REPORT OF TRAVELLING PATHOLOGIST AND PROTOZOOLOGIST 
147 
red stone which abounds in this district. The parasite in question occurred in the blood 
with two other parasites, one a haemogregarine and the other a trypanosome. The three 
parasites were quite independent of one another, there being notbing to indicate that they 
represented different stages of any one parasite. 
The parasite to he described here resembles in many respects the Plasmodium {Proteosoma) 
of birds. It is a pigmented intra-corpuscular parasite of tbe red cell, and is found in three 
distinct forms—viz., male and female gametocytes and schizonts. 
The youngest forms are found in close association with the nucleus of the red cell, and 
this position is maintained during the trophic stage. While in contact with the nucleus the 
parasite is very amoeboid, and is seen as numerous pseudopodia extending from the nucleus 
into the body of the red cell (Plate XII., figs. 1, 5, 7-10). In many of these stages it appears as 
if the parasite is intra-nuclear and is extending pseudopodia out of the nucleus, but it may be 
that the nucleus is merely surrounded by the parasite, which occupies this position for some 
purpose of nutrition. In the case of the Plasmodmm of birds a similar position in contact 
with the nucleus is often observed. At this stage in films stained by Giemsa stain, the parasite 
is seen surrounding the nucleus. The protoplasm stains a faint blue, and there may be one 
or more cbromatin granules arranged at varying places in the body of the parasite. Pigment 
is present in the shape of fine granules, which are frequently clustered together into several 
groups at difi'erent spots. Such forms as are represented in Plate XII., figs. 5, 9, 10, may 
be a group of several distinct parasites or one amceboid parasite surrounding the nucleus. The 
presence of the parasites in contact with the nucleus has little effect on this structure, apart 
from a slight irregularity in its contour. In staining reaction there is little difference from 
the uninfected red cells. In the fresh blood the forms associated with the nucleus show very 
slight amoeboid movements. In no case was so great a movement as the total withdrawal of 
a single pseudopodium observed. 
.\s has been mentioned above, some of these forms have several chromatin granules. Other 
forms are met with which are spherical and lying away from the nucleus. Such a form 
is represented in Plate XII., fig. II. It has six chromatin dots, and the body of the parasite 
appears to be undergoing segmentation into six merozoites. These forms are evidently 
schizonts. Apart from these amoeboid forms, which appear to become ultimately schizonts, are 
the gametocytes, male and female. The male gametocytes are pale staining bodies (figs. 2,11) 
of oval contour. They occupy one end of the red cell without altering the shape of the cell or 
displacing its nucleus. Granules of fine pigment are scattered through the body of the parasite, 
or, more commonly, arranged in clusters at the periphery. The nucleus is a group of chromatin 
granules at the centre of the gametocyte. The size of the gametocyte may be 8'5p by 5'5/i. 
Usually it is a little smaller than this. The female gametocyte differs little from the male except 
in the density of its protoplasm, which consequently stains a deeper blue (figs. 6, 7, 12). In 
gametocytes which have been deeply stained, dark red masses of a substance resembling the 
material of the host-cell nucleus appear on the surface of the parasites. These dark red 
staining areas occur at the spot where the pigment grains are clustered into heaps which are 
quite obscured by the presence of this substance. It is only present in deep staining, and 
what its nature is cannot be stated unless it be merely a deposit of red stain around the grains 
of pigment (Plate XII., figs. 3, 6, 7, 12). It must not be confused with the several chromatin 
clusters seen in the schizonts. In the fresh blood the gametocytes are verj' sluggish 
and show little movement. In vain was search made for microgamelic formation in the fresh 
blood, but in some of the stained films, forms which were undoubtedly microgametes were 
encountered. A microgamete is represented in fig. 14. In the same film, spherical extra- 
corpuscular male and female gametocytes were met with, so that, as these films were 
made from a lizard some two hours after it was killed, it is possible that microganietes 
Plasmodium 
in a lizard 
Morphology of 
the parasite 
