147 



in time, spread down the river. The greyish white pupae, 4 milh- 

 metres long, were abundant on dried twigs, stalks, etc., which were 

 either standing or had stood in water. Where the plants were standing 

 in water no adult flies emerged, and this was confirmed in the labora- 

 tory. All the dead cattle exhibited reddish spots hke flea-bites, 

 which were very numerous near the genitalia and on the inner side 

 of the legs. The sick animals he down most of the time, appear to 

 be exhausted and have a weak, rapid pulse. Later they become 

 drowsy and then die. The neck is swollen from chest to throat, and 

 on dissection this part was found saturated with a clear fluid, probably 

 due to extravasation. Internal haemorrhages were noticed. 

 No infectious causative agent has been discovered hitherto, and 

 death was probably due to poison from the fly's sahvary glands. The 

 flies can be captured by rimning the hp of a bottle along the belly 

 of the animal, when they will fall into the bottle. They can also be 

 foimd with case on the banks of the river, especially on the under-side 

 of leaves, etc. 



Nothing definite can be said as regards control. So far as is known, 

 swarming lasts from 2 to 3 weeks, about the end of April and the 

 beginning of May. A second generation is said to swarm in August. 

 Pastures more than IJ miles distant from the banks are only infested 

 when the wind blows toward them. In cool weather, which hinders 

 the emergence of the adult fly, the cattle may be put out to graze. 

 If grazing is imperative in warm weather, it should be done at night. 

 It is advisable to clear away vegetation, including meadow-grass, 

 near the banks, preferably in the autumn. 



Jack (R. W.). Illustrations of Natural Forest in relation to Tsetse- 

 Fly, — Rhodesia Ayrk. JL, Salisbiiry, xi, no. 4., April 1914, pp. 

 548-57G, 12 figs., 1 sketch map. 



One of the objects of the author is to show, by means of photographs, 

 the kind of comitry in which (ilossina morsitans is, or is not, found, 

 and to endeavour to account for the exceedingly local distribution 

 of the fly. This tsetse-ily rc(|uircs adequate shade, is a slow breeder 

 and of gregarious habits, and there is reason to beUeve that it draws at 

 least the greater part of its nourishment from the larger mammals, 

 and that therefore, other conditions being favourable, it is likely 

 to frequent parts of the country where such animals are found . Further, 

 a thoroughlv dry situation appears to be all that is necessary for the 

 welfare of the pupae, though, as a matter of fact, the bases of large 

 trees appear to be the favourite situations selected by the female 

 for the extrusion of the maggots. 



The author does not agi-ee with the statement of early writers as 

 to the sharp delimitation of the fly-belts. Fly is found in the wet 

 season in parts of the forest from which it is altogether absent in the 

 dry, and the writer says that he has never encountered fly suddenly 

 in abundance, unless there were well-marked changes in the forest 

 or country to explain the fact, and that where the edge of a fly-belt 

 appears to l^e sharply defined it is in every case due to some change 

 in the surroundings. The greater part of the surface of Rhodesia 

 is covered with bush of some description. The sparsely covered 



