A. C. Coles 
33 
a very small number of haemogregariues were found in smears from the 
liver, and an occasional one from the spleen, but none were detected in 
films made from the bone marrow. 
The haemogregarines were in one vole associated with Graham- 
Smith’s bodies, Grahamella, both in the red corpuscles and in clusters 
free. In the other vole many of the large uniuucleated leucocytes 
contained in their protoplasm a number of large spherical or oval 
granules which stained very deeply. Some of these granules measured 
as much as 3 fx in diameter. 
Should this haemogregarine prove to be a new species, I would 
suggest that it be distinguished by the name Haemogregarina microti 
sp. n. 
Haemogregarine in the Rat (Haemogregarina muris). 
These were found in three common rats {Mus decumanus) all of 
which were dead, and two much mauled when examined. Haemo¬ 
gregarines were seen in films from the peripheral and heart blood, but 
not in those made from the liver, spleen or bone marrow. They were 
very scanty in the peripheral blood, but numerous in the blood taken 
from the thoracic and abdominal cavities, in which case they were 
contaminated with bacteria, probably from the gut. 
The haemogregarines are somewhat crescentic, bean or sausage¬ 
shaped. The ends are round, generally equally so, but sometimes one is 
more pointed than the other. (Plate II, fig. 16.) 
The body stains a bluish colour, and one end often a red colour 
whilst the nucleus stains a deep crimson colour with Giemsa. The 
protoplasm is granular and usually contains chromatoid granules which 
are most marked at one end and constitute a polar cap. Vacuoles 
are sometimes seen in the protoplasm. 
The nucleus which consists of coarse granules of chromatin is 
frequently placed at one end, which may be pointed or somewhat hook¬ 
shaped, whilst the other end is packed with red granules. The nucleus 
in some cases shows a prolongation in the form of a very narrow line 
leading up to and terminating in a deeply stained granule. 
The staining varies considerably ; the greater number are stained 
a brilliant blue, some very deeply, others very faintly, whilst others are 
a pale red colour with numerous lightly stained granules scattered 
throughout the protoplasm. The nucleus, also, varies in its staining 
reaction; it may be deeply stained and appear almost black, or it may 
Parasitology vii 
3 
