44 IMMUNE SERA. 



actually proposed such a procedure in the use of 

 bactericidal sera for therapeutic purposes.* 



Support for Ehrlich's View. Besides the above 

 experiments we possess others which support the 

 theory that the immune body is not a simple but 

 a compound substance, v. Dungern had already 

 shown that following the treatment of an animal 

 with ciliated epithelium from the trachea of an ox, 

 there were developed immune bodies which acted 

 not only on the ciliated epithelium but also on the 

 red cells of oxen. We must assume, therefore, that 

 the ciliated epithelium and the red cells of the ox 

 possess common receptors. Analogous to this is 

 the action of the immune body resulting from the 

 injection of spermatozoa, as was pointed out by 

 Metchnikoff and Moxter. 



We see, then, that the specific action of immune 

 bodies is not so limited as to apply only to the cells 

 used in the immunizing process, but extends to 

 other cells which have receptors in common with 

 these, t 



* Reasoning along similar lines, namely, that the human 

 complement must fit the immune body of the therapeutic 

 serum, Ehrlich has also proposed that these bactericidal 

 sera be derived from animals very closely related to man, 

 e.g., apes, etc. 



t The same holds good for the agglutinins and the pre- 

 cipitins still to be studied. In these the action extends 

 also to closely related cells and bacteria, or in the case of 

 the precipitins to closely related albumins, as these possess 

 a number of receptors which are common to them and to 

 the cells or substances used for immunizing. 



