SUBSTANCES WHICH ACTIVATE COBRA VENOM. 



461 



many cases owing to the occurrence of a marked inhibition of haemolysis 

 due to the presence of an excessive amount of cobra venom. 



Kyes (1. c ) has already discussed in detail the fact that in hae- 

 molysis with cobra venom alone a phenomenon can occur which is 

 analogous to the deflection of complement described by M. Neisser 

 and Wechsberg. 1 In rabbit blood we have observed extensive indi- 

 vidual differences so far as this deflecting phenomenon is concerned. 

 We have often found animals whose blood-cells remained undissolved 

 in the presence of even a very slight excess of cobra venom, so that 

 it was necessary to have just the right amount of venom in order 

 to effect hamolysis. Table XVI shows several examples of this. 



TABLE XVI. 



The marked deflection which is observed in the blood of rabbits I, 

 II, III is evidently caused by a relatively slight amount of activating 

 substances present in and at the disposal of the red blood-cells. On 

 the other hand the different behavior of other bloods, as in rabbit IV, 

 shows how the amount of free lecithin contained in the blood-cells 

 can vary from case to case. It might pay to examine the blood 

 of different rabbits for this purpose. 



See page 120. 



