168 Major R. Ross and Dr. D. Thomson. [ Oct. Tz 
in a patient who contains, say, 3,000,000 cu. mm. of blood. The 
speculation regarding parthenogenesis in malaria, and the case of 
Schaudinn supposed to support it, have been criticised elsewhere by one of 
us (R. R.).* In two of our relapsing cases (19, 26), no sexual torms at all 
were found during 35 different thick-film examinations. Even if they were 
present in small numbers (crescents do not collect in the spleen), yet the 
numbers of asexual parasites found in or just before the relapses (24 and 400 
* per cu. mm.) cannot be explained by parthenogenesis unless we suppose that 
each sexual form produced by “gametoschizogony” 840 or 14,000 spores ! 
Until better evidence for such views is adduced, our results justify the 
doctrine that the malarial infection is kept continuously alive simply by the 
persistence of the asexual forms in varying numbers, and that fever occurs 
only when the forms are numerous enough to produce it. 
9. The Effect of Quinine on the Asexual Forms.—Yhe destructive effect of 
the drug is, of course, everywhere recognised, though very little completely 
satisfactory statistical evidence can be cited in. proof. Many laborious 
researches have been made regarding the comparative utility of the various 
salts, but these have been confined almost entirely to estimating the rate and 
percentage of absorption, judged from urinary elimination. The subject is of 
the greatest sanitary and medical importance; but, so far as we can see, it 
can be usefully studied only by the more detailed enumerative analysis 
which we propose soon to undertake. Our daily analysis gives a little 
more light; but the following figures may be mentioned. Cases 15 and 16 
showed no asexual forms; Cases 11 and 13 were so severe that quinine 
was given at once; Cases 1, 5, 27, 31 and 32 were so mild that quinine 
was withheld during the period of observation ; and in the remaining cases 
the drug was withheld only for some days (except an occasional necessary 
dose), and was then given continuously while the parasites were still being 
counted. We have therefore added together all the daily counts during 
the periods of no-quinine and quinine respectively. With eight cases of 
P. vivax there were 45 no-quinine days, showing 104,032 total parasites, or 
an average of 2,312 a day; and there were 74 quinine days, with 31,769 
total parasites, or an average of only 429 a day (one-fifth). With P. fale- 
parum (19 cases), 147 no-quinine days showed an average of 3,136 asexual 
forms, and 148 quinine days an average of 1,535 (one-half). We should 
have expected that the proportion of quinine-day parasites would have 
been smaller; but the no-quinine counts are diminished by the inclusion 
of the five mild cases and also by doses of 10 to 20 grains which were 
given on 10 isolated occasions. On quinine days the doses were generally 
* ‘Prevention of Malaria’ (Murray, 1910). 
