TKYPANOSOMIASIS IN THE ANOLO-EOYI'TIAN SUDAN 119 



The trypanosome coucerued is a small oue. (Plate XIV., Fig. k.) It is not very active Morphology of 

 in fresh films, and I have never seen one traverse the whole field of the microscope. The 

 motion is undulating, combined with a vigorous lashing to and fro of the anterior part of the 

 body, which tapers to a very tiny flagellum. Rippling, and what may be termed spreading, 

 movements have also been observed. The parasite advances usually with the narrow end in 

 front, but this motion is often i-eversed, and I have seen one move a considerable distance, 

 pushing aside the erythrocytes with its blunt posterior end. A fact which is very noticeable 

 is that the trypanosome tends to adhere to the red blood corpuscles. Even in a thin field 

 this is seen, the parasite seeming to take a delight in butting and boring at the erythrocytes. 

 Frequently it gets beneath them and is lost to view, the agitation it produces being the only 

 clue to its presence. Having studied this trypanosome, both in the living and stained 

 condition, and having conducted a few inoculation experinieiits on laboratory animals [ride 

 infra), I became convinced that this was either a new and undescribed trypanosome, or was 

 identical with the parasite of cattle found by Bruce, Nabarro, and Greig on the shores of the 

 Victoria Nyanza in Uganda. Stained specimens were sent to the Liverpool School of 

 Tropical Medicine, but I learn that unfortunately the stain had faded and could not be 

 repeated with success. In the meantime I had sent unstained films to Professor Laveran,* to 

 whom I am much indebted for his kindly interest, and who, in the Proceedings of the 



Biological Society of Paris of 24tli 



• 



February, describes the stained try- 

 panosome, which he regards, provided 

 further experiments prove it to be 



^^^1 peculiar to cattle, as a new species, and 



■f': 



^ 



,J5*^, which, on account of its small size, he 



'is^'' has named 1\ nainiiii, i.e., the dwarf 



trypanosome. 



His interesting description of these 

 parasites is as follows : — 



" The trypanosomes measure 10 

 ^j,^' j^^- ^j^ to 14 ^ in length, by i to 2 fi in 



breadth. Their structure is that of the 

 flagellates of the genus trypanosoma, 

 although, contrary to the rule, the 

 protoplasm is prolonged on the anterior 

 part in such a way that there is no 

 free part of the flagellum, or the free 

 part of the flagellum is extremely 

 short. The undulating membrane is very straight, and in consequence but little apparent. 

 The posterior extremity is conical, not drawn out, and in other resjiects varies somewhat. 

 The oval nucleus is situated near the centre of the body of the parasite. The rounded 

 centrosome, rather large, occupies a position close to the posterior extremity. The 

 protoplasm is homogeneous without granules. 



"Some forms a little longer than the others show two centrost)nics and a flagellum, 

 divided to a greater or lesser exti'ut, proceeding from the ceutrosomic insertion." 



Fig. 6.5. —T. Nanc'm. x 17.50 di.ini. 



* Compt. reud. Soc. Biol., Paris, 1906, Feb. 24th. 



