S. C. BROOKS 



63 



haiistion of the supply of cells. (In the latter case we may conceive 

 that the fundamental reaction is still proceeding at a relatively rapid 

 rate even in the most resistant cells at the time when they succumb.) 

 Enumeration of the red blood cells visible in a given volume of sus- 

 pension at various stages of hemolysis shows that the amount of 

 hemoglobin hberated is very nearly proportional to the number of 

 cells which have lost their pigment (Table I and Fig. 1). Handovsky^ 

 finds a similar parallelism between the disappearance of cells and the 

 liberation of hemoglobin when erythrocytes are partially hemolyzed 

 by saponin in low concentrations. 



100% 



/^iTL. 



Fig. 1. The time curve of hemolysis produced by ultra-violet radiation (soHd 

 circles), and by various dilutions of complement acting on specifically sensitized 

 cells (open circles) ; the degree of hemolysis was colorimetrically determined. 

 The crosses represent the degree of hemolysis as determined by cell counts during 

 the course of the process represented by the adjoining curve. The ordinates 

 represent the amount of hemolysis in per cent of completion, and the abscissae, 

 time in minutes. 



The course of hemolysis depends therefore on the relative number of 

 red blood cells having in different degrees the power to resist the ac- 

 tion of the lytic agent. For since the amount of hemoglobin liberated 

 is always proportional to the number of erythrocytes which have dis- 

 appeared we must regard the observed course of hemolysis as the 

 summation of the laking of individual cells at varying times after they 

 are subjected to the condition leading to hemolysis. A few relatively 



^Handovsky, H., Arch. cxp. Path. u. Pharmakol., 1912, Ixix, 412. 



