14 QUATERCENTENARY STUDIES IN PATHOLOGY 



(4) Typical lymphocytes. 



(5) The vacuolated large mononuclear cells. These latter cells were 



first noted by Kurloff in the blood of the guinea-pig. In their 

 morphology, they correspond to the large mononuclear 

 leucocytes of man. The protoplasm of these cells, however, is 

 highly vacuolated, and included in the vacuole is a round or 

 oval granular mass, staining a dull-red with Leishman's stain. 

 It is impossible here to discuss the question of the nature of 

 these bodies enclosed in the cytoplasm of the vacuolated cells. 

 The whole subject has recently been treated in detail by one 

 of us (Ledingham) (^9). 

 The following are the average counts (total and differential) recorded 

 by Kurloff, Burnett (38), compared with our own observations : — 



Burnett. Kurlofif, Ledingham. 



In the control guinea-pigs, as in the control rabbits, the variations in 

 the total and differential counts throughout the day were found to be 

 quite trivial. 



III. — Fluctuations in the opsonic index in healthy animals 

 during short periods. 



Does the opsonic index in healthy animals vary throughout the day 

 or from day to day? To settle this important question numerous 

 investigations were made, some of which we may here quote. 



Opsonic indices of two healthy rabbits, C and E, on five successive 

 days. (C taken as control.) 



Date. Opsonic Index. 



29/1/05 C=i*o E=i'o 



30/1/05 C= I'o E = 1-2 



31/1/05 C=ro E- -98 



1/2/05 C=i'o E= '98 



2/2/05 C = i'o E= '98 



(334) 



