger-frog has been 
observed to capture sparrows. The American leopard- 
frog is one of the most active, leaping ten or twelve feet 
at a single bound. In the paradoxical frog of South 
America, the larva, instead of growing, decreases in size 
to attain the adult shape. 
VALUE.—The capture of edible frogs forms a valuable industry in 
France. 
Works on Amphibians for further reference. 
“Smithsonian Reports”; Holbrook’s ‘‘ Herpetology of North 
America”; Allen’s “ List of Reptiles and Batrachians near Spring- 
field, Massachusetts ” ; Huxley’s ‘‘ Vertebrates.” 
Class V.i—TRUE REPTILES. SNAKES, LIZARDS, etc. 
(Reptilia). 
General Characteristics—The true reptiles, snakes, 
lizards, and turtles, are distinguished from the Amphibians 
by having scaled bodies, clawed limbs, and by not passing 
through a metamorphosis or tadpole stage, developing 
