<54 COLLECTED STUDIES IN IMMUNITY. 



(certains rapports convenables). It would be difficult to express 

 these relations in a form chemically comprehensible. 



Based on the conception of strictly specific relations, such as 

 follows from our theory, the study of these complements acquires a 

 high practical value. Donitz 1 has already called attention to the 

 great importance for the therapy of infectious diseases of finding 

 sources yielding sufficient complement, von Dungern 2 has further- 

 more shown that body cells are able to bind certain complements and 

 that therefore a completed bacteriolysin derived from a certain 

 animal species can, when it is injected into another organism, entirely 

 lose its complement and so become inactive. 



In the Croonian lecture (March 22, 1900), Ehrlich pointed out 

 that the bacteriolysins and hsemolysins (interbody + complement) 

 possess three haptophore groups, of which two are on the interbody 

 and one on the complement. It is conceivable that for each of 

 these groups there is a corresponding antigroup which binds the 

 haptophore concerned and so inhibits the action of the lysin. For 

 each lysin therefore three antibodies are possible, the action of any 

 one of which is able to put the lysin out of action. At that time 

 Ehrlich called particular attention to the important role of one of 

 these antibodies, namely, the one which fits into the haptophore 

 group of the complement and so prevents this from combining with 

 the interbody (immune body). He stated further that together 

 with Morgenroth he had succeeded in the experimental production 

 of such anticomplements by means of immunization. 3 



Our observations in this direction were made on the serum of 

 a goat which for a long time had been injected with large amounts 

 of horse serum. Horse serum was used because our extended ob- 

 servations had shown that this constitutes a particularly rich source 

 of most varied complements, and because it was therefore to be 

 expected that a plentiful amount of anticomplements would be 

 obtained. This expectation was fully realized, and we have come 

 to know a large number of interbodies of different origin which can 

 be reactivated by the complements for different varieties of blood 

 contained in horse serum. As an example the following combina- 

 tions may be mentioned.: Rabbit blood inactive dog serum; guinea- 



1 Donitz, Klinisches Jahrbuch, Vol. 7, 1899. 



2 See page 36. 



3 In the meantime Bordet (loc. cit.) independently has also produced anti- 

 complements by means of immunization. 



