1896.1 MICROSCOPICAL JOURNAL. 395 



ecchymoses in various regions, and congestion and fatty 

 degeneration of many organs. The tsetse fly {Glossina 

 morsitans, Westwood), is about 11 mm. or seven six- 

 teentlis of an inch in length, and Las transparent wings 

 about 10 mm. long. On the upper surface of the abdomen 

 there is a longitudinal yellow line with four yellow lines 

 crossing it at right angles. In 1894 Surgeon-Major 

 David Bruce, A. M. S., discovered that the blood of ani- 

 mals suffering from the tsetse fly disease invariably con- 

 tained a heraatozoon which had not been previously 

 observed in Africa, but which he considers to be either 

 identical with or closely resembling the Trypanosoma 

 Eva7isi found in surra, a disease occurring in India and 

 Burmah ; surra, however, as known in India, does not 

 affect cattle. In fresh blood these hematozoa are seen 

 as actively moving transparent elongated bodies, in 

 thickness about a quarter of the diameter of a red cor- 

 puscle, and in length about two or three times the dia- 

 meter of a corpuscle. One end is bluntly pointed and 

 the other is prolonged into a very fine lash, which is in 

 constant whiplike motion; the body is cylindrical and has 

 a transparent, delicate, longitudinal membrane or fin, 

 which is also in constant motion. Surgeon-Major Bruce 

 believes that the fly acts only as a carrier of these mi- 

 crobes from infected to susceptible animals, and does 

 not cause the disease by means of any poison elaborated 

 by itself. A limited number of flies may bite a sus- 

 ceptible animal over and over again without producing 

 any ill effect, but, -^hen a horse is taken into the fly 

 country for even a few hours, or when numerous suc- 

 cessive relays of flies freshly caught in the fly country 

 and brought into a healthy district are made to settle 

 on an animal there, the disease is almost inevitably set 

 up. Five flies kept in a cage with muslin sides were 

 allowed to bite the shaved abdomen of a small dog every 

 two days from September 25th to November 28th, but 



