NATURE OF HEMOLYSINS . 389 



the dissociated amboceptors found free of complement may be those that 

 did not have time to unite with complement, and there does not appear 

 to be any direct and positive experimental evidence to permit one to 

 decide between Ehrlich's and Bordet's views. 



While Ehrlich believes that the union between cell and amboceptor 

 is a chemical one and follows ordinary chemical laws, obeying the law 

 of multiple proportions, Bordet holds that the antibody acts as a mor- 

 dant and sensitizes the cell, comparing the process to the staining of 

 filter-paper when immersed in a dye, or to the use of mordants prepara- 

 tory to the staining of flagella of certain bacteria. For example, 0.4 

 c.c. of a hemolytic serum, if added at once, was found to dissolve 0.5 

 c.c. of corpuscles. If 0.2 c.c. of corpuscles were first added, and amounts 

 of 0.1 c.c. were added subsequently, no lysis took place after that of the 

 first portion added. Bordet cited this as an example of a physical pro- 

 cess of the nature of absorption, just as filter-paper when added at once 

 to a dye will be stained a uniform color, whereas if it be added a little at 

 a time, the first pieces inserted will be stained deeply, the subsequent 

 ones less and less so, until the dye is completely absorbed. Recent re- 

 searches on the colloidal theory of antibodies would indicate that the 

 hemolysins are governed by very complex chemicophysical laws, not as 

 yet fully understood, which regulate the action of colloids on one another 

 and are probably intimately concerned in the processes under discussion. 



As was stated in a previous chapter, Metchnikoff maintains that both 

 substances concerned in hemolysis are ferments, and that both are 

 adapted for intracellular digestion. He regards complement or his cy- 

 tase as a digestive ferment derived from leukocytes, and believes that it 

 is set free only when leukocytes are dissolved (phagolysis), either as 

 the result of the injection of a foreign substance or during the process of 

 coagulation. Amboceptor or his "fixateur" is likened to enterokinase, 

 and like it acts as an accessory ferment that unites the more potent fer- 

 ment (cytase) to the particle to be digested. He also regards it as being 

 derived from leukocytes, and considers that the amount formed depends 

 upon the degree of phagocytosis that occurs during the absorption of the 

 antigen. In the conception of immunity as being fundamentally a pro- 

 cess of nutrition, and in the belief of the existence of more than one com- 

 plement, the similarity between the views of Ehrlich and those of Metch- 

 nikoff is indeed striking. 



Analogy between Bacteriolysis and Hemolysis. Studies in hemol- 

 ysis aided greatly in a correct understanding of the mechanism of bac- 

 teriolysis. It became apparent that two substances were concerned in 



