296 



COLLECTED STUDIES IN IMMUNITY. 



of very strong snake poison, they will not be dissolved. The mixture 

 is now centrifuged and the sediment washed with salt solution. No 

 solution takes place; as soon as fitting complement is added, however, 

 solution ensues very promptly. This shows that by the treatment with 

 the poison the complement contained in the red blood-cells has been 

 abstracted. The following diagram will make this clear. 



I. Blood-cell with receptor r and endocomplement e. 



II. Blood-cell after treatment with a large amount of cobra poison. The 

 cobra amboceptor c has been anchored by the blood-cell receptor. The 

 endocomplement has been abstracted from the cells by the large excess of 

 free amboceptor. 



III. Blood-cell of stage II after the addition of complement or endocomplement e. 

 The added endocomplement has combined with the cobra amboceptor c 

 and can now effect solution. 



The following experiment may serve as an illustration. (See 

 Table III.) 



TABLE III. 



The correctness of this view can readily be shown in another 

 way If the blood-cells actually do contain an endocomplement, it 

 must be possible to demonstrate this by dissolving the blood-cells in 

 water and finding that these dissolved cells are capable of acting as 

 complement to cobra poison for such blood-cells as are incapable of 

 being dissolved by cobra poison alone. 



