A. C. Coles 
55 
some the individual members of the group are very clearly defined, 
whilst in others they are more or less fused together. 
The avei’age measurement of the free Toxoplasma is about 5 to 6 /r 
in length and 2 to 3 /r broad. Compact groups of four parasites, 
usually circular in outline, measure about 7 /x. in diameter, whilst not 
infrequently, especially in the liver, more rarely in the lung, group.s of 
50 to 60 elements measuring 25 p or more in diameter, were met with. 
The protoplasm is alveolar and stains a bluish, less frequently, a 
bluish-red colour with Giemsa. It often contains chromatoid granules 
but vacuoles were seldom seen. 
The nucleus, stained a brilliant-red with Giem.sa, is generally 
situated about the middle of the body, sometimes hoAvever it is nearer 
one end than the other. It consists of an irregular mass of chromatin 
granules. 
No definite centrosorne can be made out, although the nucleus not 
infrequently stains more deeply at one point at the margin. 
Near the nucleus one or two deeply stained granules are often seen, 
whilst in some of the parasites a fine red stained line can be seen 
extending fi’om the nucleus to a granule situated at one pole of the 
body. (Plate V, figs. 13 and 14.) 
Intracellular Toxoplasma. The Toxoplasmae are found in the 
protoplasm of the mononuclear and occasionally polynuclear leucocytes, 
and in the large endothelial cells. (Plate V, figs. 20 and 21 .) Occasion¬ 
ally a single parasite or its remains could be detected in a liver cell. 
The number of parasites enclosed in the host cell is very variable, 
sometimes there are only one or two, at other times the protoplasm is 
crowded with them. They may be different throughout the cytoplasm 
or grouped together in masses. 
On one occasion I found a leucocyte containing a Haemogregarine 
and also a Toxoplasma. 
In many cases it is difficult to determine the exact outline of the 
individual parasites aud at times the nuclei and granular debris are all 
that remains. 
This may be explained (a) by post-mortem changes which have 
taken place as the organs were not examined till 24 hours after death, 
(/3) by phagocytic action of the host cell, or ( 7 ) by some secretion of the 
parasite itself 
Although round masses of 20 to 30 or even 60 parasites were not 
infrequently found, and which to some extent resembled cysts, yet 
there was no evidence of a capsule (Laveran and Marullaz, 1913, speak 
