482 IMMUNITY 



substances. These facts abundantly show how close an analogy 

 obtains between anti-bacterial and hsemolytic sera, and how 

 important a bearing hsemolytic studies have on the questions of 

 immunity in general. 



In addition to hsemolytic sera, anti-sera have been obtained 

 by the injection of leucocytes, spermatozoa, ciliated epithelium, 

 liver cells, nervous tissue, etc. The laws governing the pro- 

 duction and properties of these are identical, that is, each serum 

 exhibits a specific property towards the body used in its produc- 

 tion i.e. dissolves leucocytes, immobilises spermatozoa, etc. 

 The specificity is, however, not so marked as in the case of 

 sera produced against red blood corpuscles ; thus a serum pro- 

 duced 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 demonstrated 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 have been used in the injections, e.g. a 

 hsemolytic serum may produce a fatal result, with signs of 

 extensive blood destruction, hsemoglobinuria, etc., i.e. it is 

 hsemotoxic for the particular animal ; a serum prepared by 

 injection 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. 495). 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, 

 viz. the endothelium of the vascular system, has been largely 

 overlooked. As yet, definite statements cannot be made on this 

 point. 



