12 BRITISH LIZARDS 



modified. The intestine is relatively short in the 

 carnivorous, long in the herbivorous species. But 

 swiftness, the apparatus necessary for climbing, run- 

 ning, and digging, the mechanism of the tongue, the 

 armament and muscles of the jaws, stand also in 

 correlation with the kind of food and with the way 

 in which it has to be procured." ^ 



In colouring the lizards present again immense 

 variation, according to their habitat. Those which 

 are dwellers in deserts approximate to the colour of 

 the sandy surroundings, being brownish or yellowish 

 red. Many which live amongst luxurious vegetation 

 are brilliantly coloured, and a large number have the 

 power of more or less changing their hue, a character- 

 istic particularly associated with the Chameleon family. 

 A curious property of many lizards is the readiness 

 with which a portion of the tail breaks off, and the 

 capacity for reproducing more or less perfectly the 

 lost portion, the regenerated part differing, however, 

 in some details from the original tail. Like the 

 snakes, lizards cast their slough periodically, some- 

 times whole, sometimes in pieces. Taking the 

 Lacertilia as a whole, the majority reproduce their 

 young by depositing eggs, that is, they are oviparous, 

 the " shell " being either hard (as in the green lizard 

 and the sand lizard) or more membraneous. These 

 latter eggs increase in size after being deposited, from 

 the taking in of moisture. Other species lay their 

 * Dr. Gadow, Amphibia and Reptiles, p. 492. 



