THE SAND LIZARD, LACERTA AGILIS 63 



Haunts. — The popular name of sand lizard in this 

 case appears to rest upon a good foundation, sandy 

 districts it undoubtedly affects. There is good reason 

 for this in connection with the two physiological pro- 

 cesses in this species of reproduction and hibernation. 

 The warmth of the sand assists the former — for in 

 this case the eggs are deposited early, while the ease 

 with which it can burrow in loose sandy soil assists 

 in hibernation. Sunshine is a much more necessary 

 condition of life to the sand lizard than to the slow- 

 worm, hence the former keeps to the open and un- 

 disturbed sandy heaths and commons, with sunny 

 banks on which to bask. Much of its life is passed 

 underground, and on the slightest approach of cold it 

 retreats from exposure to air. But on bright warm 

 days the sunniest spot in its local habitat will find the 

 sand lizard deriving all the heat it can for its cold- 

 blooded system from the sun. it is a dweller in 

 plains rather than mountains. 



Habits. — There is always the danger in attempting 

 to give an account of the character and disposition of 

 an animal, that its behaviour in captivity, i.e. under 

 artificial conditions, is assumed to be identical with 

 that in the natural wild state. Further, we know 

 that in some reptiles, the adder for example,^ the 

 effect of captivity upon the character is very marked. 

 But the great difficulty has to be faced that it is 

 practically impossible to watch some creatures in 

 ^ Field Naturalist's Quarterly, vol. i. No. 1. 



