THE BATRACIAN AMPHIBIA^ OR FROGS. 87 



are united, in their early age^ brancliia or gills, which 

 are subsequently lost. The young are called tadpoles^ 

 and are to be seen in all ponds and still waters during 

 summer : in this state they are provided with a tail, 

 something similar to that of fishes ; but this also is 

 lost in the adult^ since no vestige of this member has 

 yet been discovered in any of the species of full-grown 

 frogs. The body_, as in all the amphibians, has neither 

 scales nor plates^ but is covered by a cold naked skin^ and 

 there are no traces of ribs. The vital principle in these 

 reptiles is nearly as great as in the tortoises, and they 

 are killed with much difficulty. The heart contracts and 

 dilates a long time after the death of the animal^ even 

 after it has been extracted from the body. There is^ 

 however, such cold-blooded cruelty in the experiments 

 which have been made upon these harmless beings, that 

 we shall neither disgust our readers by further details_, 

 or perpetuate the shame of those whose philosophic 

 barbarity has furnished them. Much has been said 

 about frogs and toads remaining enclosed in hollows of 

 trees, and even in solid marble ; but the vulgar are 

 prone to believe the marvellous. That some of these 

 animals remain in a torpid and death-like sleep during 

 winter is well known ; and this lethargy is so profound, 

 that Hearne, in his voyage to the Icy Sea, mentions his 

 having found frozen frogs who exhibited no signs of 

 life when their legs were broken, although they re- 

 sumed their natural movements when exposed to a 

 genial heat. During this lethargy it njight possibly 

 happen that the aperture, by which the animal crept 

 into its winter retreat, would contract so much from 

 natural or other causes, that the reptile could not force 

 , itself out by the same passage at the return of spring : 

 it would therefore remain enclosed; and as we know 

 that all hybernating animals can remain without food 

 for a considerable time, it is not at all surprising that 

 frogs and toads should be found alive, so enclosed, 

 without the power of deriving nourishment. But even 



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