80 THOMPSON YATES AND JOHNSTON LABORATORIES REPORT 
The parasites — that is, the little bodies originally described by Leishman — ■ 
occur in these specimens under two conditions, namely : — 
(a) embedded, singly or in groups, in a matrix ; 
or (b") free in the serum. 
The matrices in which the bodies are embedded appear to consist of very 
delicate protoplasm, which stains a faint violet or mauve colour, and has a cloudy, or 
perhaps granular or even stromatic structure. The outline is generally sharp, but 
without a limiting contour suggestive of a cell wall. The shape is most commonly 
oval, but is sometimes quite irregular, as if the substance had been torn in pieces. 
The size of these masses of protoplasm varies greatly — from 3 n to 8 /m. in the long 
diameter ; and they show no indication of possessing either nucleus or haemoglobin, 
or even granulations similar to those of leucocytes. It is, therefore, scarcely likely 
that they are derived from either the red or the white corpuscles. They contain no 
pigment or fatty granules. 
Embedded in these masses of protoplasm we find one or more of Leishman's 
bodies (Figs. 2-1 1). I have counted as many as twelve in one mass ; and have drawn 
another mass containing eight. !6! From one to four appear to be the commonest 
number ot bodies contained in each mass. Very often the mass is only partially 
occupied by the bodies (Figs. 7, 9) ; but in such cases one does not observe any 
indications suggesting vacancies left by bodies which have dropped out of place. 
Occasionally one finds clusters of the bodies connected only by faint relics of the 
matrix, or even by none at all. 
When contained in such matrices, Leishman's bodies have the following 
characters. They consist of a large and a small mass of deeply red chromatin, 
surrounded by a clear area. We may provisionally call these masses the macronucleus 
and micronucleus respectively. The former is roughly spherical, dense, and about 1 /j. 
in diameter. The latter is generally (perhaps always) rod-like ; about 5 /u or more 
in length ; stained still more deeply than the macronucleus ; situated about 1 ju from 
the centre of the latter, and lying in various relative positions in regard to it. Some- 
times no micronucleus is to be seen, but this may be only because it is hidden by the 
larger mass. At other times it appears only as a deep red dot, but this may be due to its 
end-on position with regard to the observer ; and it is not possible to determine these 
questions in dried preparations. 
The clear area surrounding the twin chromatin masses extends a very little 
distance beyond them, and, when the bodies are contained in a matrix, is not usually 
defined by an outer contour — -although this is sometimes the case. 
It should be noted that these embedded varieties of Leishman's bodies are 
found only in the two preparations made intra vitam. 
The free forms (Figs. 12-30) are precisely similar to the embedded forms, 
except that they possess a distinct, and apparently resistant, oval cell wall, from 2*5 /u 
