26 Sir D. Bruce and Capts. Hamerton and Bateman. [Sept. 18, 



It is generally found close to the vacuole ; sometimes it lies close to the 

 nucleus, but it is nearly always posterior to the latter structure (Smedley). 



Flagellum. — Takes a tortuous course along the free border of the undulating 

 membrane, and projects for a short distance from the anterior extremity 

 (Smedley). 



Undulating Membrane. — No detailed description given. 

 Colonies or Aggregates. — Most of the flagella are directed in an outward 

 direction. It is rare to find colonies of a large size (Smedley). 



Measurements of the Cultural Forms of Trypanosoma brucei. 



Length, including flagellum, 18 to 23 x 2 - 5 to 3'5 microns. Length of free 

 flagellum, 3 to 5 microns. Diameter of vacuoles, 1 to 2 microns. The adult 

 parasitic forms of Trypanosoma brucei measure, in the blood of rats, 26 to 27 

 xl'5 to 2 - 5 microns (Laveran and Mesnil) (Smedley). 



Cultural Characters of Trypanosoma evansi. 



A. Living, unstained. 



Size. — The body of one large individual measured 21 microns, while the 

 flagellum was 28 microns in length. 



Shape. — The slender fusiform body terminates at one end in a delicate 

 flagellum. The posterior end, especially when blunt, showed a rod-like tip 

 or stylet, which varied from 2 to 4 or even 6 microns in length. As the 

 cultures aged, pear-shaped or spherical, highly granular, involution forms 

 appeared. In the former type, measuring about 3 by 5 microns, the end was 

 often provided with a flagellum, 10 to 15 microns long, which still showed 

 a slow lashing movement, though the cell itself was motionless. The 

 spherical forms varied from 4 to 9 microns in diameter, were granular, and 

 often showed a remnant of the flagellum as a short, stiff, motionless whip. 

 These involution forms, as in the case of Trypanosoma lewisi and Trypano- 

 soma brucei, eventually gathered into large groups or masses, which at times, 

 filled the field of an immersion lens. Later on, the round bodies broke up 

 into masses of very minute granules. 



Contents of Cell. — Presence and peculiar arrangement of granules within 

 the cells, and a distinct yellowish or greenish colour of the granules and of 

 the contents. Large numbers of small granules or globules, which vary from 

 - 3 to - 5 micron in diameter. These globules, as well as the contents of the 

 cell, possess a decided yellowish or greenish colour, and appearance quite 

 unlike that of either Trypanosoma lewisi or Trypanosoma brucei. The 

 globules are usually massed in the anterior- third of the cells — that is, at the 



