POISONOUS SNAKES OF NORTH AMERICA. 379 



strike the object aimed at the poison is sometimes projected several feet. In one 

 case which is known to me, it was thrown into the eye of a man standing 5 or 6 feet 

 from the snake, when it struck upward at a stick held above its coil. 



The study of the complicated mechanism which we have endeavored to explain 

 will aid ns in understanding several points of interest in connection with the bite 

 of the rattlesnake. 



It must be perfectly ajjparent that in a sequence of movements so elaborate it will 

 occasionally happen that, from a failure in some one of the essential motions, the 

 ultimate purpose of the whole will be interfered with. Thus, it sometimes chances 

 that the serpent miscalculates the distance, and fails from this cause. Or, again, 

 when the object aimed at is very near, the initial force of the blow is lost, and the 

 tooth does not enter; no uncommon occurrence, where the animal struck is an old dog 

 with a tough skin. Again, if the upper jaw be not elevated sufficiently, the fangs 

 are sometimes driven backward, by the force of the forward impulse, as they touch 

 the part attacked, and the venom is then apt to escape between the tooth and the 

 fovering mucous cloak. Upon one occasion, having allowed a small snake to strike 

 a dog, the former became entangled, owing to the hooked teeth of the lower maxil- 

 lary bone having caught in the skin. Upon examining the snake closely, the dog 

 being held, I found that the convexity of the fangs lay against the skin, on which 

 were thrown one or two drops of venom. On remoA'ing the snake, and inspecting 

 the part struck, I could find no fang wound, although the skin was visibly torn by 

 the smaller teeth. I have seen the rattlesnake strike with great apparent ferocity, 

 a number of times, when I have been unable to discover any fang wound whatso- 

 ever, and this has taken place, occasionally, with small animals, such as the rabbit, 

 which must have been seriously eft'ected by even a small amount of venom. 



It scarcely ever happens that an animal is bitten without a part of the injected 

 venom being cast on the skin near the wound made by ihe fangs. This wasted 

 material probably escapes from the duct, where it is in opposition with the lower 

 opening of the fang canal, and may be merely that excess of fluid which the fang 

 can not carry. In some cases, however, it is quite possible that the relations of the 

 fang and the duct are so disturbed that the venom never enters the tooth at all. It 

 is certainly true, as has been already stated, and as Dr. Wyman has shown, that the 

 fang must be fully erected in order that the duct shall be so tirmly held in contact 

 with the fang, as to insure the passage of the venoui through this latter organ. 



Finally, it sometimes happens that the blow is given, the fang enters, and from 

 the quick starting of the animal injured, or from some other interrupting cause, it 

 is withdrawn so soon that the larger portion of the poison is thrown harmless upon 

 the surface near the g^vound. Under these circumstances, the resulting symptoms are, 

 of course, trifling, and how well such an occurrence would be calculated to deceive 

 the observer, who employed an antidote in a like case, can be readily conceived. 



In a more popular paper* Dr. Mitchell remarks that the nervous 

 mechanism which controls the act of striking seems to be in the spinal 

 cord, for if we cut off a snake's head and then pinch its tail the stump 

 of the neck returns and with some accuracy hits the hand of the experi- 

 menter if he has the nerve to hold on. A little Irishman who took care 

 of the doctor's laboratory astonished him by coolly sustaining the test, 

 but did it by closing his eyes and so shutting out for a moment the too 

 suggestive view of the returning stump. In the memoir previously 

 quoted, on the other hand, he mentions that in one or two instances 

 persons who were ignorant of the possibility of this movement have 

 been so terrified at the blow which has greeted them as to faint on the 



* Century Magazine, xxxviii, August, 1889, pp. 503-514. 



