DOOG AND BALAAD ON WEBI SHEBELI. 307 



blood of the diseased camels. Dr. Radford expresses the opinion 

 that the hsematozoon of Tsetse-fly disease "is in all probability to 

 be found in many species of Diptera," but he advances no further 

 arguments in support of this view, which, in so far as it refers to 

 the normal conveyance of the parasite, is, as already pointed out, 

 a priori improbable. With regard to the alleged effects of the 

 bites of Tabanid?e upon camels, however, there is some further 

 evidence, though in this case it is quite possible that the real 

 culprit is Glossina longipennis, which is of about the same length 

 as the smaller fly referred to. Colonel Swayne, writing to the 

 Secretary of the Zoological Society in 1894, said : "I send you 

 three specimens of ' Doog ' (a large fly) and three specimens of 

 ' Balaad ' (a small fly). ... I was very much pestered by ' Doog ' 

 on my way through Ogaden to the Web be Shebeyli, in Somaliland. 

 They swarmed on my camels, constantly drawing blood. The 

 other fly, ' Balaad,' which looks not unlike the common house-fly, 

 is far the worst fly on the Webbe ; a valuable camel, on which I 

 caught three or four two months ago is now dying, and the 

 Somalis say that this is due to the bites of ' Balaad.' If there are 

 many of them they kill horses and camels, and the Somalis will 

 not have their live stock grazing where ' Doog ' and ' Balaad ' are 

 found." * On the other hand, the conclusion which might be 

 drawn from Colonel Swayne's statements is traversed by others 

 contained in a Report (dated May 26, 1891) from the officer in 

 charge of what was then the Imperial British East Africa Com- 

 pany's Station at Lamu. According to this document, which 

 accompanied specimens of Tsetse-flies and Tabanidie sent to the 

 British Museum for determination, the bites of horse-flies inflicted 

 upon domestic animals do not cause " any kind of blood-poisoning 

 like those of the Tsetse," although it is stated that some of the 

 natives declare that they do. The Report observes that the bite 

 of the Tabanidse "is extremely sharp, and, though causing 

 comparatively little irritation, produces much swelling of the 

 surrounding parts." The writer adds : " Both cattle and donkeys 

 bleed a good deal from the puncture, and the Germans tell me 

 that in some cases their cattle bled to death, it being impossible 

 to stop the bleeding, although they tried acids, etc." The latter 

 statement suggests the possibility that, in some cases at any 

 rate, animals said to have been killed by the bites of flies other 

 than Tsetse, may really have died from haemorrhage caused by 



* Two species seem here to be distinguished by the Somalis, but the 

 specimens sent by Colonel Swayne included examples of three : of the 

 three flies representing " Doog," two proved to belong to a new species 

 subsequently described by the author under the name Pangonia tricolor 

 {nom. preocc. = P. beckeri, Bezzi), while the third specimen belonged to 

 another species of Pangonia, but was too much damaged for, determination. 

 The three specimens representing "Balaad" were examples of a small 

 Tabanid, somewhat resembling Hxmatopota in form, but with clear wings ; 

 these specimens were also too much damaged to determine. 



