THE CHUCKWALLA 243 



same individual, and apparently dependent on 

 the intensity of light to which the animal is 

 exposed/' 



Every part of the body is built for a purpose. 

 Though it appears queer in form, yet a study of 

 it will reveal that the chuckwalla is encumbered 

 with none of those useless and over-exaggerated 

 specialized structures which have so often 

 marked senescence among reptiles. The clumsy, 

 fat, blunt tail is his chief weapon of defense, 

 and he can flop it vigorously when occasion 

 demands that he use it. The smart blows he 

 gives cause all his enemies to take notice of him. 

 He looks lazy and stupid, but approach him and 

 see how quickly his short, stubby limbs enable 

 him to drop out of sight and into a place of 

 safety. The flat body makes it possible for him 

 to squeeze himself into extremely narrow cracks 

 in the rocks, and because of his loose, elastic 

 skin he is able to inflate himself so tightly that 

 not the strongest man can pull him out from 

 his place of safety. Rather will he surrender his 

 tail to Cerberus than give up his body to his 

 enemy. The lizard-eating Indians, the Sho- 

 shones, Cahuillas, and their near cousins the 



