VENOM HAEMOLYSIS AND VENOM AGGLUTINATION 187 



by venom, while not in the other set. This theory does not readily explain 

 the activating property of a serum which becomes inactive at 56 C., because 

 if it were lecithin which activates venom, heating would not suppress its activ- 

 ity, as it is found by Noguchi that the acquired activating property of a non- 

 activating serum through the addition of an adequate quantity of available 

 lecithin is not to be suppressed by a subsequent heating to that temperature. 

 Lecithin is also characterized by its prompt activation, no matter how it is 

 introduced into a serum. As to the quantities of lecithin existing in various 

 kinds of the activating as well as non-activating serums, there are no great 

 differences among them. The same difficulty is encountered in explaining 

 the susceptibility and non-susceptibility of the blood corpuscles of different 

 species of animals. They all contain lecithin in about the same quantities, 

 but venom can not attack them with equal readiness. In the case of dog's 

 corpuscles there is undoubtedly an indication that lecithin is concerned in 

 venom haemolysis. Again, in the case of serum of that animal the venom- 

 activating property of the fresh serum appears to be caused, at least in part, 

 by the presence of available lecithin. On the other hand, the thermolabile 

 activators contained in the serums of guinea-pig, horse, cat, pig, rabbit, pigeon, 

 hen, goose, and man are distinguished from lecithin by their slow activation. 

 Besides, activation of venom due to lecithin can not be prevented by the addi- 

 tion of calcium chloride, while activation caused by substances which are not 

 of the nature of lecithin is easily removed by this salt. Ether can not remove 

 lecithin from the mixture with serum; hence the activating property of the 

 serum which contains available lecithin remains undiminished after ethereal 

 extraction. 



On the other hand, the activators of the second group of serums go over 

 to ether and render the extracted serums no longer activating. Meanwhile 

 the substances extracted with ether can, when transferred to non-activating 

 serum, confer the activating property upon the latter in a marked way. 

 According to Noguchi the second group of activators consist mainly of non- 

 phosphorized fats, fatty acids, and their soluble salts; while in serum these 

 bodies are not hsemolytic, but become quite haemolytic when venom is intro- 

 duced. Their mode of activation therefore differs essentially from that 

 caused by combination of venom and lecithin. The activating property of 

 these bodies disappears when mixed with calcium chloride or heated to 56 C. 

 in the presence of serum components. On mixing non-activating serum with 

 oleic acid or soluble compounds of oleic acid, the former acquires activating 

 power very similar to that possessed by the fresh serums of the second group. 



In regard to the variable susceptibility of the washed corpuscles of various 

 kinds of bloods, Noguchi found an existing relation similar to that of activa- 

 bility of the different kinds of blood serums. The water-laked solution or the 

 stroma of the corpuscles of the non-susceptible kind does not contain venom 

 activators, while the reverse is true of the susceptible variety. Of the cor- 

 puscular activators there are again two groups one that of lecithin and the 

 non-phosphorized lipoids. The corpuscles of dog contain both sets, but 



