BA CTERIOL YSINS A ND H&MOL YSINS 103 



Even more important than the question of a 

 decrease in complements, or an inhibition of their 

 action, is that of the possibility to artificially in- 

 crease them. A number of authors, among them 

 Nolf and Miiller, have answered this question in the 

 affirmative. They believe they have noticed such 

 an increase following the injection of an animal with 

 all sorts of substances, such as normal serum of 

 another animal, sterile bouillon, etc. v. Dungern, 

 Wassermann and others, have not been able to con- 

 vince themselves of the possibility of such a definite 

 increase. Wassermann tried to excite the increased 

 production of complement by injecting guinea pigs 

 for some time with antic omplement. This being 

 the opposite of the complement, he hoped to be 

 able by immunizing to excite an increase of the 

 complements, but in this he was unsuccessful. 



Despite all this, we must believe that the amount 

 of complement, as well as the amount of other active 

 substances of the blood, inter-bodies, agglutinins, 

 antitoxins, ferments, antiferments, etc., is subject 

 to great fluctuations even in the same individual, 

 a constant change going on within the organism. 

 Ehrlich, in particular, has pointed out these indi- 

 vidual and periodic variations and has insisted on 

 their importance. Very likely, under circumstances 

 of which we now know very little, these substances 

 are at certain times produced in greater amounts, 

 at other times in lesser; sometimes they may be 



