298 COLLECTED STUDIES IX IMMUNITY. 



because of this thermostability, especially since we know that 

 Ehrlich and Morgenroth l have described a partial complement 

 in goat serum which was much more thermostable. According to 

 some "unpublished studies by Shiga such thermostable complements 

 seem to take part in the bacteriolysis of anthrax bacilli by rabbit serum. 

 The active group of coagulins and agglutinins, which, according to 

 Ehrlich, is analogous to the zymotoxic group of complements, is still 

 more thermostable, 2 for inactivation takes place only between 70 and 

 75 C. 



From all this it follows that we must assume the blood-cells which 

 are sensitive to the above poison, to be supplied both with receptors 

 and complements. Through the intervention of the amboceptors 

 added, the discoplasma enters into that intimate combination with 

 the complement which is necessary in order that the latter may act. 



We should like to add a few explanatory remarks to these state- 

 ments, and shall begin with the conception of complements as endocom- 

 plements. One could, for example, assume that the endocomple- 

 ments are derived not from blood-cells themselves but from the serum 

 still adherent to these. However, we believe that the repeated wash- 

 ing and centrifuging has completely freed the red blood-cells from 

 serum. Guinea-pig blood-cells were washed and centrifuged eight 

 times, yet even after that the dissolved blood-cells manifested the 

 complement action. This excludes the possibility of the action being 

 clue to adherent serum. Another thing which speaks against this is 

 the fact, now and then observed by us (mostly, to be sure, merely 

 indicated) that the last decantations activated more strongly even 

 than the first. If the washing removed adherent serum constituents, 

 the first washings should contain more than the later ones. As 

 a matter of fact just the reverse was found to be the case; which 

 indicates that we are dealing with an extraction phenomenon. 



In one case we even succeeded in entirely removing the endo- 

 complement by means of salt solution. This was a suspension 

 (5% in 0.85% salt solution) of rabbit blood, which is dissolved 

 by cobra poison. This suspension was kept in a refrigerator for 

 twenty-four hours and then centrifuged, when it was found that 

 the sedimented blood-cells suspended in fresh salt solution were no 



1 See pages 11 et seq. 



2 See Bail, Archiv fiir Hygiene, Vol. XLII, 1902; also Eisenberg and Volk, 

 Zeitschr. f. Hygiene, Vol. XXXIV, 1902. 



