3 IMMUNE SERA. 



the observations of other authors confirm this opin- 

 ion. Agglutinated bacteria are capable of living 

 and of reproduction, and agglutinated red blood- 

 cells are no more fragile or easier to destroy than 

 normal, not agglutinated cells. Neither can any- 

 thing be discovered microscopically which would 

 indicate any injury to their structure. 



One thing is certain: that the agglutinins are in 

 no way related to the lysins found in serum, 

 and so, of course, are not identical with these. The 

 simultaneous occurrence in a serum of immune 

 bodies, inter-bodies, complements, and agglutinins 

 is an entirely independent phenomenon which is no 

 way regular. There are sera which dissolve certain 

 cells without agglutinating them, and others which 

 agglutinate cells without dissolving them. 



Difference between a Normal and a Specific Immune 

 Serum. Practical Application. Returning now to 

 the question of the difference between a specific 

 immune serum and a normal one, we find this to be 

 as follows: Normal serum contains a great variety 

 of inter-bodies, in very small amounts, and a consid- 

 erable amount of complements. In immune serum, 

 on the other hand, the amount of a specific inter- 

 body, the one which fits the haptophore group of a 

 certain cell, is enormously increased. This spe- 

 cifically increased inter-body, it will be remembered, 

 is called the immune body. The complement, as 

 shown by v. Dungern, Bordet, Ehrlich and Morgen- 

 roth, and myself, is in no way increased by the im- 



