322 Messrs. Hayden and Morgan. Influence of the [Aug. 24, 



Experiment 3. — The following phagocytic mixtures were used : — 



(a) Equal volumes of 



Corpuscles. 

 Suspension of bacilli. 



Two volumes of a mixture of equal parts of a suspension of detritus and serum 

 which had been previously incubated for 20 minutes. 



(b) Equal volumes of 



Corpuscles. 



Suspension of detritus. 



Two volumes of an incubated mixture of the suspension of bacilli and serum. 



(c) Equal volumes of 



Corpuscles. 



Suspension of detritus, and 



Two volumes of an incubated mixture of saline and serum. 

 The following were the phagocytic counts : — 





(«) 



(*) 



(c) 



Patient i 



0-15 



1-59 



1 -20 





0-22 



1-81 



1 09 





0-19 



1-37 







0-19 



1 74 



1 -20 



Patient iii 



0-20 



1-36 



1 -12 



These experiments supplement the previous ones, in the respect that they 

 show that the addition of detritus diminished phagocytosis by removing the 

 opsonic power from the serum — in other words, that the detritus functions 

 as a receptor. And we may conveniently speak of the receptors of the 

 detritus as free receptors, in contrast to the fixed receptors of the intact 

 bacilli. 



Column (a) shows that the serum, when digested first with the free 

 receptors, will combine with these to the practical exclusion of the fixed 

 receptors which are afterwards added. Column (b) shows that the serum, 

 when digested first with the fixed receptors, will now combine by preference 

 with these, and Column (c) that, when free and fixed receptors are present, 

 the serum at one and the same time will tend to combine more impartially 

 with both. 



Row docs the Absence or Presence of Detritus in the Bacterial Suspension 

 Influence the Opsonic Index which is arrived at ? 

 Experiment 4. — Indices were estimated by using phagocytic mixtures of — 

 Corpuscles, 



Suspension of bacilli, and 

 Serum. 



