286 REPTILES. 



their body, so as to render it tense and elastic, and cause the skin to pour 

 out a white and acrid fluid. Sometimes they endeavour to defend themselves 

 by biting, but their mouth is quite destitute of teeth. These hideous reptiles 

 generally conceal themselves in shady humid places, from which they do not 

 go out except at night, or immediately after the warm and abundant rains of 

 summer. Like frogs, they feed on small Mollusks, worms, and living in- 

 sects, but they are more terrestrial in their habits. They betake themselves 

 in summer to pools and streams, where the females resort to deposit their 

 eggs. In countries where the winter is cold, they pass the season in holes in 

 a benumbed state. Their respiration then becomes extremely limited, and 

 the contact of a very small quantity of air with the skin is sufficient to main- 

 tain their existence. When placed in situations where evaporation is very 

 inconsiderable, they can live in this way for a long time. This explains how 

 it is that toads enclosed in plaster, or shut up in holes excavated in stones, 

 are often found alive after many months of confinement. 



FIG. 309. --PIPAS. 



The Pipas are still more hideous than the toads. Their body is more flat- 

 tened, the head triangular, the eyes very small, their hind legs short, and their 

 anterior toes split at the end into three or four points. The tongue is entirely 

 wanting. The species best known inhabits the warm and humid parts of 

 South America, and is remarkable on account of the manner in which its 

 young are developed. The male places the eggs on the back of the female, 

 who immediately takes to the water, where her skin swells and forms cells, 

 wherein the young are hatched, and remain until they have completed their 

 metamorphosis ; then the mother returns to land. 



