236 VENOMOUS SNAKES AND THE PHENOMENA OF THEIR VENOMS 



which every trace of haemolysin had been removed by Kyes's method for the 

 isolation of venom lecithid. It was found that this modified venom solution 

 was highly toxic, especially upon the nervous system. In various pharma- 

 cological tests it was identical with the raw venom as far as its lethal prop- 

 erties are concerned. Thus it was chiefly the neurotoxin which was contained 

 in that haemolysin-free solution of cobra venom which was hence called the 

 neurotoxin. Jacoby 1 found, however, a very important difference between 

 the neurotoxin and the raw cobra venom, when he attempted to neutralize 

 the former with Calmette's antivenin. The antivenin was protective against 

 the raw venom, but not at all against the isolated neurotoxin. This incapa- 

 bility of Calmette's antivenin to neutralize the neurotoxin was ascribed to a 

 possible modification of the molecule during the isolation from haemolysin, 

 and a parallel was drawn between this and that observed by Kyes with the 

 isolated cobra lecithid. On the other hand, Jacoby succeeded in producing 

 immunity in rabbits against the isolated neurotoxin and found that the 

 serum of the immunized animals had neutralizing properties for the neuro- 

 toxin as well as the raw cobra venom. This singular phenomenon was also 

 observed by Kyes with his haemolytic lecithid. 



SPECIFICITY OF ANTIVENINS DUE TO DIFFERENCES IN INDIVIDUAL 

 CYTOTROPIC TOXINS OF VENOMS OF DIFFERENT SPECIES. 



In the past few years the question of venom immunity has become rather 

 far-reaching. Since the establishment of the facts that the action of anti- 

 venin is specific and that an antivenin may be incapable of neutralizing one 

 set of toxins, while the other set may be completely counteracted, attention 

 has been given to whether or not one particular toxin is common to the venoms 

 of different species. We have already seen that all venoms of Elapinae and 

 Hydrophiinae contain one type toxin destructive to the nervous system. Is 

 the neurotoxin contained in the venom of Naja tripudians identical with that 

 present in Bungarus or Enhydrina? The venoms of vipers and of certain 

 Australian Colubrinas are known to contain fibrin ferment, but is the fibrin 

 ferment of the venom of Daboia identical with that of Echis or Pseudechis or 

 Notechis ? The crotaline venoms contain a considerable amount of haemor- 

 rhagin, but is that principle contained in Crotalus identical with that of An- 

 cistrodon? The same inquiry arises also as to the haemolysin and other 

 cytotoxins contained in different kinds of venoms. 



This question of the specificity of various individual type toxins is of the 

 utmost importance both from practical and theoretical standpoints. To 

 those familiar with the almost fabulous discriminative immunity reactions 

 of living organisms to a countless variety of toxins and albuminoid bodies, 

 it may not appear extraordinary that the neurotoxins, haemolysins, fibrin 

 ferments, haemorrhagins, and still other cytotoxins of the venom of one species 

 should differ from the similar principles of other species of snakes. Never- 



1 Jacoby. Ueber die Wirkung des Kobragiftes auf das Nervensystem. Beitr. z. wissensch. Medicin 

 und Chemie. Festschrift zu Ehren des 60. Geburtstages von Ernst Salowski. Berlin, 1904, 200. 



