20 The Cytotoxins of Blood Serum 



produced in animals by the injection of foreign blood corpuscles, appear to have 

 the same constitution as the normal haemolysins. 



Bordet (1895 1900) demonstrated the existence of the two bodies referred to 

 above by heating immune-serum to 55 C., or allowing the serum to stand for some 

 hours. Such serum was no longer cytolytic, but if he added fresh normal serum 

 to it, the normal serum of itself being inactive, the heated immune-serum regained 

 its haemolytic power, that is, it was reactivated. The immune-body persists 

 in stored sera, and withstands a temperature of 65 70 C. ; the thermolabile body 

 as we have seen is destroyed at 55 C. and is soon lost. According to Bordet 

 the immune-body or " matiere sensibilisatrice," as he terms it, becomes anchored 

 to a red blood cell or bacterium, rendering it highly susceptible to the influence 

 of the complement, to the action of which it was previously insusceptible. It is 

 the complement, or " alexine " as he terms it, which reactivates the immune-body. 

 Ehrlich and Morgenroth (1899) showed by most ingenious experiments that the 

 immune-body became fixed to the susceptible cells. 



By injecting complement, Bordet (v. 1900) produced anti-complement, which 

 prevented the action of the immune-body by neutralizing the complement, the 

 anti-complement not having any specific affinity for the immune-body. Bordet 

 and Oruber consider the complement or " alexine " identical in all cases, the 

 former and Gengou (1902, p. 738) found fresh dog serum added to fresh rabbit 

 corpuscles lost its bactericidal properties. Ehrlich and Morgenroth consider that 

 normal sera contain a multiplicity of complements. Metchnikoff (1901, p. 123) 

 points out that there is agreement as to the action of anti-complement upon 

 complement being direct. Bordet found that heating a mixture of these bodies 

 did not liberate the anti-complement, for the heated mixture does not regain its 

 anti-haemolytic power, as we might expect it to do if anti-complement were freed 

 by heating. Heating to 55, as we have seen, affects complement, but not anti- 

 complement. The conclusion is therefore justified, that complement and anti- 

 complement enter into chemical combination. Ehrlich and Morgenroth have found 

 moreover that anti-complement only prevents the action of complement, that it 

 exerts no action either on the immune-body or susceptible cell. 



Ehrlich (1900) and Morgenroth, by the method of "elective absorption," found 

 that a normally haemolytic serum contains a variety of intermediary bodies 

 (analogous to the immune-bodies in artificially haemolytic sera). They found 

 that a serum which had been treated with one species of corpuscles until it 

 ceased to act on these still had the power to haemolyse other species of corpuscles. 

 In the same way a multiplicity of complements appropriately adapted to the 

 various intermediary bodies have been found by them to exist in normal sera. 

 The union of cellular elements and the intermediary body is effected, according to 

 Ehrlich, by means of combining or haptophoric groups, common to both cell and 

 intermediary body, the complement being similarly linked to the intermediary 

 body. In other words, the intermediary body possesses two haptophoric groups, 

 the one (complementophilic) combining with the complement, the other with the 

 cell. The complement has also two haptophores, the one combining with the 

 intermediary body, the other possessing a fermentative action (zymotoxic, or toxo- 

 phoric group) which dissolves the cell. 



Flexner and Noguchi (1902) find that there are a multiplicity of intermediary 



