152 PHYTOTOXINS AND ZOOTOXINS 



the north, Lacheris lanceolatus of Central America and Mexico being 

 nearly as dangerous as the cobra. 



When venom is taken into the stomach in the intervals of diges- 

 tion, enough may be absorbed to produce death, especially in the case 

 of those venoms which contain a large proportion of the albumose, 

 which is dialyzable ; but during active digestion the venom undergoes 

 alteration and is rendered harmless. It has been found experimen- 

 tally in animals that cobra venom placed in the stomach causes ordi- 

 narily no harm whatever, but if a loop of the intestine is isolated, a 

 fistula established and allowed to heal, venom introduced through 

 this opening always produces death. It is probably not so much 

 the pepsin and hydrochloric acid that destroys the venom, as the 

 trypsin. If the bile-duct is ligated, the venom is destroyed just 

 the same. Much of the venom seems to be eliminated into the stom- 

 ach, no matter how it is introduced into the system, and apparently 

 it is also partly excreted by the kidneys. Rattlesnake venom seems 

 not to be absorbed through mucous membranes. 



Physiological Action. — As indicated in the preceding paragraph, 

 the effects of the bites of different classes of snakes are quite differ- 

 ent. Langmann describes the symptoms as follows: 



Cobra Poisoning. — ^"\'\'itliin an hour, on an averajje, the first constitutional 

 symptoms appear: a pronounced vertigo, quickly followed by weakness of the 

 legs, which is increased to paraplegia, ptosis, falling of the jaw with paralysis 

 of the tongue and epiglottis; at the same time there exists an inability to speak 

 and swallow, with fully preserved sensorium. The symptoms thus resemble those 

 of an acute bul)>ar paralysis. The pulse is of moderate strength until a few 

 minutes after the cessation of respiration ; the latter becomes slower, labored, 

 and more and more superficial until it dies out almost imperceptibly. Death 

 occurs at the latest within fifteen hours; in 32 per cent, of all cases in three 

 hours. There are very few local changes." Cushny sna finds that cobra venom 

 produces paralysis of the motor nerve terminations of muscle, resembling the 

 action of curare ; the central nervous system is not directly involved. Death re- 

 sults from failure of tlie motor nerve ends in the respiratory muscles to transmit 

 impulses to the muscles. Alkaloids that are antagonistic to curare (physostig- 

 mine, guanidine) are not eff"ective in cobra poisoning, but are themselves rendered 

 inactive. 



Viper Poisoning. — "After the bite of a viper the local changes are most pro- 

 nounced; there are violent pains in the bleeding wound, hemorrhagic discolora- 

 tion of its surroundings, bloody exudations on all the mucous memln-anes, and 

 hemoglobinuria. Usually somewliat later than in cobra poisoninir constitutional 

 symptoms develop; viz., great prostration with nansea and vomiting, blood pres- 

 sure falls continuously, and respiration grows slow and stertorous. After a tem- 

 porary increase in reflexes, paresis supervenes, with paraplegia of tlie lower ex- 

 tremities, (>xtending in an upward direction and ending in a comiilete ))aralysis. 

 It therefore rescmliles an acute ascending spinal paralysis. If tlio patient re- 

 covers from tlie paralysis, a septic fccr may develop; not rarely there remain 

 suppurating gangrenous wounds, which heal poorly." 



It will be noticed that there is lacking tlu' usual ]ioriod of incuba- 

 tion that follows injection of bacterial toxins, and if it happens that 

 the venom has been injected directly into one of the veins, death may 



20a Trans. Koy. Soc, London (B), 1016 (208), 1. 



