A. C. Coles 57 
These more closely resemble the haemogregarines so commonly found 
in the blood of fishes. 
Occasionally, especially in smears made from the lung, the haemo- 
gregarine is seen lying in a distinct capsule, and the margin of the 
latter extends in the form of a bow along the concave side of the 
parasite and is usually much more evident in the case of the parasites 
with a recurved pointed extremity. (Plate V, figs. 7 and 8.) 
The whole parasite has then somewhat the appearance of a malarial 
crescent with its bow-—the remains of a corpuscle. At first I was 
inclined to regard these forms as parasites situated in a red cell, but I 
think it more probable that the parasite is enclosed in a cyto-cyst as 
Miss Porter (1908) has described in the case of Leucocytozoon muscidi. 
Another but very rare form of haemogregarine was occasionally found 
in smears made from the lung and liver. 
This takes the form of a long, somewhat narrow, slightly curved 
shaped body, in which both ends taper and are rounded, but one end is 
sometimes more pointed than the other. The nucleus is oblong in 
shape and is situated slightly nearer the thicker end. (Plate V, 
figs. 4, 5, 6.) 
The size of the free haemogregaiines varies somewhat. The oval 
or kidney shaped forms usually measure about 10 /r long by 4’5 /x 
broad, and their nucleus about 6 /x in length and 4 o /x in transverse 
diameter. 
The long slightly curved parasite measures from 16 to 18 y, long and 
only about 3 y in width, whilst the nucleus averages about 8 y in 
length and 3 y in transverse diameter. 
Intraleucocytic Haemogregarines. Parasites contained within the 
protoplasm of mononuclear leucocytes were found in heart blood, liver 
and lungs—but were most numerous in the heart and lung. (Plate V, 
figs. 9, 10, 11.) The enclosed haemogregarine is nearly always of the 
sausage or kidney shaped form, and it evidently produces a marked 
karyolysing action on its host. In most cases the parasite has invaded 
and split up the nucleus, and the protoplasm has become discoloiu'ised 
and in some cases almost invisible. 
Very often the parasite lies between jjortions of the nucleus of the 
leucocyte, and it is usually surrounded by a narrow margin of uncoloured 
area, probably a cyst. 
Multiplication cysts of Haemogregarines were found in very small 
numbers in the heart blood, liver and lung. These are oval, rarely 
round, structures surrounded by a narrow unstained halo—the capsule. 
(Plate V, fig. 12.) 
