VENOM HAEMOLYSIS 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 10 per cent, cause instantaneous cessation of motility and 

 rapid agglutination without distinction of variety of cells. Within 5 to 30 

 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 — 



(1) 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 haemolysis 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 ioo° 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 



