82 IMMUNE SERA 



curative power of many bactericidal sera might be 

 increased by the simultaneous injection of the sera 

 of certain normal animals in order thus to gain 

 an increased amount of complement; but we 

 shall soon see that this procedure, while of great 

 value in animal experiments, presents certain dif- 

 ficulties. 



Nature of the Immune Body Partial Immune 

 Bodies of Ehrlich Turning now to a closer study of 

 the nature of the immune body, we again find a dif- 

 ference of opinion. Whereas Bordet, MetchnikofI, 

 and Besredka assume each immune body to be a 

 single definite substance, Ehrlich and Morgenroth 

 as a result of their experiments hold to a plurality 

 of bodies. 



These authors say that each immune body 

 is built up of a number of partial-immune bodies, 

 a point to which we have already alluded. In 

 support of this view they offer the following ex- 

 periment. On immunizing a rabbit with ox blood, 

 they obtained a serum haemolytic not only for 

 ox blood but also for goat blood; on immunizing 

 a rabbit with goat blood they obtained a serum 

 haemolytic for goat blood and ox blood. 1 



The conditions present can be readily under- 

 stood by reference to Fig. 7, which represents 

 schematically three portions of the combining groups 



1 We have already called attention to these exceptions to the 

 rule of specific action. 



