196 AFFINITIES AND GEOGRAPHICAL 



are much larger than any existing lacertilia, the parent family ; 

 but it must be remembered that the early lizards were of 

 enormous bulk. Geology speaks in harmony with this view 

 of the genesis of the ophidia, no fossil serpent occurring in the 

 secondary formation, where all the other reptilian forms so 

 greatly abounded. Such harmonies may always be expected, 

 where the true track of natural investigation has been arrived at. 

 A naked moist skin, sometimes smooth, sometimes covered 

 with papillae or tubercles, is the only universal character of the 

 third division of the Reptiles the BATRACHIA, so called from 

 the Greek word for a frog, as that animal is the most conspi- 

 cuous example of the order. The animals of this order are 

 also remarkable for coming into active existence in a fish form 

 (the tadpole), and passing in the course of active life through 

 one of those metamorphoses which in the other animals are 

 undergone before birth. They realize, as has been said, before 

 our eyes, one of the grade transitions presumed by the deve- 

 lopment theory. In some species, certain portions of the or- 

 ganization are arrested at the fish stage, and so continue 

 through life. 



The frogs and toads (Ranidce) are the batrachians most uni- 

 versally diffused over the earth and most familiarly known. 

 They are harmless creatures, generally of small size, living upon 

 slugs and insects, which they catch by darting out their long 

 soft tongue, the end of which is, for this purpose, covered with 

 a viscid fluid. They hibernate in mud or water, thus living a 

 Ions; time, not only without food, but without aerial respira- 

 tion, a proof of the low organic character of these animals. The 

 frogs spend much of their time in water ; some assume a par- 

 tially arboreal life, and have certain peculiarities in the feet 

 which assist them in climbing. The toads are more terrestrial 

 in their habits ; but all alike have to propagate in the water, 

 where their shell-less eggs are deposited in long strings, a single 

 mother producing upwards of a thousand young. Some foreign 

 species of the ranidse greatly exceed ours in size ; but, in com- 

 parison with the two other reptilian orders, the batrachian 

 may be said to consist of little animals. Teeth are wanting in 

 most of the toads, and they are developed on a humble scale 

 in the frogs. The whole of the ranidae are destitute of tail ; 

 neither have their toes any armature, excepting a horny sheath 

 in a few species. They are also devoid of ribs, or present at 

 the most rudiments of such bones. 



The ungainly form of the toad has caused it to be no favourite 

 with our race, and given rise to many reports against it, par- 



