VENOM H#MOLYSIS AND VENOM AGGLUTINATION 171 
medium-sized granular cells have suffered disintegration, while lymphocytes 
show but slight and inconspicuous changes. Stronger solutions, varying 
from 0.2 per cent to ro per cent, cause instantaneous cessation of motility and 
rapid agglutination without distinction of variety of cells. Within 5 to 3o 
minutes thereafter dissolution sets in, affecting first the largest, then the 
medium-sized cells, and finally the small lymphocytes. 
There are variations in the activities of the several venoms and in the com- 
pleteness of solution of the cells. Rattlesnake venom is far less active than 
that of the Cobra. Thus in 2 per cent solutions cobra venom causes complete 
solution in 30 minutes, while that of the rattlesnake requires 2 hours to bring 
about the same result. (Plate 29.) 
The effects upon the washed leucocytes differ from those described in that 
venom solutions cause agglutination, but with the production of only very 
little lysis. 
The next question to decide was whether the hemolysins (erythrocytolysins) 
are identical with the leucocytolysins. The supernatant fluid free from the 
erythrocytolysins, as obtained by the usual absorption of copperhead venom 
with the washed corpuscles of rabbits, was allowed to act upon the leucocytes 
of the same animal. There was no agglutination, but a complete solution 
of the cells took place within 30 minutes. On the other hand, the parallel 
experiment in which venom solution was treated with washed leucocytes 
yielded a fluid still active for defibrinated blood. From these observations 
they concluded that — 
(rt) Venom contains principles which are agglutinating and dissolving for 
leucocytes. 
(2) The agglutinating principles may be identical for both white and red 
cells. 
(3) The dissolving principles for leucocytes are distinct from those for 
erythrocytes. : 
(4) In order that solution of venomized corpuscles shall occur a comple- 
ment-containing fluid is required. 
(5) The several varieties of white cells of rabbit blood show different 
susceptibilities to the action of venom. 
Calmette made a very important observation in regard to the mechanism 
of hemolysis caused by venom. He confirmed the finding of Flexner and 
Noguchi that venom requires a second substance or substances contained in 
blood serum in order to accomplish its dissolving action upon the corpuscles. 
Moreover, he found that the substance or substances of serum concerned in 
venom hemolysis differ from ordinary serum alexines in that they do not 
lose their activating property at 62°C. At this temperature there may be 
some diminution of this power, but if heated to 100° C. the venom-activating 
action of all serums becomes much more powerful than the unheated serums. 
Closely following the work of Flexner and Noguchi on one hand, and that 
of Calmette on the other, Preston Kyes, under the direction of Ehrlich, made 
