470 Col. Sir D. Bruce and others. Trypanosome [May 13, 



Distribution in Uganda. 



Cattle suffering from Trypanosoma pecorum were sent to the Sleeping 

 Sickness Commission's laboratory at Mpumu from Entebbe, Kampala, 

 Namukekera, Kabula Muliro, and Mabira. It is probably widely distributed 

 throughout Uganda. It was also found in a horse which had arrived in 

 Nairobi, British East Africa, from Abyssinia. The Commission is indebted 

 to Mr. Stordy, Principal Veterinary Officer, for the opportunity of studying 

 this trypanosome. It is not known where the horse became infected, but it 

 must have been at some point between Nairobi and the Abyssinian border. 



Morphology of Trypanosoma pecorum. 



A. Living, Unstained. 



This trypanosome, when observed in a preparation of fresh blood, is seen 

 to remain at or near the same spot in the field, that is to say, it is non- 

 translatory. It is, however, active and restless, the body quivering rapidly, 

 and the undulating membrane and flagellum keeping up a constant vibratory 

 motion. As a rule, it moves with the flagellar end in front. The contents of 

 the cell are homogeneous, except for a vacuole at the posterior extremity. 



A marked characteristic of this species is that it exhibits alternating 

 periods of quiescence and activity. When quiescent it is usually invisible, 

 as it lias a habit of burying itself under small collections of red blood 

 corpuscles. 



B. Fixed and Stained. 



Metliod of Staining. — Giemsa's method, as described in a former paper,* 

 was used. 



Length. — Tlie same method of measuring was used as described in the same 

 paper (p. 17). 



Breadth. — Without the undulating membrane the average is about 

 2 microns, with the membrane about 3 microns. 



Shape. — Tliis trypanosome when stained is short and stout in form. The 

 posterior extremity is blunt, or rounded, or pointed and angular. The 

 anterior end is narrower. The undulating membrane is fairly well developed, 

 more so, perhaps, than in T'rypanosoma nanum. The flagellum arises near 

 llio micronucleus, and passes along the edge of the undulating membrane. 

 Tliere is no free flagellum. 



Contents of Cell. — (Jcncrally homogeneous. Sometimes granules are seen 

 which take on a chromatin stain, and are situated anterior to the nucleus. 



Nucleus. — Is oval in shnpc, and situated about the middle of the Ijody. 

 * ' ]{oy. Soc. Troc.,' B, vol. 81, ]>. IG. 



