478 COLLECTED STUDIES IN IMMUNITY. 



Bothrops poison is ten times weaker, and that of Trimeresurus anama- 

 lensis twenty-five times. This observation made the formation of 

 a lecithid seem probable. As a matter of fact it was easy, by means 

 of the method above described, to prepare a solid lecithid which 

 contained the entire haemolytic power of the poisons. 1 Hence we 

 believe that in general all haemolytic snake venoms are of the am- 

 boceptor type and possess a lecithinophile group, the occupation of 

 which by lecithin gives rise to the haemolytic action. In fact it 

 seems as though in the last analysis the factor which determines the 

 type of the haemolytic action of snake venom was principally this 

 lecithinophile group. 



A fact which goes to support this view is the observation that 

 several of the poisons examined by us probably differ in their hapto 

 phore group, which unites with the receptor of the blood-cells. Thus 

 Lamb 2 has shown that the Daboia amboceptor, unlike the cobra 

 amboceptor, is not inhibited in its action by Calmette's serum. The 

 same is true for Bothrops, Crotalus, and Trimeresurus Riukiuanus, 

 whereas the poisons of Bungarus and Naja haye are similar to the 

 cobra venom so far as their behavior toward the serum is concerned. 



It is quite possible, therefore, that the differences in the various 

 types of poison are only differences in the haptophore group, while 

 the characteristic lecithinophile group is identical in all cases. 



It was important to see whether in animals other than snakes 

 poisons are present which are capable of forming lecithids. We 

 therefore next studied the poison of the scorpion, choosing this 

 because Calmette 3 had already shown that the acute fatal action 

 of scorpion poison could be inhibited by the snake-venom serum, 

 a fact indicating a certain analogy between the toxic components 

 of scorpion poison and snake venom. 4 We were able to determine 

 that the scorpion poison by itself exerts only a slight haemolytic 

 action on guinea-pig blood-cells, leaving other species of blood-cells 

 unaffected. On the addition of lecithin, however, it exerts con- 



1 In conformity with its weaker action Bothrops poison yields only a tenth 

 the lecithid obtained from the other poisons, and the poison of Trimeresurus 

 anamalensis only one twenty-fifth. 



2 Lamb, Scientific Memoirs, Medical and Sanitary Depts., Govt. of India, 

 1903, No. 3. 



3 Calmette, Ann. de ITnstit. Pasteur, 1895, No. 4. 



4 For this scorpion poison we are much indebted to Prof. Treub, Director of 

 the Botanical Garden in Buitenzorg. 



