36 
Blood Parasites 
towaz’ds the margin of the red corpuscle. The nucleus usually takes the 
form of a half or quarter segment of a circle. The protoplasm of the 
infected red cell shows no alteration in its staining reaction and no 
pigment is present. 
These forms were very infrequently seen, not more than four or five 
being found in some 36 films which were very carefully examined. It 
is quite possible that these might not have been the young forms of the 
pigmented parasite but varieties of the unpigmeuted intracorpuscular 
parasite or Acltromaticus. 
2. Somewhat larger oval-shaped parasites measuring about 3 /r in 
diameter. The cytoplasm stains a pale blue and contains no pigment. 
The nucleus takes the form of a small segment of the oval or ring, or 
appears as a small oat-shaped mass situated at the" margin of the 
parasite. 
Not infrequently a very delicate line of nuclear matter extends from 
the nucleus right across the body and terminates in a spot lying near 
the margin which stains the same colour as the nucleus. I suppose by 
some this small body would be I’egarded as of the nature of a centi'osome, 
but probably it might more correctly be considered as an extra-nuclear 
karyosome. This vaiiety is also very seldom met with. 
3. Still larger round or oval bodies measuring 4 /a in diameter, 
staining more deeply blue and with the nucleus situated towards the 
margin. One or more chromatinoid granules may be found in its 
interior, but there is no pigment, and the protoplasm of the red blood 
corpuscle shows no granules or polychromatophilous staining with 
Giemsa or Leishman’s stain. 
4. Parasites filling up | or f of the red cell, measuring about 5 /a, 
stained a deeper blue colour, with the nucleus situated towards the 
margin and from which occasionally a very fine line can be traced to a 
red stained granule lying in the protoplasm. The latter contains a small 
amount of pigment scattered throughout the protoplasm. 
5. Parasites, circular nr oval, showing no remains of the red cell, and 
containing much pigment. These are slightly lai’ger than the surrounding 
red corpuscles and generally measui’e 6 to 7'5 /a in diameter. 
Two types of these can be recognised, the macrogamete which stains 
a deep blue colour and in which the nucleus is compact, and the micro- 
gametocyte which stains either a faint blue colour and contains a diffuse 
large nucleus, or a distinct red colour in which it is difficult to determine 
precisely the boundary of the nuclear chromatin. Some of the latter 
are stained such a deep red colour, that they might very easily be 
