1910. | Some Enumerative Studies on Malarial Fever. 169 
20 to 30 grains a day, and Cases 11, 13, 14,15 and 16, and parts of other 
cases are omitted because they were unsuitable. Great falls in the number 
of parasites occurred, even without quinine, in Cases 5,17 and 26; while, 
on the other hand, small numbers of asexual forms remained in some cases 
for five or more days in spite of considerable daily dosage. In Case 23 a 
severe relapse began six days after the stoppage of quinine tannate, which had 
been given for nine previous days in 10 to 30 grain doses daily. No other 
relapses occurred after continuous quinine treatment; but 12 occurred 
without it. 
10. Observations on the Sexual Forms.—It is, of course, generally held—and 
probably quite rightly—that these are developed (by a cytological process not 
yet clearly seen) from the asexual forms. But, at the same time, no one has 
been able to note any correspondence between their numbers—many of 
the former may be present when the latter are very scarce, and vice versd. 
This rule, which is fully confirmed by our figures, has always been difficult 
to reconcile with the accepted theory of origin. On comparing our curves, 
however, the remarkable fact was observed (by D. T.) that there often seems 
to be indeed a correspondence, but that it is delayed for from 8 to 10 days— 
that is, that the sexual curve tends to rise that number of days after a rise 
in the asexual curve. Out of our 25 infections with P. falciparum 18 
showed crescents, and of these Cases 14, 22, 17, 18, 20, 23, 24 and 30 
suggest this phenomena, while in 17 and 20, the rises are sufficiently 
isolated to show it most distinctly. In Case 17, asexual rises existed on the 
1st to 3rd days, the 11th to 12th and the 21st to 22nd days, separated by 
apyrexial periods during which few asexual and no sexual forms were found ; 
but on the 30th day (eight days after the last relapse) crescents appeared for 
the first time. : In Case 20, an asexual relapse commenced on the 17th day 
and reached its height on the 20th day. Avery few crescents had been found 
all the time; but a marked rise in their numbers commenced on the 26th day 
and reached its height on the 28th day. The most ready explanation is that 
the crescents require 8 to 10 days for development, during which they remain 
undetected, probably in the internal organs of the host. This is confirmed by 
the fact that numerous small ones are seen at the commencement of a rise; 
and also by the observation (frequently made) that in fresh infections the 
crescents seldom appear until a week or more after the first attack of fever. 
Strong confirmation is also given by Case 6, in which Dr. Fantham noted a 
sudden appearance of sexual forms (P. vivax) on the 11th day, 7 to 10 days 
after the original asexual rise, and after the patient had been taking 30 grains 
of quinine daily for a week, suggesting that the same phenomenon holds for 
P. vivax also. 
