VENOM HZMOLYSIS 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 hemolysis. 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 hemolytic, but become quite hemolytic 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 
