NORMAL HEMOLYSINS 



391 



when they gain access to the blood. It is probable that, aside from 

 hemolysins, various normal and immune cytolysins play an important 

 part in the processes of immunity. 



While the normal hemolysins that may be found in the serums of 

 various animals have not as yet been fully worked out, the following 

 table, compiled by Sachs 1 is a resume of the work reported in the litera- 

 ture on the subject: 



TABLE 7. NATURAL HEMOLYSINS 



+ = Well-marked hemolysis. 



(+) = Questionable or feeble hemolysis. 



= Doubtful. 



= No hemolysis. 



Kolmer and Casselman 2 have titrated the natural hemolysins for the 

 corpuscles of various vertebrates in a large number of human serums. 

 Most interest centers about the occurrence of natural antisheep hemoly- 

 sin, because of the wide-spread use of an antisheep hemolytic system in 

 complement-fixation reactions, as, for example, the Wassermann syphilis 

 reaction. In over 80 per cent, of human serums there is present suf- 

 ficient natural amboceptor for sheep's cells to give well-marked or com- 

 plete hemolysis. Although this factor must be considered in using an 

 antisheep hemolytic system in complement-fixation reactions, yet with a 

 proper understanding of principles and the employment of a satisfac- 

 tory technic the danger of error is reduced to a minimum. In the fol- 

 lowing table the percentages of serums showing 100, 75, 25, and per 



1 Sachs, H. : Handbuch der pathogenen Mikroorganismen, Kolle and Wasser- 

 mann, 2. Auflage, 2, p. 799. 



2 Jour. Infect. Dis., 1915, 16, 441. 



