F)\2 STUDIES IX IMMUNITY. 



Bauer's objection is without foundation, and we have defined still 

 further the properties of that remarkable substance which we for- 

 merly called bovine colloid but which we now call conglutinin, the 

 intervention of which explains the peculiarities of this particular 

 instance of hemolysis. Without going into details as to this latter 

 work (which may he found in the Centralblatt fur Bakteriologie, 

 Vol. 49, second Heft), I may content myself with noting that, con- 

 trary to Ehrlich and Sachs' opinion, the bovine amboceptor is in no 

 way abnormal but agrees with the general law, which is that the 

 sensitizer does not act alone in absorbing alexin, but only the com- 

 plex, corpuscle-sensitizer. Streng has since continued the study of 

 bovine serum (see Centralblatt fur Bakteriologie, 1909). This 

 author has made some very interesting observations by employing 

 with the bovine serum, bacteria instead of corpuscles, which, in so 

 far as the theory of the action of serum is concerned, agree perfectly 

 with the experiments on corpuscles which we had performed. My 

 studies with Gay on the antagonistic power of serum, and Gengou's 

 numerous experiments on the phenomenon of adsorption, make 

 more evident the idea that fixation of. alexin is in reality an adsorp- 

 tion phenomenon. The striking analogies so far as the action of the 

 citrate of sodium is concerned, between the fixation of alexin or 

 other hemolysis on the one hand and the adsorption of certain 

 chemical precipitates on the other, are very suggestive and it 

 is unnecessary to insist on them further. Which of the argu- 

 ments that have been offered in favor of a complementophi- 

 lic group of the sensitizer still remain? In the first place the 

 existence of complementoids. On heating certain alexins very 

 carefully (for example toward 52 degrees), we find that their hemo- 

 lytic energy is much decreased; but alexins that have been altered 

 in this manner can still be absorbed by sensitized corpuscles. As 

 would be naturally expected, such corpuscles charged with com- 

 plementoids, that is to say an altered, or perhaps better, affected, 

 alexin are thenceforth incapable of fixing active alexin for the 

 simple reason that their capacity for alexin adsorption is not with- 

 out limits. These corpuscles, having been saturated with weakened 

 alexin, subsequently refuse the hemolytic alexin and consequently 

 remain intact. Gay has carefully explained this phenomenon in 

 his article on complementoids. What relation indeed have these 



