184 
ZOOLOGY^ 
sacs resting against tlie sides of the body; when the animal 
leaves the water they are absorbed, leaving a scar (Fig. 230). 
Siphonops Mexicana is a Mexican form. 
Order 5. Amira (Toads and Frogs). — These are the tail- 
less Batrachians. Frogs either live in or by the edge of 
pools and brooks, and when attacked on land they can by 
vigorous leaps escape to a place of safety. Unlike other 
Amphibians, they are powerful leapers, the legs being mus- 
cular, and their toes very long. The lower jaw is usually 
toothless. The larvso are called tadpoles, and represent 
the permanent, adult form of the salamanders. The 
mouth of tadpoles (Fig. 225, A) is small, almost minute, 
the lips armed with horny plates. They nibble dead leaves, 
while the mature animal has a very large mouth with teeth, 
and is carnivorous. The transformation of form of the 
mouth and digestive organs is as remarkable as in the but- 
terfly. 
Among the lower frogs are certain tropical forms, as 
Alytes, Pelohates, and Pelodytes, whose breeding habits are 
peculiar and interesting. The eggs of Pclodytes are de- 
posited in small clusters in the water, those of Peloiates in 
a thick loop. The male of the European Alytes obstetricans 
winds a string of eggs which it takes from the female, and 
goes into the water, where it remains until the young 
(which have no gills) are hatched. The American Scaph- 
iopus, or spade-footed toad, is not known to have this 
habit. This singular toad appears suddenly and in great 
numbers. It remains but a day or two in the water, where 
it lays its eggs in bunches from one to three inches in di- 
ameter. The tadpoles hatch in about six days after the 
eggs are laid; their growth is rapid, the young toads leav- 
ing the water in two or three weeks. The croaking of this 
toad is harsh, peculiar, and need not be confounded with 
that of any other species. As the spade-footed toads are 
rarely seen, it is possible that they burrow in the soil, like 
the European Alytes. Another peculiarity in the habits 
of Alytes, Pelolates, Ciiltripes, and Pelodytes is that they 
