140 YEARBOOK, PUBLIC MUSEUM, MILWAUKEE [Vol. III. 



"The important fact should be understood that an arm or leg bitten 

 by a poisonous snake is very susceptible to common bloodpoisoning (sep- 

 ticaemia), owing to the deadening effect which the venom produces upon 

 the organisms ifi the blood that combat germ life. The effect of such a 

 compHcation, as blood-poisoning upon a system weakened by the 

 primary ordeal, may be imagined."*^ 



The item of immunity from snake venom can be briefly disposed 

 of. From the preceding paragraphs of this article it may readily be 

 seen that it is not natural for man to enjoy immunity from rattlesnake 

 poison. Some individuals may be affected to a less degree than others, 

 depending upon the general vitality and susceptibility of the individ- 

 ual. In the case of lower animals it is recognized that the domestic 

 pig "will destroy and eat rattlesnakes with impunity. It is said that 

 the poison is not sufficiently introduced into the circulation to cause 

 death, owing to the thick adipose layer with which the pig is covered. "^^ 

 Venomous snakes are apparently immune to their own and each other's 

 poison and they do not try to injure one another by biting. Dr. S. 

 Wier Mitchell of Philadelphia in his monograph*^ cites a number of 

 interesting experiments in this respect. He describes instances where 

 he had repeatedly injected under the skin of a rattlesnake its own 

 venom or that of a moccasin, or of another rattlesnake, but he had in 

 no case seen a death. He says he often kept from ten to thirty-five 

 rattlesnakes together without any of them harming the others. If 

 a large snake were suddenly dropped on the others they would show 

 no resentment, whereas if any other animal were thus dropped on 

 them it would inlmediately get a blow. 



The virulency of rattlesnake poison should likewise receive some 

 consideration in view of all of the preceding. The potency of the 

 venom will be found to be dependent upon a great number of factors 

 principally involving the size and vitality of both snake and victim. 

 Large animals, such as a man or a dog, may be affected to a less degree 

 than smaller animals. The size of the snake, the probable amount 

 of poison injected, the location of the wound, the state of the blood 

 and susceptibility of the victim and even the period elapsing since 

 the last bite of the snake must be taken into consideration. The 

 amount of venom contained in the poison glands of a rattlesnake ob- 

 viousl}^ varies with the size of the snake and the period since it was 

 last disturbed and used its venom apparatus. Of all warm-blooded 

 animals, birds are apparently the most susceptible to Crotalus poison 



"Ibid., pp. 406—408. 



«Cope, E. D. Op. Cit. p. 1151. 



""Researches upon the Venom of the Rattlesnake," Philadelphia, 1860. 



