196 VENOMOUS SNAKES AND THE PHENOMENA OF THEIK VENOMS 



cury. As has been shown by Madsen and Walbum, acids in excess produce 

 non-haemolyzability of the corpuscles, whereas their weaker concentration 

 causes regular dissolution of the cells. 



Kyes and Sachs explain this phenomenon by assuming that an excess of 

 venom amboceptors produces "side-tracking" of lecithin and renders the 

 latter unable to attack the venomized corpuscles. In other words, the haemo- 

 lytic amboceptors of the venom are responsible for this phenomenon when 

 used in great excess. They did not, however, produce the evidence that the 

 venom from which all coagulable constituents have been eliminated by a 

 brief boiling, which is insufficient to diminish its haemolytic power, is still 

 capable of producing this protective phenomenon. 



Noguchi analyzed this phenomenon in quite a different manner and reached 

 an entirely different conclusion. He treated the washed corpuscles of horse 

 with varying strengths of different venoms, ranging from a superhsemolytic 

 (or non-hsemolyzable) dose to an optimum haemolytic dose (this latter con- 

 centration is only haemolytic in the presence of suitable venom activators). 

 When venom is present in more than 5 per cent concentration the haemolysis 

 of the defibrinated blood of horse is retarded for nearly 12 hours at 20 C, 

 causing no lysis within the first 6 hours. But as long as there is a trace of 

 serum constituents in the mixture complete dissolution can not be prevented 

 by any practicable concentration of venom. An equal mixture of the defibrin- 

 ated blood and 2.5 per cent cobra-venom solution will undergo haemolysis in 

 1 or 2 hours. 



It has already been stated that the thoroughly washed corpuscles of horse 

 are not haemolyzed by venom, no matter what the degree of concentration. 



If cobra venom in strengths above 4 per cent be mixed with a corpuscular 

 suspension of 5 per cent, no change may take place in the mixture in many 

 weeks; while with a quantity of venom as small as 0.1 per cent the cells will 

 disintegrate rather more quickly than in control tubes which are not entirely 

 sterile. 



Corpuscles which had been brought into contact with the stronger solutions 

 of venom were tested for resistance to salt solutions of varying toxicity. These 

 tests disclosed the unexpected fact that corpuscles thus highly venomized, 

 and in the presence of an excess of venom, are not haemolyzable even by 

 water. At the same time their susceptibility to heat is changed. It has 

 been found that the control tubes of blood corpuscles alone are haemolyzed 

 completely in from 175 to 180 minutes when kept at the constant temperature 

 of 53 C. In the presence of venom of a concentration not exceeding 1 per 

 cent, complete haemolysis will take place at this temperature in from 5 to 15 

 minutes; with a concentration of venom as low as 0.0 1 per cent 30 minutes 

 will be required; with a concentration of 10 per cent there is no perceptible 

 change in the corpuscles for the first 20 minutes, after which laking com- 

 mences. This last laking is not, however, typical. A bright haemoglobin 

 color does not appear in the fluid, but the cells undergo disintegration, the 

 color of the mixture becomes coffee-like, and in about an hour a turbid pre- 



