THEORIES OF IMMUNITY. 



blood stream only after some destructive action 

 on the cells, and furthermore that it may take 

 part in the completion of the immunity occurring 

 in many infectious processes as well as in many 

 cell reactions. On the other hand, Ehrlich 

 argues forcibly for the multiplicity of comple- 

 ment, claiming that this substance is multiple 

 and specific for each reaction, as is the case with 

 immune body. 



Walker (Journal of Hygiene, 1902, Vol. II., 

 p. 85) furnishes the specific evidence of the 

 identical nature of complement coming from dif- 

 ferent animals as follows: .he found that the 

 anti-typhoid serum from a horse that has been 

 inactivated by the application of heat — thus de- 

 stroying its complement — may be reactivated 

 by the addition of serum from the rabbit, ox, and 

 the pig (thus adding fresh complement). This 

 may be represented graphically as follows : 



Anti-typhoid serum contains 



Complement, molecule =H+L+X 

 Immune body, molecule=H+iZ4-X 



Other constituents, molecule=P(roteids)+S 



(alts)+X. 



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