STUDIES ON ILEMOLYSIXS. 67 



all the cases observed by us. Still more convincing, however, is the 

 fact that neither the injection of a sheep with goat serum nor of a 

 goat with sheep serum results in the production of anticomplements. 

 All experiences indicate that the complements normally present in 

 the serum of a certain species of animal are not able to excite the 

 formation of anticomplements in such an animal's own body. Per- 

 haps this may be explained thus, that the relation between com- 

 plement and complementophile group is extremely slight (as was 

 shown by the binding experiments previously described by us) and that 

 therefore one of the conditions necessary for the thrusting off a per- 

 manent and firm union with the receptor is not in this case fulfilled. 

 We realize that we have been able here merely to point out some 

 of the principles applying to this subject. Their closer anatysis 

 encounters extraordinary difficulties in consequence of one of the 

 facts demonstrated by us, namely, the multiplicity of interbodies, 

 complements, and anticomplements. Thus far these difficulties have 

 been overcome in only a few favorable instances. 



HI. One of Bordet's Objections Controverted. 



Bordet, in his most recent work (loc. cit.) has described the follow- 

 ing interesting experiment, by means of which he believes to prove 

 that our views concerning the mechanism of haemolysis are incor- 

 rect. As hsmolysin, Bordet employed the serum of guinea-pigs after 

 these had been treated with rabbit blood. This then possessed a 

 high degree of solvent power for rabbit blood. If this haemolysin 

 is inactiviated by heating, it is possible to restore the haemolytic 

 action, as well by the addition of normal guinea-pig serum as by 

 that of normal rabbit serum. These two sera, therefore, contain 

 complements (alexins) which make the reactivation possible. Bordet 

 now sought to discover whether the "alexin" of rabbits is identical 

 with that of guinea-pigs. For this purpose he treated rabbits with 

 the serum of the immunized guinea-pigs and obtained an antiserum 

 which, while it contained a small amount of anti-immune body, 

 contained considerable anticomplement. He then determined that 

 this "antialexin" acted only against the "alexin" of the guinea- 

 pig and not at all against that of rabbits and some other animals. 

 At the same time a certain degree of action against the complement 

 of pigeon serum was noted, so that this antiserum was not absolutely 

 specific. From this Bordet concludes that his theory of sensitiza- 

 tion must be correct, namely, that the various alexins derived from 



