132 PROPERTIES OF ILEMOLYTIC SERA 



hsemolytie serum, and the resulting red fluid is passed 

 through a porcelain filter, the filtrate is found to be free 

 from receptors. (The physical means by which they are 

 retained is an open question : it does not follow that the 

 receptors are attached to particles which are too large to 

 pass through.) When the corpuscles are laked with water 

 and the red fluid is filtered, a small fraction of receptors 

 pass through, especially after filtration has been continued 

 for some time. The difference in these two results is pro- 

 bably due to the more disruptive action of the water on 

 the substance of the corpuscles. 



