I 



1906.] Hcemolysis and the Phagocytosis of Red Blood Cells. 545 



This first part of the experiment corroborates the result of the experiment 

 mentioned immediately above. 



In series C and D (the proportions of the serum in the mixtures 

 corresponding to 1 in 220, 1 in 450, 1 in 730 and 1 in 1100 approximately), 

 one series being heated and the other unheated, and both being uncom- 

 plemented, it was found that there was no sign of haemolysis when these 

 were compared with the controls, which were the same as in the previous 

 experiment. The tubes of these two series were thoroughly shaken and 

 centrifugalised. The supernatant fluid was pipetted off and the deposits 

 washed thrice with 0'85 saline solution. To each deposit an equal quantity 

 of normal saline was added. They were then well shaken and drawn up and 

 down rapidly in capillary pipettes in order to produce a uniform suspension. 

 Equal parts of each deposit and washed human leucocytes were mixed in 

 capillary pipettes and placed 15 minutes at 37° C, films being then made 

 and stained in the usual manner. 



Result. — In no case was any phagocytosis observed, although in dilutions 

 of 1 in 10 similarly treated, 93 per cent, of the polymorphonuclear leuco- 

 cytes contained erythrocytes, which shows that such deposits can be 

 phagocytosed, provided that the substance which induces phagocytosis is 

 present in sufficient amount. Although in series C and D no phagocytosis 

 occurred, yet in dilutions of 1 in 220 haemolysis was almost complete in the 

 complemented series, which shows that there must have been a large amount 

 of hseinolytic amboceptor present, and that notwithstanding this large 

 amount of amboceptor and an exposure during two hours of the red blood 

 cells to it, no phagocytosis was observed. 



This second part of the experiment then shows that in an immune clilvied 

 hemolytic serum a considerable amount of hemolytic amboceptor may be 

 present without rendering the red cells capable of being phagocytosed. 



This is supported by observations on non-immune hemolytic sera. In the 

 case of a guinea-pig's serum which was found in dilutions of 1 in 6 to 

 produce slight haemolysis of 2 c.c. of a 5-per-eent. suspension of the washed 

 blood corpuscles of a rabbit, it was observed, that in phagocytic tests 

 performed with the unheated serum, the human leucocytes used as the 

 phagocytic agents contained in many cases blood shadows. These were 

 found in 40 to 50 per cent, of the leucocytes in tests performed in the 

 manner described in the former part of this paper. When, however, heated 

 serum is employed no blood shadows are to be seen in the leucocytes nor is 

 there any sign of phagocytosis. 



In the case of the serum of an eel it was found that - 01 c.c. produced 

 after two hours at 37° C. marked haemolysis of 2 c.c. of a 10-per-cent. 



