248 WANDOEOBO-FLY OF WADSCHAGGA. 



occurred. In vain have we also looked for the puncture 

 of the insect on the genitals of the donkeys, in which 

 region according to the declarations of the natives it 

 ought to be found ; all that we are able to see, and this 

 invariably, was a sometimes slower, sometimes quicker 

 swelling-up of the mucous membranes, of the upper orbits, 

 lips, nostrils, and jaws accompanied by greater swelling 

 of the genitalia. The animals finally had a very high 

 body temperature, with quickened breathing, and died of 

 suffocation owing to difficulties in respiration. At that 

 time we also were of the opinion that we had only lost our 

 donkeys in the territories of the Tsetse-fly, and that the 

 latter had occasioned the phenomena of poisoning. To-day, 

 on the contrary, we would incline to the view, that we are 

 confronted with a phenomenon analogous to what is found 

 in the case of horse-sickness in South Africaj and that the 

 sickness represents a special form of infection with the 

 greater probability, since the South African disease already 

 appears to be recognised as such. Definite gi'ounds for 

 believing in insects (bestimmte Anhaltspunkte fur InseJden) 

 have not been discovered, and the imported Muscat 

 donkeys were attacked soonest and in the largest per- 

 centage. According to the statement of the natives, 

 moreover, similar symptoms of disease sometimes appear 

 in human beings. At the coast it had already been pro- 

 phesied that we should lose our donkeys on the steppe, 

 and we therefore searched for the Tsetse-fly so zealously, 

 that it would scarcely have escaped us if we had really 

 entered its territory. That the Wadschagga designate 

 a small fly by the name Wandorobo appears to me to be 

 probable, but the question is whether we are here dealing 

 with the Tsetse-fly. The districts in which we lost our 

 baggage-donkeys cannot be called free from fever ; the 

 Natron Valley, where the sickness first appeared, is in 

 many places swampy, and the neighbourhood of Kibwesi, 

 which is characterised as especially unfavourable for the 

 escape of the animals, would doubtless exhibit malaria. 

 As Professor Koch has shown, punctures by insects have 

 an importance in connection with malarial infection in so 

 far as blood-sucking insects carry contagious matter into 

 the blood. It may well be doubted whether it is the 

 Wandorobo-fly alone that is able to transport the malaria 



