NAGANA-FOCI IN GEEMAN EAST AFEICA. 261 



above. On p. 145, there is a comparative diagnosis of 

 Gl. morsitans, " tachinoides," and " tabaniformis." 



Notes on the distribution of " Surra " and Tsetse-flies in 

 German East Africa. 



[Translation,] " Since the labours of Professor Koch 

 innumerable cases of Surra have been observetl here, 

 above all by Veterinary-Surgeon Schmidt ; in addition to 

 this small herds of cattle have been driven, by way of 

 experiment, along certain roads, in order to discover by 

 what roads cattle can be transported without danger of 

 contracting the disease. The results are shown on the 

 appended map (Tafel II), on which the red spots indicate 

 the places where Surra infection has been positiA^ely 

 demonstrated or where it is strongly suspected to exist, 

 while the red streaks show the roads on which animals 

 were infected. It looks quite distressing to find the very 

 foot of the Usambara Mountains, in the neighbourhood 

 of the cofiee plantations, so thickly beset with Surra-foci, 

 but we must consider that that was the place where many 

 cases came under observation, and that consequently it is 

 probable that in future many a centre of infection will 

 also be found in the remainder of the territory. On the 

 whole, river-lowlands with high reed-grass seem to be 

 exceptionally dangerous, just as in South Africa the 

 plains of the Limpopo and Zambesi are especially dreaded. 



" Particularly at the foot of East Usambara have 

 cases of infection frequently been shown to have occurred ; 

 many a head of cattle kept on the plantations, which had 

 formerly been driven through these districts, died froui 

 Surra. The following localities are especially suspicious : 

 Bondei Land, Kwa Maromo, the neighbourhood of Lewa, 

 and also Mombo, Masinde, the eastern foot of the Pare 

 Mountains and the borders of Lake Jipe. The mountains 

 of West Usambara, the localities Korogwe and Massigi, 

 as well as Lake Manga are certainly free from the disease. 

 The Masai, who are well-known as the best herdsmen, 

 always ascribe the deaths of cattle to the fact of their 

 having eaten reed-grass ; but it is to be supposed that it 

 is precisely this grass that harbours the Tsetse-fly, which 

 occasions the infection. The fly dreaded by the Masai 

 under the name ' Ndorobbo ' is still unknown ; it appears, 

 however, from the description to be more probably a 



