20 



J. E. L. JOHNSTON. 



in 1913. There was also a marked contrast between the conditions during my first 

 stay at Kaduna and my second, a few weeks later, after there had been some heavy 

 rains. 



I could obtain no history of any illness amongst the many horses in Kaduna, and 

 tsetse-flies were practically unknown. 



Birnawa. 



I was told that tsetses abounded along a small stream half-way between Kaduna 

 Bridge and the village of Birnawa, but although I visited this stream and another 

 flowing close to the village, and the thick " kurmi," or bush, on the banks of each on 

 three successive days, I found none at all. The streams were almost dry, and con- 

 sisted chiefly of a chain of pools, from which I obtained numerous mosquito larvae,^ 

 all of which proved to be Culiciomyia nebulosa. 



AfakaJIdm.) 



Ubassi .'^ 

 (Idm.) ! 



'o\/V^^5 



> Bu0a/ 



/ \ TOW 



Kujama 



^'Kudemsa 

 (12 m.) 



Fig. 1. Sketch-map of the country round Kaduna Bridge. The small numbered 



circles indicate the positions of the various herds examined ; the mileage 



in brackets is the approximate distance from Kaduna Bridge. 



There were two small herds of cattle near Birnawa (see fig. 1, nos. 1 and 2) and I 

 took a few blood films from each herd. The herdsmen told me that flies that troubled 

 the cattle had been plentiful in the kurmi sLx weeks earlier {i.e., during the wet weather 

 in June), but that there were none now, and I could obtain no history of any sickness. 

 However, two of the first herd showed trypanosomes, and one of the second 

 piroplasmata 



