THE MECHANISM OF THE ACTION OF AMBOCEPTORS. 213 



TABLE III. 



3. We know from the studies of v. Dungern 1 and Erhlich and 

 Sachs, 2 that yeast constitutes an excellent means of removing the 

 complements of a serum. If we prepared an inactive dog serum by 

 treatment with yeast instead of with heat, or if we allowed the com- 

 plementoids of a serum inactivated by heat to be absorbed by yeast, 

 it was found that a dog serum so treated was no longer capable of 

 causing this "blocking" phenomenon. Haemolysis occurred in like 

 manner whether we added the activating guinea-pig serum at once, 

 or first kept the blood-cell dog-serum mixture in the thermostat 

 for an hour. (See Table IV.) 



TABLE IV. 



* 6 cc. serum are shaken with 0.2 grams yeast. 



The complementoids had simply been removed by the yeast and the 

 isolated amboceptors reacted in normal fashion. 



1 See page 36 et seq 



2 See page 195 et seq. 



