LIZARDS 71 



yellow ochre on the sides, even the gloss of the black lava 

 being imitated. 



Although dependant on very great heat during the day- 

 time, when they move about with some rapidity, at night, 

 having retired into the sand, they are able to withstand 

 very severe cold, Ph. hernandezi^ of Mexico, for instance, 

 being found at an altitude of over 10,000 feet, where, of 

 course, many degrees of frost are registered nightly. 



In captivity, unless provided with a very high tempera- 

 ture, they are sluggish, remaining for hours in the same 

 position and refusing their food, which consists of various 

 small insects. 



When on the defensive these lizards generally merely 

 flatten their bodies and become quite rigid, giving one 

 the impression of simulating death. A curious fact 

 has, however, been observed in some individuals, such 

 specimens, when alarmed, squirting fine jets of blood from 

 the corner of their eyes to a distance of several feet. 

 Prof. Underwood has given the following account of this 

 remarkable habit : " In examining a specimen, I took 

 occasion to turn him on his back, using a lead pencil for 

 the purpose. The animal resented this treatment, and 

 showed considerable anger, opening his mouth and puffing 

 his body. Irritating the creature still more, he grew more 

 and more enraged, until finally blood spurted from just 

 above his eye, which was fired at least a foot from the 

 animal, as several spots struck my arm considerably above 

 my wrist. After spurting the blood the animal became 

 limp and collapsed, and remained in stupor for some time, 

 and when handled became as dead. After a time, possibly 

 not over five or six minutes, certainly not over ten, the 



