78 PHYSIOLOGY AND TOXICOLOGY 



but is oftener more superficial. So far as a fatal result is concerned, it seems to be 

 indifferent, whether the bite takes place about the head and neck, or in the limbs.^ 

 The local quivering which is so common, seems to depend upon the muscles of the 

 part having been wounded and envenomed, whereas, when the venom enters 

 only the areolar or adipose tissue, this symptom either does not occur at all, or 

 occurs only after a time. The swelling, which in a large majority of cases sur- 

 rounds the wound, is never inflammatory in the first instance, at least in animals, 

 and especially in those which die, and in which the rapidly increasing loss of tones 

 forbids the presence of such a condition. In some of the animals who recover, 

 secondary inflammation and gangrene, with more or less formation of pus may 

 ensue. The primary swelling, then, is always due to a collection of blood, some- 

 times partially coagulated, at others perfectly fluid, and apt to leak drop by drop, 

 out of the open fang track, when the opening is large, and the part bitten is highly 

 vascular. 



The effusion of blood in such large quantities as sometimes takes place, is ex- 

 plained by the rapidity with which its fibrin undergoes destruction at high tempe- 

 ratures (100° F.), and in the presence of such amounts of venom as are occasionally 

 injected. Under these circumstances the usual arrest of hemorrhage by coagulation 

 of the fibrin of the blood fails to take place, and the incoagulable blood soaks 

 through all the neighboring tissues. 



In other instances, as we have seen, the blood about the wound clots, owing 

 either to the relatively small amount of venom present, or to the fact of a sudden 

 and great escape of blood from some vessel of larger size than is usually punctured 

 by the fang. In no case are the clots thus formed of very firm texture." 



The veins about the wound are commonly found to be filled with dark and un- 

 coagulable blood, so that the effect here described, is exerted not only upon the 

 efl'used fluid, but also upon that which is still retained within the vessels. 



Effect of the Venom on the Muscles. — The influence of the venom upon the muscles 

 of the wounded part has been already described. It appears to be due to the direct 

 action of the venom upon the sarcous elements. 



As I supposed it possible, however, that the mere puncture might be competent 

 to cause protracted local quivering, I punctured exposed muscles, with dry fangs, 

 previously boiled, and then stopped with wax. Slight twitches followed, but no 

 further results were visible. When, on the other hand, I exposed the living muscle 

 and moistened it with venom, the twitching took place as usual, while, when the 

 venom was injected through the fang into the interior of the muscle, the convulsive 

 quivering was yet more active and prolonged. To ascertain whether or not this 

 was due to direct stimulation of the muscular tissue, or to an indirect influence 

 first affecting the nerves of the part, I executed the following experiment : — 



» Unless the mere swelling destroys life, or the poison be deposited near a large vessel. 



=> It is said that the pig is not liable to die from Crotalus bite, and it is well known that it attacks the 

 Rattlesnake with vigor and success. Its comparative immunity may, possibly, be due to the fact that its 

 skin is very thick and tough, and that the large deposit of sub-cuticular adipose tissue is scantily supplied 

 with bloodvessels. Notwithstanding this, I am assured upon competent authority, that when the pig is 

 struck in thin and vascular parts it enjoys no peculiar privilege. 



