1910. | Some Enumerative Studies on Malarial Fever. 171 
may be able to survive for longer periods. In Cases 20, 22 and 23, they 
appeared in increasing numbers for 4 to 6 days after continuous 30-grain 
doses of quinine had been commenced, suggesting that the drug has no effect 
upon them when they have once been generated. But quinine appears to 
affect the numbers of crescents indirectly by cutting off the source of supply. 
Though many researches upon the effect of quinine on crescents (a subject of 
the greatest sanitary importance) have been attempted, so far as we know, 
the possibility of a constantly continued supply has not previously been taken 
into consideration. We are continuing researches on the point. 
11. The Leucocytes were counted frequently, but not always daily ; at first 
by the hemocytometer, but in the later 20 cases by the thick-filn method. 
The latter method has the advantages of putting the leucocytes closer 
together and of enabling us to estimate them at the same time with the 
parasites; but, like the hemocytometer, it is not very appropriate for 
differential counts, because of occasional uncertainty in distinguishing the 
various kinds. Accordingly, these were made (in six cases) by thin film, 
500 cells being examined on each occasion. 
Our results are, as shown in all the cases, that during the pyrexial periods 
the total leucocytes are comparatively few, being frequently as low as 
2000 to 3000 per cubic millimetre (Cases 17,18, 23, 24, etc.). But as 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 cubic millimetre (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 
7 days after the fever has abated their numbers are markedly increased 
and vary much. ‘The so-called mononuclear percentage was always in 
excess throughout the cases, even long after the 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 total mononuclears 
to polymorphonuclears is about 35 per cent., but in our cases it was often 
60 per cent, and in Case 30 reached 80 per cent. It tends to fall slightly 
with great improvement in health. During the individual daily paroxysms, 
as shown by Stephens and Christophers, the total mononuclears are rathér 
low during the height of the fever, but show a marked increase during the 
following remission. This increase is chiefly due to the large mononuclears. 
This process is repeated with each paroxysm, and if a paroxysm fails the 
