ON HJEMOLYTIC RECEPTORS 131 



the higher temperature, while in the fluid from (b) no per- 

 ceptible amount of immune-body is present. This is an 

 additional illustration of the reversibility of the combination, 

 receptor -j- immune-body. 



GENERAL SUMMARY 



1. By the method employed, which affords a compara- 

 tively delicate test for the presence of receptors, it has 

 been shown that the haemolytic receptors of the red cor- 

 puscles are comparatively stable molecules. So far as is 

 shown by their combining affinities, they are not destroyed 

 when the corpuscles are laked by water or by ether ; the 

 fluid resulting from laking having the power of taking up as 

 much complement through the medium of the immune-body 

 as the original suspension had. It is almost unnecessary 

 to point out that this result brings into special promi- 

 nence the fact that in the case of such haemolytic sera 

 we have a chemical interaction between three sets of mole- 

 cules receptor, immune-body, and complement and that 

 this interaction can be demonstrated as readily when the 

 corpuscles have been disintegrated by certain laking agents 

 as -when they are in the intact condition. The receptors 

 also show considerable stability when exposed to higher 

 temperatures ; while a small proportion are destroyed at 

 65 C., a considerable number resist exposure to 100 C. 

 for an hour. 



2. When corpuscles are lysed with water or a single dose 

 of haamolytic serum, it can be shown by centrifugalization 

 that the greater number of receptors remain attached to 

 the stromata and become sedimented with them ; the 

 upper clear fluid also, however, contains a considerable 

 number, even although no stromata can be seen on micro- 

 scopic examination. 



3. When red corpuscles are lysed with a single dose of 



K2 



