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the asexual forms and the fever diminish the total leucocyte curve 
rises, and about seven days later exceeds the normal and may reach 
20,000 and even, rarely, 30,000 per c.mm. (Case 7)—though this 
height is not maintained. The very high counts seem to be associated 
with much quinine. We observed generally that the so-called 
polymorphonuclear leucocytes, though rather few during the 
pyrexial periods, do not vary much from day to day, but about 
seven days after the fever has abated their numbers are markedly 
increased and vary much. The so-called mononuclear percentage 
was, however, always in excess throughout the cases, even long 
after disappearance of all forms of the parasites for six 
weeks afterwards in Case 1, though quinine had been given 
daily during that period (out of hospital). We think, therefore, that 
a high mononuclear percentage is likely to be always of value in 
diagnosis in the absence of parasites. The normal ratio of all 
mononuclears to polymorphonuclears is about 35 per cent., but in 
our cases it was often 60 per cent., and in Case 3° reached 80 per 
cent. It tends to fall slightly with great improvement in health. 
Thus the total leucocyte rise appears to be due chiefly to mono¬ 
nuclears. During the individual daily paroxysms, as shown by 
Stephens and Christophers,* the total mononuclears are rather low 
during the height of the fever, but show a marked increase during 
the following remission, this increase affecting chiefly the large 
mononuclears. This process is repeated with each paroxysm, and 
if a paroxysm fails the mononuclears remain increased (Case 9 
especially). But we could not always find these variations in the 
absence of fever and many parasites. This mononuclear reaction, 
which we have also seen in our case of trypanosomiasis, appears to 
be exactly comparable to the polymorphonuclear reaction described 
by F. W. Andrews (‘Lancet,’ June, July, 1910) as generally 
occurring in bacterial diseases. 
12. Various therapeutic agents. Methylene blue was tried m 
three cases in 12 grain daily doses; the parasites diminished, but 
we cannot draw any conclusions from the figures. In Case 24, 
altogether 36 grains of soamin were injected intramuscularly in 
’ The increase in the number of large mononuclear leucocytes as a diagnostic sign of 
Royal Society’s Malaria Committee Reports, Fifth Series, 1901. Harrison & Sons, London. 
