INTRODUCTORY Xlll 



in an ordinary sense has been conclusively proven by various experiments. 

 In fact, the majority of venom cytolysins are thermostabile in contradis- 

 tinction to the ordinary ferments and are of immense activity, while pepsin 

 or trypsin has but little cytolytic property upon the cells freshly taken out 

 of a living animal body. Thus, snake venom contains a set of toxic agents 

 entirely different from the physiological ferments of other glands. 



Do we, then, have a class of bodies whose mode of action is comparable 

 with that of the venom cytotoxins? To this question we answer in the 

 affirmative. The presence of cytolytic agents is by no means restricted to 

 snake venom, but the phenomena of cytolysis have -been constantly observed 

 with normal and especially immune serums. The investigations of Landois, 

 Buchner, Nuttall, Metchnikoff, Ehrlich, Morgenroth, Bail, Pettersson, Bordet, 

 Dungern, Moxter, Schattenfroh, Gruber, Sachs, Landsteiner, Flexner, 

 Noguchi, and others are sufficient to prove the wide occurrence of normal 

 and immune cytolysins in the blood serum. 



Through the classic works of Bordet, Erhlich, and Morgenroth the mechan- 

 ism of cytolysis occasioned by normal or immune serums has been shown to 

 be due to two constituents, which must cooperate to produce this effect. 

 Serum cytolysins are specific, and the specificity has been shown to be caused 

 by one of the constituents concerned in cytolysis and is capable of being 

 increased through artificial immunization. This is Ehrlich's amboceptor 

 and Bordet's substance sensibilisatrice. The second constituent taking part 

 in cytolysis is increased with difficulty by the immunization and is present 

 in all normal as well as immune serums. This is Ehrlich's complement and 

 Bordet's alexine. Its function is to inflict injury upon the cells already 

 treated with the specific ambocepter or substance sensibilisatrice. 



What, then, is the relation between the mechanism of serum cytolysis and 

 that of venom cytolysis? Many differences have been noted to exist in these 

 two sets of cytolysis. 



Flexner and Noguchi first demonstrated that venom cytolysis bears a 

 general resemblance to serum cytolysis, as the mechanism of solution of cells 

 is of a dual or complex nature, though this apparent parallelism has later been 

 found to be only partial. 



In venom cytolysis the complementary substances are sometimes inherent 

 to the cell itself, thus setting forth examples never met in the case of serum 

 cytolysis. The amboceptor or substance sensibilisatrice of snake venom is 

 much more thermostabile than that of serum, and many amboceptors in venom 

 retain their activity even after brief boiling. 



While a finer analysis of serum cytolysis has become a matter of extreme 

 difficulty and has added little to that which was brought out by the investiga- 

 tions of Ehrlich and Bordet several years ago, the nature of venom cytolysis 

 has been much more profitably studied in recent years. It may be con- 

 sidered safe to say that our knowledge concerning the venom cytolysis has 

 broken through the boundary of pure biological-physiological domain and is 

 now wandering in the biochemical realm. This advance has been the fruit 



