220 



followed again by a marked leucopenia which is at its 

 maximum before the onset of the next attack. 



we . , , i i 



-pr-^r instead of - may be 

 RC 500 800 



Billet (Fig. 71), who has traced out hourly the 

 relation of the leucocyte curve to the temperature 

 curve, has shewn that in regular curves of the tertian 

 or quartan type, the leucocytic curve follows closely 

 the variations in the temperature. Thus, before the 

 febrile attack in a quartan, there may be a leucopenia 



represented by = - - ; at the time of the attack, 



i\.v_x 1 2OO 



however, there is a leucocytosis of -^-~- = . 



RC 200 



This gradually disappears, passing through the 

 normal value - , and again reaching a marked leuco- 

 penia before the next attack. The variations are of 

 the same kind in irregular temperatures, the leucocy- 

 tosis corresponding to the rise of temperature, and the 

 leucopenia to the apyretic intervals. 



The Percentage Value of the Leucocytes. If we 

 now make a differential count in a stained specimen 

 we shall be able to ascertain what change, if any, there 

 is in the relative percentage of the different kinds. 



1. The main characteristic change is that there 

 is an increase in the percentage of large mononuclears, 

 so that at times they may even outnumber the poly- 

 nuclear. 



2. The change is especially well-marked in the 

 periods of apyrexia'-(z.^., when there is a leucopenia). 

 When there is a leucocytosis the increase in the mono- 

 nuclears may nat be apparent. 



