THE LIZARDS, SNAKES, AND OTHER REPTILES. 185 



middle of each caudal vertebra has a thin cartilaginous par- 

 tition, and it is at this point that the tails of these lizards 

 break ofE so easily when seized. In such cases the tail is 

 renewed, but is more stumpy. 



Both jaws are provided with teeth, while some have them 

 developed on the bones of the mouth. Most lizards prey 

 on insects ; some live on plants. The eyelids are well de- 

 veloped except in the Geckos, in which, as in the snakes, 

 there is a transparent sack filled with fluid over the cornea 

 or ball of the eyes. The tongue is free and long, some- 

 times forked ; in the iguana it ends in a horny point. 



Lizards lay their eggs in the sand or soil. The iguana. 



Fio. 190.— West Indian Gecko. 



or great lizard of the West Indies, deposits hers in the hol- 

 lows of trees. Certain kinds are viviparous. 



Our most common lizard in the Middle and Southern 

 States is Sceleporus undulatus; it is about six inches long, 

 gray, with dark wavy bands, and may be<^ seen in sunny 

 glades running up the trunks of trees. 



It is evident that this lizard is protected by its resem- 

 blance, when at rest, to the bark of the pine. The iguanas 

 are very large, being nearly three feet in length, but rather 

 sluggish lizards, with a dorsal row of high, thin spines. 

 They are said to be excellent eating. 



The "horned toads" {Phrynosoma, Fig. 191) are char- 

 acteristic of the dry Western plains ; the body is broad, 

 flattened, and spiny. Their color is like that of the soil 

 they inhabit ; hence, protected by their color and their 

 strong spines, they are probably not often snapped up by 

 birds. Like all other lizards, the horned toad can with- 



