22 
MALARIA 
(1900) described a plasmodium of distinct 
morphological character which he found 
occurring in the blood of soldiers returning 
from the Philippines. Emin (1914) named 
a form which he found in the blood of some 
pilgrims in Camaran Island P. vivax var. 
minuta. Craig (1926) accepted Emin’s 
form as the one earlier described by him but 
not named. Later Craig (1933), after 
studying slides of P. ovale obtained from 
Yorke, James, Nicol and Shute, came to the 
conclusion that the parasite described by 
him in 1900 was P. ovale Stephens and not 
P. vivax var. minuta Emin as he had pre¬ 
viously thought in 1926. 
Ziemann (1915) studied the Camaran 
Island parasites and was so convinced of 
their separateness that he gave them the 
name P. camarense. Ziemann (1938), how¬ 
ever, says that he believes Emin’s parasite 
should be considered as a variety of P. 
vivax. 
Wenyon (1926a) states that he has seen 
similar forms in Mesopotamia and Mace¬ 
donia but regarded them as aberrant P. 
vivax or P. malariae. 
P. falciparum quotidianum Craig, 1909. 
Craig and Faust (1940) are of the opinion 
that Grassi and Feletti (1890) described 
this form in part and that later Marchia- 
fava and Bignami (1891-1892) called it 
“the quotidian aestivo-autumnal plas¬ 
modium.” Craig (1909) studied several 
infections with this organism and became 
convinced of its separateness from the true 
P. falciparum. This* plasmodium was said 
to produce a paroxysm every 24 hours; the 
gametocytes were crescentic but smaller 
than the typical P. falciparum. The rings 
were rich in chromatin and the schizonts 
produced 6 to 18 merozoites with an average 
of from 12 to 14. For this plasmodium 
Craig proposed the name P. falciparum 
quotidianum. 
Ziemann (1938) states that he has never 
been able to recognize this quotidian form 
and, therefore, questions its validity. Gio- 
vannola (1938) believes that further study 
is needed before a definite decision can be 
given. 
P. perniciosum Ziemann, 1915. Ziemann 
studied a malignant tertian malaria in the 
Cameroons and became convinced of its 
separateness from the typical falciparum 
infection in Italy and other countries. This 
form was said to produce only a small quan¬ 
tity of dark pigment. There was complete 
disappearance of the parasites from the 
peripheral blood after ring formation. The 
infected cells have a “brassy” tint. The 
schizonts occupy only one-third to one-half 
the diameter of the infected cell and the 
merozoites number 12 to 16. The gameto¬ 
cytes are smaller and are not produced 
abundantly. 
Wenyon (1926a) states that he has stud¬ 
ied both the European and West African 
types of P. falciparum and has frequently 
observed the African form to behave en¬ 
tirely opposite to that ascribed to it by 
Ziemann. As a consequence, he thinks there 
is little reason for accepting P. perniciosum 
as a distinct species. 
Ziemann (1938) still holds for the sepa¬ 
rateness of this type but now considers it 
a variety or subspecies of P. falciparum. 
In this later paper he lists the character¬ 
istics again but says the schizonts produce 
only 10 to 12 merozoites in contrast to 12 to 
16 as given by him in 1915 and that sickle 
forms are not seen. Also, this form is more 
resistant to quinine than the typical P. 
falciparum. 
Raffaele and Lega (1937) described the 
differential characteristics of parasites 
which they found in some malignant tertian 
cases from Italian East Africa, and because 
these forms were shorter and broader and, 
especially in the males, less falciform, they 
proposed to recognize this type as a new 
variety for which they proposed the name 
P. falciparum var. aethiopicum. Later Gio- 
vannola (1938) concluded that the Aethi- 
opian strain is probably identical with Zie¬ 
mann’s perniciosum. 
P. wilsoni Roberts, 1940. This recently 
described parasite was first seen by Dr. 
Bagster Wilson in the blood of two African 
patients from Tanganyika and has since 
been found by Roberts (1940) amongst all 
races in East Africa. According to the 
description, the young trophozoites are very 
