537 



On the Relationship betiveen Haemolysis and the Phagocytosis of 



Red Blood Cells. 

 By E. D. Keith, M.A., M.D. 



(Communicated by Leonard Hill, F.R.S. Eeceived February 15, — Read 



March 8, 1906.) 



The nature of the substance or property in normal as well as in immune 

 serum which induces phagocytosis has been of late a matter of considerable 

 discussion, and the chief point of controversy has been whether phagocytosis 

 is caused by some well-known immune substance, or whether it is brought 

 about by something which until recently had not been completely recognised as a 

 product of immunisation processes, e.g., the " opsonin " of Wright and Douglas. 



Whatever the nature of this substance may be, it seems established beyond 

 doubt that it acts on the bodies phagocytosed, the stimulin theory of 

 Metchnikoff and his school having given way to the theory supported 

 especially by Wright and other observers in this country, that the action is 

 on the bodies phagocytosed and not on the phagocytes, notwithstanding the 

 work of Lohlein(l), Leishman(2) and Besredka (3). 



Wright and Douglas (4 and 5) in their well-known work on this subject, 

 described this property of the serum as being due to a body which up to that 

 time had not been properly recognised. To this they gave the name 

 " opsonin," and by their ingenious experiments they rendered clear and 

 concrete what had been before but nebulous and ill-defined. 



They as well as Bulloch and Atkin (6) and Hektoen and Ruediger(7) 

 described this body as being thermolabile from the fact that it was to a large 

 extent destroyed by heating the serum to 55° C. to 65° C. Dean (8) 

 repeated this work, using a somewhat different technique, and having found 

 that in normal, but especially in immune sera, a certain amount was not 

 destroyed, decided to call it thermostable. As Wright (9) has since pointed 

 out, this is merely a matter of terms ; but from his as well as from Dean's 

 experiments it is clear that a very large amount of destruction takes place at 

 these temperatures. 



Dean at the same time put forward the view, shared chiefly by workers in 

 the Pasteur Institute in Paris, that the substance or property in the serum 

 described by Wright and Douglas was not new but had been well known 

 before, and Dean laid stress on the work of Savtchenko (10) on the 

 phagocytosis of red blood cells, pointing out that this property had been 

 attributed by Savtchenko to the " fixateur." 



As there seems to have crept into this question some doubt as to the 



