662 



COLLECTED STUDIES IX IMMUNITY. 



To 1 cc. 5% ox blood are added 0.0015 cc. rabbit amboceptor, and the 

 mixtures kept at 37 for one hour. Each tube receives decreasing amounts 

 df uiitiserum. those in series A directly, and those in series B, to the blood- 

 cells sepanited by centrifuge and freed from the fluid medium in which they 

 h:id brt-M suspended. The two series therefore contained, in addition to the 

 antiserum: 



Srr/c.s .1. Blood-cells laden with amboceptor, plus free normal ambocep- 

 tors, plus precipitable substance. 



'.'. Only blood-cells laden with amboceptor. 



Botli seta of tubes are kept at 37 for two hours, then in the refrigerator 

 over niht, and centrifuged the next morning. The sediments are suspended 

 in physiological salt solution to which, for each tube, H solvent doses of 

 guinea-pig serum have been added (0.03 cc.). The degree of hsemolysis is 

 noted at the end of t and 2 hours. See Table VI. 



TABLE VI. 



A number <>f points are brought out by this table. In series B we observe 



the antiamboeeptor has exerted a distinct influence on the antiambo- 



rej,t,,r' anchored by the cells and freed from other serum constituents. 



camming il..- tubes at the end of half an hour we see that hsemolysis has 



i-i-n markedly inhibited. Subsequently, however, this inhibition gradually dis- 



bal MI tin- end of two hours what little antihamolytic action is 



insignificant when compared to the antiamboceptor action at 



' -'"l "' I'-'ll' an hour. This result agrees very well with the assumption that 



complement IB able, after a time, to dislodge the antiamboceptor. On 



Comparing the reaulta in series B with those in series A, we note that the 



1 Misprint for amboceptor (?) [Editor.] 



