418 



COLLEGE ZOOLOGY 



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Figure 289. Rattlesnake. A radiograph showing the absence of hmbs, hmb girdles, and sternum, 

 but the numerous vertebrae and ribs are much alike in structure. Two rattles are visible at the 

 posterior end of the body. (Courtesy of Armed Forces Institute of Pathology, Washington 25, D.C.) 



but is not a water moccasin. The black snake 

 (Coluber) is a slender long-tailed snake 

 which reaches a length of 6 feet. West of 

 the Mississippi it gives way to a subspecies 

 called the blue racer and to another species, 

 the red racer, in Texas. Contrar}' to popular 

 belief, this reptile does not attack snakes 

 larger than itself, has no power to squeeze 

 its prey to death, and is unable to hypnotize 

 birds and squirrels. King snakes (Fig. 293) 

 are of various sizes; they are constrictors and 

 have received their common name because 

 they prey on other snakes. The scarlet or 



coral king snake resembles the venomous 

 coral snake in color. King snakes are im- 

 mune to pit viper venom, but not to coral 

 snake venom; hence they do not hesitate to 

 attack rattlesnakes, water moccasins, and 

 copperheads. The milk snake derives its 

 name from the erroneous supposition that 

 it steals milk from cows. The hog-nosed 

 snakes, Heterodon (Fig. 287B), are popu- 

 larly known as puflf adders, spreading vipers, 

 or blowsnakes. They are nonvenomous, 

 though they fiercely intimidate and also 

 play possum. 



