308 VERTEBRATES I BATRACHIANS. 



made it the emblem of the protecting divinity of the 

 world, and sculptured it on the sides of a globe upon the 

 gates of their temples. By pressing this snake on the 

 nape, the jugglers of Egypt throw it into a stiff and 

 immovable condition, which they call turning it into a 

 rod. It is probably the Asp of Egypt, and Asp of Cleo- 

 patra. 



HYDROPHID^E, OR SEA-SNAKE FAMILY. This Family 

 comprises serpents which have the posterior parts of the 

 body and tail much compressed, and raised vertically. 

 They inhabit the warm parts of the Indian and Pacific 

 Oceans, and the streams of the East Indies, and are very 

 venomous. They are mainly of small size. 



SECTION IV. 



THE CLASS OF BATRACHIA, BATRACHIANS, OR AMPHIBIANS. 



THE Class of Batrachians comprises cool-blooded, ovip- 

 arous vertebrates which are destitute of scales, and which 

 in most cases lay their numerous eggs in the water or in 

 damp places,* and whose young hatch in an immature 

 condition, and afterwards undergo various changes before 

 they acquire the form of the parents. The young breathe 

 by gills similar to those of fishes, and in most cases live 

 in the water ; but in the adult state, these animals, with 

 few exceptions, breathe by lungs, like scaly reptiles. The 



* Some Tree-toads lay their eggs on trees and places overhanging water, 

 and the young, as soon as hatched, drop into the water. 



Pipa, or Surinam Toad, of South America, lays its eggs in the water, 

 after which they are collected by the male, and placed on the back of the 

 female, the skin enlarging in such a manner as to enclose the eggs in cells ; 

 here the development goes on till the young come forth as perfectly formed 

 toads. 



A small frog of Venezuela has a pouch upon the back in which the eggs 

 are carried and hatched. 



