256 



INTBODUCTION TO ZOOLOGY. 



Fig. 220. 



In the third {Fig. 221) the gills have disappeared, and the 

 respiratory circulation is carried on by the arteries of which 

 the development was exhibited in the previous figure. 



The Newts, Hke the 

 Frogs and Toads, are 

 carnivorous, preying upon 

 aquatic insects, larva, 

 worms, and moUusca ; 

 nor do the larger species 

 hesitate at laying hold 

 of and devouring their 

 weaker and smaller bre- 

 thren. The Tadpole of 

 the Frog forms also an 

 important item in their 

 bill of fare. 



When it is considered 

 that aU the amphibia 

 are harmless to man, 

 and many of them actually useful, by keeping in bounds 

 the diminutive assailants of his crops and pastures, it may 

 seem strange that they should have been so generally re- 

 garded as disgusting and pernicious. Perhaps no individual 

 among them has been so slandered as the Toad ; and if we did 

 not know, in other instances, how imagination takes the place 

 of reason, it might seem incredible that this unoffending reptile 

 should have been regarded as " highly poisonous, and this not 

 only from its bite — its breath and even its glance were fraught 

 with mischief or death."* It was natui-al, therefore, that 



* Bell's Reptiles. 



•j-'i. 



