42 INTRODUCTION 



Many kinds of reptiles vary so much that it is difficult to 

 find two specimens which are quite alike in color and 

 squamation. Sometimes the variations correspond with 

 definite geographical areas, as in the genera Cnemidophorus, 

 Phrynosoma, Gerrhonotus, and Thamnophis, but frequently 

 they are purely individual. Many reptiles and amphibians 

 are subject to chameleonic changes, or changes in accordance 

 with the intensity of the light, or with the colors of objects 

 by which they are surrounded. For these reasons, the col- 

 lector should strive to secure many specimens of each 

 species. 



Reptiles are to be found in all sorts of situations. The 

 collector should study their habits if he would be successful 

 in his search. Some kinds prefer moist places, while others 

 are most abundant on barren hillsides or on the open desert. 

 As a rule, reptiles like sunlight and warmth, but some spe- 

 cies live in the thicker forests, and not a few are nocturnal. 

 Amphibians usually are found in moist places, often actu- 

 ally in water. 



Some reptiles and amphibians may be caught with the 

 hands unaided by any apparatus. Other species, too agile 

 to be captured thus, may be secured by means of a slip-noose 

 of horse-hair, wild-oats, thread, or fine wire, deftly placed 

 over the head of the victim and then tightened with a sud- 

 den jerk. However, by far the most satisfactory method of 

 procuring reptiles and frogs is to shoot them. For this 

 purpose small charges of fine shot are used in an auxiliary 

 barrel, collecting pistol, or small caliber rifle. The last will 

 prove much more eflFective if the rifling has been removed. 

 When taken in the hands our reptiles often bite fiercely, but 

 even if they succeed in drawing blood, none except the rattle- 

 snakes, the coral snake and the Gila Monster can cause any 

 serious injury, for only these are poisonous. 



Nothing is better for preserving reptiles than alcohol, 

 though formalin may sometimes be used when little space 



