46 



Sir D. Bruce and others. 



and appearance of the pigment, which is not scattered throughout the 

 parasite, but is collected in a single mass, and is pale yellow in colour 

 (Plate 5). Schuffner's dots have never been seen, but in some instances 

 (Plate 4, figs. 5, 6, and 7) pseudopodia were seen with a scar in the red cell 

 recalling the formation of Maurer's dots in Zaverania malarice of man. The 

 forms of trophozoite shown in Plate 4, figs. 6 to 12, are, so far as our 

 experience goes, unique, first in the dense blue-staining (Giemsa) of the 

 protoplasm, and, secondly, the great enlargement and marked paleness of 

 the red cell with absence of Schuffner's dots, and the intense concentration 

 of the portion of red cell in the food vacuole. This concentration, as will be 

 seen in the figures, proceeds until nothing is left but a block of gamboge- 

 yellow pigment (Plate 4, figs. 14 to 16). The distended red cells are so 

 delicate that they are frequently ruptured in making the film, as is shown 

 in Plate 5, figs. 7 and 8. The great size of the parasite is also remarkable, 

 some of the free merozoites measuring 4 microns by 3o microns, the exact 

 size of a normal red cell of the antelope. A full grown schizont, before 

 cleavage of the protoplasm, measures 10 microns by 10 microns (Plate 4, 

 fig. 19). 



The presence in the gametocytes of numerous deeply staining chromatin 

 granules, in addition to the faintly stained nucleus, is also remarkable. The 

 arrangement of these granules in some of the merozoites suggests a relation- 

 ship with the Hcemoflagcllata (Plate 4, figs. 3 and 23) ; and in this connec- 

 tion it may be mentioned that one duiker was also naturally infected with 

 a trypanosome of non-pathogenic type, which it is proposed to describe in a 

 future paper. 



In films taken some days and even months after the acute attack, the 

 forms shown in Plate 5, figs. 12 to 16, are common, and but for the presence 

 of pigment might be mistaken for faintly stained leucocytes. As these are 

 the most persistent forms (macrogametocytes), attention is directed to them, 

 as they are the forms likely to be met with in examination of blood films of 

 antelope taken in the field. 



One of the small duikers appeared out of condition for a few days, while 

 the parasites were numerous in the blood : coat staring, nose hot and dry ; 

 but it soon regained its health, and has remained healthy since. The other 

 duiker was apparently not at all affected, although a few parasites could be 

 found in its blood for some six months. 



The duiker which was chronically infected was captured in the low 

 country near the Lake shore, and was about three months old when brought 

 to Kasu Hill, where a few weeks later a few parasites were found in its 

 blood. It is therefore probable that it was infected before capture. Whereas 



