C. A. Hoare 
317 
perhaps dealing with a ripe trophozoite or schizont, in which the first indica¬ 
tions of the asexual process of multiplication are present. The average 
measurements of this form are 14/x in length, in breadth. 
Besides this form, sometimes a second is encountered (Plate XVIII, fig. 1). 
which is more slender, with a smaller nucleus of more compact structure. 
One end of this form is always bent over in the shape of a small tail. In this 
form also the light surrounding rim 1 is more sharply outlined, and it is possible 
that it represents an earlier stage. 
In form and size the haemogregarine resembles that described by Dutton, 
Todd and Tobey (1907), also from a Puff-adder. However, the briefness of 
their description, and the drawings, do not establish the identity of these 
two forms. Plimmer (1912) also mentions some haemogregarines found by 
him in Bitis arietans, but his description is still briefer; he characterizes them 
by only three words "medium, host-cell unaltered.” Similar forms were 
described by Minchin (1910) from a snake in Uganda, but the host is unre¬ 
corded. He also examined the blood of a Puff-adder, but with negative results. 
As regards the classification of the haemogregarines from snakes, Lutz 
(1901) considered it possible to unite them all in one species —Drepanidium 
serpentium; most authors, however, follow the principle set forth already by 
Simond (1901), according to which a definite species of haemogregarines is 
peculiar to each host species. Dobell (1908) adopts the same view for practical 
reasons. On the other hand, Sambon (1908) regards the haemogregarines of 
allied host-species as “host-varieties” or ‘ w host-races,” corresponding to the 
geographical races” of certain free-living animals. At present, however, the 
haemogregarines are still so inadequately worked out, and so few complete 
cycles of development are known, that it is impossible to adopt any of these 
views unreservedly. For practical reasons, Simond s view may be adopted 
provisionally. 
Because neither Dutton, Todd and Tobey, nor Plimmer gave specific 
names to the haemogregarines found by them, and, because of the opinion 
just expressed by me, I propose to name the parasite herein described as 
Haemogregarina dogieli, in honour of Professor V. Dogiel. 
Host: labelled Snake No. 5 (“green tree snake”), from Mabira, June 19, 1914. 
In this host the parasites are also intracorpuscular exclusively (Plate XVIII, 
figs. 5, 6, 7). The erythrocytes are infected in a very slight degree. The 
haemogregarines usually attain the length of the host cell, or are somewhat 
longer, slightly bending with their ends inwards. The influence of the para¬ 
sitism on the host cells is distinctly visible. In my preparations nearly all 
the erythrocytes infected are diminished in size; as compared with the normal 
blood corpuscles, their cytoplasm stains very feebly, and, in some cases, there 
seems to be only a shadow of it visible (dehaemoglobinization). The nucleus 
1 The subject of “light areas,” 
paper. 
“rims,” or capsules in general, is discussed at the end of this 
21_2 
