INFECTION IN INTERMEDIATE HOST: FALCIPARUM 
199 
the two peaks of the remittent paroxysm 
will commonly be less than 24 hours, and 
that between the two peaks on either side 
of the intermission, greater than 24 hours. 
Marchiafava and Bignami (1901) described 
the typical estivo-autumnal tertian fever 
curve as comprising the invasion of fever, 
the period of pyrexia, the pseudo crisis, the 
precritical elevation,- and the true crisis.' 
Their graphic illustration resembles essen¬ 
tially what we described as a partial mer¬ 
ger of two paroxysms to form a remittent 
curve. Perhaps this should be called an 
intermittent-remittent arrangement when 
continued throughout. As Mannaberg notes, 
however, this type of curve is not by any 
means constant for this infection. Occa¬ 
sionally one observes that in quotidian 
courses one cycle provides paroxysms of 
short duration and the other, elevations of 
temperature with broader bases (Fig. 4, No. 
1210). Patient 1199 (Fig. 3) exhibited re- 
mittency involving three paroxysms. Here 
the temperature remained above 99° F 
for at least 64 hours. 
In courses that start as tertian in type 
one frequently notes the sudden or gradual 
appearance of a second cycle (Fig. 3, No. 
1199) resulting in quotidian paroxysms; or 
one may see one cycle drop out of a quo¬ 
tidian course (Fig. 5, No. 1205), leaving ter¬ 
tian paroxysms. Occasionally, as in the case 
of Patient 1205 (Fig. 5), one cycle may dis¬ 
appear temporarily, perhaps missing one or 
two paroxysms, to return again. Also a 
second paroxysm may appear in a tertian 
course following which the original cycle 
may drop out. Many variations may thus 
be provided by the appearance and disap¬ 
pearance of cycles. In addition to irregu¬ 
larities of the intermittent, remittent, or 
continuous types of fever curve, one may 
note that the arrangement of the paroxysms 
shows irregularities^ These features fre¬ 
quently combine to form febrile courses 
which, on superficial examination, would 
appear to be entirely without order. On 
closer study, however, despite the irregu¬ 
larities most of them will be seen to possess 
some design. Basically they comprise one 
or more tertian cycles with modifications 
such as (a) the appearance and disappear¬ 
ance of extra cycles, (b) the transitory and 
close approximation of two quotidian cycles 
so as to produce a remittent curve, or (c) 
the breaking up of a single fever peak to 
produce two or three secondary elevations 
(Fig. 1, No. 258) during the course of the 
paroxysm and a very broad base thereto. 
The tendency of falciparum paroxysms to 
anticipate or postpone in relation to the 
time of the previous one is much more irre¬ 
gular than in the case of P. vivax infections. 
As previously indicated, the lack of 
regimentation, or synchronization, in sporu- 
lation of P. falciparum is apparently re¬ 
sponsible for the irregularities noted both 
in the individual paroxysm and in the 
arrangement of paroxysms in the course of 
the infection. It is realized that variation 
in individual sensitiveness may, of course, 
play some part, but the irregularities are 
so nearly constant that this factor would 
seem to be of relatively minor importance. 
Thompson and Woodcock (1922) and James 
(1922), however, prefer to ascribe the dis¬ 
orderly paroxysms to the variable time re¬ 
quired by individual parasites within a 
group to complete schizogony. It would 
seem more reasonable to assume that such 
irregularities are due to various broods of 
parasites sporulating asynchronously rather 
than to presuppose a confused alternation 
in the length of the schizogonous cycle of 
groups of parasites. Unfortunately smears 
from the peripheral blood do not usually 
reveal the mature forms or schizogonous 
cycle of P. falciparum. 
Relationship between parasite density 
and the paroxysms. Following are several 
points of interest in the relationship be¬ 
tween parasite density and the incidence of 
paroxysms. Between individuals of the 
white and black races there is quite a 
marked difference in tolerance for P. falci¬ 
parum. We have commonly observed in 
infections among negroes that the parasites 
may attain densities of several thousand per 
cmm before a febrile reaction is provoked. 
A count of over 71,000 was noted on the 
first day of fever in one instance. In this 
case the parasites had first appeared in the 
