NATURAL HISTORY IN ANECDOTE. 

 VERTEBRATA. 



CLASS IV — B ATRAC HI A. 



■The Class IV of the Vertebiata comprises the Batra- 



Batraohia. chia which are divided into three orders : I Pseu- 

 dophjdia, II Urodela, III Anura. The first order comprises 

 the limbless worm-like reptiles of the genus Caecilia of Africa 

 and South America ; the second includes the Newts and the 

 Salamanders ; the third the Frogs and the Toads. Leaving 

 the first two orders, we devote a few lines to the third, dealing 

 with the Toad, the Common Frog and the Tree Frog. The 

 members of this order are singular for the extraordinary changes 

 through which they pass between birth and maturity. As Tad- 

 poles, in which form they first reach life, they have thick black 

 legless bodies ending in tapering tails, and are provided with 

 the fishlike anatomy necessary to an aquatic existence. In the 

 process of development they completely change both in internal 

 arrangement and external appearance. The gills are exchanged 

 for lungs, the legs supersede the tail and the internal system 

 undergoes corresponding change. In the end the animal be- 

 comes semi-aquatic, capable of living under water for some 

 time, but compelled to come to the surface for air at intervals ; 

 and also of living out of the water altogether in such places as 

 afford sufficient moisture, damp being as necessary to their 

 comfort as food and air. They hybemate in the winter and 

 propagate in the spring ; and in times of drought burrow into 

 the earth and remain lethargic until rain falls. They feed on 



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