COBRA-LECITHID. 275 



only in a very loose way, whereas in more resistant 

 cells the union is of a firmer nature. 



The relationship between cobra amboceptors and 

 lecithin seems to be a very definite one, for Kyes 

 was able to obtain a union of the two without the 

 intervention of erythrocytes. The resulting sub- 

 stance, the cobra-lecithid of Kyes, is a completed 

 toxin and needs no further activation. We have 

 yet to learn of the true nature of this new com- 

 pound, the discovery of which seemed to augur a 

 more intimate chemical knowledge of the sub- 

 stances which are concerned in immunity. 



According to Bang lecithin itself has no activat- 

 ing power for snake venoms. He attributes the 

 hemolytic action of the product of the action of 

 lecithin on venom according to the Kyes technic 

 as due to pre-existant impurities in the lecithin. 

 That hemolytic substances exist in unpurified 

 lecithin there is no doubt. The lecithin used by 

 Kyes in his experiments, however, was prepared 

 with great precaution to avoid the presence of 

 such substances. 



v. Dungern and Coca attribute the action of 

 lecithin or venom to a splitting off of hemolytic 

 products from the lecithin and fail to obtain an 

 "antilecithid" by immunization. They also point 

 to a similarity between Kyes elementary analysis 

 of the lecithid and that of lecithin and confirm his 

 analysis. Their view is supported by Manwaring. 



Kyes, however, had pointed out the fact that 

 elementary analysis is, as a general rule, insuffi- 

 cient to determine differences in substances con- 

 cerned in immune reactions and by a determina- 

 tion of molecular weights shows that cobra lecithid 



