36 Transactions of the Boyal Society of South Africa. 
changes, but on examination of the blood the presence of a Leucocytozoon 
was frequently noted. 
So far in South Africa a similar parasite had only been observed in some 
species of wild birds, e.g., a hawk, and consequently from an economic 
point of view its presence was not considered of much importance. It 
will now, however, be necessary to ascertain whether it enters into the 
etiology of some of the at present unknown diseases of ostrich chicks. 
Microscopical appearance of the Parasite in Stained 
Blood-smears. 
In dried blood-smears fixed with methyl alcohol and stained with 
Giemsa, two main types of parasites, which apparently correspond with 
male and female Gametocytes, have been noted. 
The Female Gametocyte occurs most frequently. 
The shape varies. Sometimes it is more or less rounded, but it may be 
irregular, probably due to distortion caused in making the smears. 
The size varies from 11-15 microns in length and 9-13 microns 
in width, the rounded form being generally from 14 to 15 fi in 
diameter. 
The protoplasm of the parasite stains deeper than in the case of the 
male gametocyte, and scattered throughout it are a number of meta- 
chromatic granules, which appear more distinctly in some of the parasites 
than in others. A number of small clear spaces occur throughout the 
protoplasm. Situated in various positions, generally at the centre or near 
the edge, is an aggregation of small chromatin granules which represents 
the nucleus. 
In most instances a large chromatin granule, situated in the mass of 
the chromatin granules or at the side of or some distance from these, 
stands out distinctly. 
The nucleus of the host cell is always altered in shape. In most cases 
it is elongated and enlarged and situated at the margin of the parasite. 
The Male Gametocyte, as stated above, occurs less frequently than the 
female. 
The shape varies. It is usually more or less rounded. 
Size. The rounded forms average 9 to 10 in diameter. 
The protoplasm stains less densely than in the case of the female. 
The chromatin granules of the nucleus are generally scattered through- 
out the cell, and sometimes they are large and widely separated, in which 
case they are very distinctly seen. 
The nucleus of the host cell is irregular in shape but less elongated and 
smaller than in the case of the cell invaded by the female. It is found at 
the edge of the parasite. 
