380 ' C. F. M. SWYNNERTON. 



than my animal or animals that marched second, but that relative and perhaps 

 nearly complete protection would be afforded I am convinced. 



I have heard it stated at second hand from a man who had had some experience 

 of running cattle through fly that it was chiefly the outside animals of a mob that 

 were attacked. It may be possible to prevent even this. 



I failed to carry out any experiments in the matter of spraying or wiping animals 

 with paraffin or other deterrent liquids, though it had been my intention to do so. 

 Against brevipalpis the animals' lower surface should be sprayed. 



When biting flies are abundant it is a common experience to have them attack 

 the cattle at once on their emerging from an arsenical dip. An internal tsetsefuge 

 might, however, be experimented for and be used where the number of cattle was not 

 too large for treatment. During our first epizootic of African Coast fever, in 1900, 

 when I was already losing stock seriously, I tried dosing the surviving cattle each 

 morning with a double handful each of garlic, crushed and given in a bottle of water — 

 as we had then no dipping tanks. I am inclined to attribute the fact that T saved 

 a much larger percentage of our small herd than did any of our neighbours (who lost 

 nearly ever\i;hing) in part to the deterrent effect of the garlic on the ticks. I do 

 not know its effect in relation to biting flies, but it might be tested, and if it were 

 successful, garlic-eating might become a useful if obnoxious habit in sleeping- 

 sickness areas. 



Clearing Measures. 



(1). Clearing by cutting down. WTiere not followed up, the good effect of this 

 measure must be very transient, for the stumps quickly produce coppice of a tjipe 

 that is specially liked by pallidipes (PI. , fig. 46) — or, under shade, by brevipalpis. 

 Where, on the other hand, clearing by cutting down is followed by very late annual 

 burning, its effect, very generally speaking, is likely, when the grass is sufficient, to 

 last as long as the late burning is kept up. It is said that a large proportion of 

 JJapaea cut down during the rainy season does not grow again. I have no observa- 

 tion on this myself beyond the fact that Uapaca trees are more easily killed in native 

 gardens by burning than are various other trees. The reaction of each of om* 

 commoner tree species to the cheaper methods of clearing would be worth ascertaining 

 by special experiments. 



(2). Clearing hj ar senile. Experiments that I carried out on pieces of wooding 

 selected as representing an average of a type that was well infested with brevipalpis 

 did not suggest that the clearing by arsenite of such continuous Bracliystegia bush, 

 as fills the " Oblong " and runs north to the British border past Spungabera would 

 necessarily run to a prohibitive figure for this class of work, though the full strength 

 to be used remains uncertain. Naturally the clearing of great areas is in any case 

 certain to be expensive. 



Superintendence and transport of water, etc., have to be considered. WMle 

 native police might superintend the actual working groups, general supervision by a 

 European would be necessary both for the efficient organization of the water trans- 

 port and of the work generally, and because it would be unsafe to leave large quanti- 

 ties of poison in the sole care of native police. The best effects from poisoning would 

 probably be obtained when the sap is up, that is in the spring and summer. Water 



