ON H^MOLYTIC RECEPTORS 129 



The conclusions which can be drawn from these observa- 

 tions are, that a fluid containing much fewer receptors can be 

 obtained by filtration than is possible by means of centri- 

 fugalization the filtrate in the earlier stages of filtration 

 being practically free from receptors. On the other hand, 

 it is shown that an appreciable amount of receptors can pass 

 the filter when the process of filtration has continued some 

 time, this amount being greater in the case of the Berkefeld 

 than of the Chamberland filter. 



(6) Laking with hasmolytic serum. We add multiple doses of 

 immune-body, allow time for combination, then wash and centri- 

 fugalize the corpuscles to remove the small amount of uncombined 

 immune-body, and lyse with a minimum dose of complement. The 

 resulting fluid, which takes up further complement according to the 

 amount of immune-body present, is then filtered as before. 1 



The result obtained both with a Berkefeld and a Chamber- 

 land filter is that no receptors are present in the filtrate ; 

 that is, to put the matter in another form, the filtrate has 

 no power of taking up complement when immune-body is 

 added to it. The problem as to the condition in which the 

 retained receptors are, is the same as in the previous case. 

 The difference between the two methods of lysis would 

 appear to be that the more disruptive action of water has 

 the effect of enabling a small proportion of receptors to 

 pass the filter, especially when filtration is continued for 

 some time. 



Another application of the method of filtration may be 

 noted. It has been stated above (p. 16), that when multiple 

 doses of immune-body are united to red corpuscles, the sub- 

 sequent lysis by a dose of complement does not set free 

 the surplus molecules of immune-body ; in other words 

 the combination of immune-body with receptors is not 



1 The pores of the filters become choked more quickly than when the 

 corpuscles are laked with water. The later portions of the filtrate are, 

 however, found to be free from receptors. 



MUIB 



