178 ANIMAL BIOLOGY 



are left to shift for themselves which they are abundantly 

 able to do upon their first appearance on the stage of life. 

 Snakes in general are useful animals since they destroy 

 large numbers of injurious insects; they are also enemies 

 of mice, gophers, and other destructive small mammals. 

 The bite of most species is scarcely painful, although there 

 are several forms which have a well-deserved reputation 

 for being dangerous. The most common of the venomous 

 snakes of North America are the rattlesnakes which are 

 provided with a jointed, horny rattle at the end of the tail, 

 by which they make their peculiar rattling sound, when 

 disturbed. This sound serves as a warning which all 

 creatures that know what it means are only too ready to 

 heed; it may be a service to the snake also in frightening 

 away larger animals that might otherwise trample upon it. 

 The poison of the rattlesnake is secreted by two large 

 glands whose ducts lead to the base of a pair of large 

 perforated fangs through which the poison is injected into 

 the bite. 



The bite of the rattlesnake has frequently resulted in 

 death, and in all cases it should receive prompt treatment. 

 A tight bandage should first be applied between the wound 

 and the heart so as to check the return flow of blood in 

 the veins, and the wound should be induced to bleed freely. 

 Blood should be sucked from the wound and permanga- 

 nate of potash should be administered either by injecting 

 a solution into the wound or by rubbing in the crystals. 

 Brandy and whisky have been much over- rated as reme- 

 dies for snake bites, although they may be of value in 

 stimulating the heart action, for snake venom acts as a 

 heart poison. 



The only poisonous snake in the United States, except 

 those belonging to the rattlesnake family is the coral snake 

 of the South, which is black with seventeen rings of red, 



