308 SEEOOT FLIES IN SUDAK 



the bites — such bleeding as, for instance, according to Sir H. M. 

 Stanley [45], results from the bites of a large horse-fly, called 

 Mabunga by the natives, near Rosako, in Ukwere, about twenty 

 miles inland from Bagamoyo. " This fly," writes Stanley, 

 " along with a score of others, attacked iny grey horse, and 

 bit it so severely in the legs that they appeared as if bathed 

 in blood."* The explorer's men " unanimously stated that its 

 bite was fatal to horses as well as to donkeys." In " The Nile 

 Tributaries of Abyssinia" (London: Macraillan and Co., 1867), 

 the late Sir Samuel W, Baker, writing of the country between 

 the Settite and Atbara Rivers, describes and figures a " Seroot 

 fly" (pp. 184-185), which he states (p. 184) is the species "that 

 drives the camels from the country " ; from the figure and 

 description it is evident that this insect is a horse-fly belonging 

 to the genus Pangonia, and not a Glossina. Further on (p. 196), 

 a remarkable description is given of an instance in which swarms 

 of Seroot flies rendered it impossible to take possession of a 

 giraffe which had been shot. Sir Samuel Baker writes : " The 

 Seroot-fly was in swarms about the carcase, thousands were 

 buzzing about our ears and biting like bull-dogs ; the blood was 

 streaming from our necks, and, as I wore no sleeves, my naked 

 arms suffered terribly. I never saw such an extraordinary 

 sight ; although we had killed our giraffe, we could not take 

 possession ; it was no wonder that camels and all domestic 

 animals were killed by this horrible plague, the only wonder was 

 the pos.sibility of wild animals resisting the attack. The long 

 tails of the giraffes are admirable fly-whippers, but they would 

 be of little service against such a determined and blood-thirsty 

 enemy as the Seroot." Subsequently (p. 210) the author men- 

 tions herds of game as retreating from the south before the 

 attacks of the Seroot. On the Blue and White Niles several 

 species of horse-flies, belonging to the genera Tahanus and 

 Pangonia, are known to Europeans under the comprehensive 

 name Seroot ; all are gi-eedy blood-suckers, but it would lead us 

 too far from the question at issue to pur.sue the subject further. 

 It is hoped, however, that enough has been said to demonstrate 

 the advisability of 'determining once for all, by a series of practi- 

 cal experiments, whether the various African species of Tabanidne, 

 as also those near allies of the Tsetse belonging to Stomnxys or 

 Lyperosia can, under any circumstances, become the carriers of 

 the Trypano.?ome of Nagana, or possibly of some other closely 

 related hfematozoon. 



* There is no need, however, to go to Central Africa in order to see 

 horses' legs streaming with blood from the attacks of Tabanidse, since 

 this can be observed in Switzerland and Italy. That African cattle can 

 withstand the loss of a considerable quantity of blood without succumbing 

 is proved by the well-known habit of the Masai of bleeding their cattle to 

 the point of faintness for the sake of drinking the blood ; in this case the 

 cattle recover after bleeding lias terminated. 



