4 QUATERCENTENARY STUDIES IN PATHOLOGY 



showing that the ultimate agents concerned in phagocytosis — the 

 neutrophile leucocytes— may vary greatly in their phagocytic power, 

 quite apart from changes in the opsonic content of the serum. But 

 these results, though interesting, do not affect the main proposition that, 

 under conditions which do not primarily involve the haemopoietic system, 

 the serum is the main variant. 



If then the phagocytic power of the neutrophile leucocyte remains 

 approximately constant both in normal and pathological conditions, two 

 questions arise which we shall endeavour to answer in this paper. 



1. Will the presence of a leucocytosis in the circulating blood have 



any effect on the opsonic content of the serum, either in the 

 way of raising or lowering it ? And, in this connection, is 

 there any evidence pointing to a probable origin of opsonic 

 substances from products of degenerated leucocytes ? 



2. If the leucocyte, normally, has a constant phagocytic property, does 



this relationship hold good in the stage of hyperleucocytosis ? 



Both of these questions are obviously of great interest from the point 

 of view of vaccine-therapy the immediate effect of which, at least, is to 

 cause some disturbance of the blood picture. For the production of 

 experimental leucocytosis, we decided that it was of great importance to 

 choose fairly simple chemical bodies such as sodium cinnamate, tallianine, 

 etc., and to avoid bodies of more complex chemical constitution such as 

 bacterial proteins and sterile culture emulsions, which, though causing on 

 inoculation definite leucocytic changes (Romer(3), Schlesinger (4), Holmes 

 (5), and others), have been shown by Wright and Douglas to raise the 

 opsonic content of the serum. 



This method of attacking the problem by inoculating leucocytosis- 

 producing substances has been much employed and elaborated since 

 Buchner's (^) first application of it to the problem of the nature and 

 origin of the alexine of normal serum. 



The work of Nuttall (7), Nissen (8) and Buchner, which went to show 

 the presence of a thermolabile bactericidal body in cell-free serum, 

 was followed by numerous researches, notably of Hankin (9), Denys (^o), 

 Wasserman (^i), Buchner (/oc. czt.), Schuster (^^), Schattenfroh (^^'), etc., 

 which had for their object the demonstration of bactericidal substances 

 elaborated by the leucocytes themselves. 



(324) 



