CHOKDA'l A 



313 



dorsal is usually covered with small scales; in these two points, 

 also, we shall see that the lizards differ from the snakes. Tiny 

 are mostly oviparous, the ova being inclosed in a parchmenl 

 like shell, but some are viviparous. The shape of the tongue 



FIG, 321. Anguis fragilis, a legless lizard, the blindworm, slightly reduced. (Alter Shipley 



and MacBride.) 



varies greatly, and this is made the basis of the further sub- 

 divisions of the group. In some species it is short, thick, and 

 not protrusible, in others it is vermiform, greatly elongated, and 

 protrusible, and in some it is bifid and slender as in the serpents. 

 The majority feed upon insects, worms, and other small animals, 

 while some are entirely vegetarian in their diet. Some are 

 capable of producing sounds. The tail is usually very fragile 

 and when lost can be regenerated; some species have been 

 known to bite off their own tails. 



Lizards are most abundant in the tropics, but they are also 

 numerous in many temperate countries; thev vary in size from 

 a few centimeters in length to two meters or more. Many of 

 the larger species are used as articles of food. Although many 

 are very repulsive in appearance, they are for the most part per- 

 fectly harmless animals, and in fact the bite of only one species 

 is known to be poisonous. The geckos (Fig. 322) and their 

 allies have curious adhesive discs on their feet, so that they can 

 run up the side of a smooth wall or tree; some of them have 

 folds of skin along the sides of the body, which they open out 



