OPSONIC ACTION 539 



injection of leucocytes, spermatozoa, ciliated epithelium, liver cells, 

 nervous tissue, etc. The laws governing the production and properties 

 of these are identical, that is, each serum exhibits a specific property 

 towards the body used in its production i.e. dissolves leucocytes, im- 

 mobilises spermatozoa, etc. The specificity is, however, not so marked 

 as in the case of sera produced against red blood corpuscles ; thus 

 a serum produced against tissue cells is often haemolytic ; this is 

 probably due to various cells of the body having the same receptors. 

 Here again, when the anti-serum produces no destructive effect on the 

 corresponding cells, the presence of an immune-body may be demon- 

 strated by the increased amount of complement which is taken up 

 through its medium. It may also be mentioned that each anti-serum 

 usually exhibits toxic properties towards the animal whose cells bave 

 been used in the injections, e.g. a hrcmolytic serum may produce a fatal 

 result, with si^ns of extensive blood destruction, haemoglobinuria, etc., 

 h.4. it is hiernotoxic for the particular animal ; a serum prepared by in- 

 jection of liver cells has been found to produce on injection necrotic 

 changes in the liver in the species of animal whose liver cells were 

 used. These are mentioned as examples of a very large group of specific 

 activities. 



With regard to the sites of origin of immune-bodies our 

 information is still very deficient. Pfeiffer and Marx brought 

 forward evidence in the case of typhoid, and Wassermann in 

 the case of cholera, that the immune-bodies are chiefly formed 

 in the spleen, lymphatic glands, and bone-marrow. According 

 to certain workers of the French school, the chief source of anti- 

 substances acting on cells such as red blood corpuscles is the 

 large mononucleated leucocytes, whilst those acting on bacteria 

 are chiefly derived from the polymorpho-nuclear leucocytes (vide 

 p. 182). Another view is that immune-bodies are chiefly formed 

 by the large mononucleated leucocytes, whilst complements are 

 products of the polymorphs. That these cells are concerned in the 

 production of antagonistic and protective substances is almost 

 certain, though another possible source of wide extent, namely, 

 the endothelium of the vascular system, has been largely over- 

 looked. 'As yet, definite statements cannot be made on thisjpoint. 



(b) Opsonic Action. The presence of a substance in an 

 immune-serum which makes the corresponding organism sensi- 

 tive to phagocytosis was first demonstrated by Denys and Leclef 

 in 1895, in the case of an anti-streptococcal serum. They also 

 showed that the serum produced this effect by acting on the 

 organism, not on the leucocytes. It is, however, chiefly to the 

 researches of Wright and his co-workers that this subject has 

 come into special prominence. Wright and Douglas -in their 

 first paper showed that the phagocytosis of staphylococci by 

 leucocytes depended on a body in the normal serum which 

 became fixed to the cocci and made them a prey to the 



