151 



which permitted free ventilation and evaporation. But a tsetse or 

 other biting fly could get through these spaces. To prevent this a 

 layer of coarse mosquito netting was sewn on the surface of the knitted 

 string, so that a fly found its proboscis too short to reach the skin. As 

 this fly-proof helmet lies close to the head, it is possible to creep or 

 push through thorny scrub without any danger of being held up. Of 

 course, as a protection against the sun, a large felt or terai hat must 

 be worn over the helmet, but this can easily be arranged. 



" When cycling through fly-country, especially on a motor-cycle, 

 the tsetse-flies often attack in great numbers, and very viciously. 

 Sometimes they follow like a swarm of angry bees, and it is necessary 

 to stop now and then and break off a branch in order by its aid to drive 

 them away. On these occasions the cyclist is liable to be severely 

 bitten unless he is adequately protected. A net is of little use, but 

 the above-described headgear, with the addition of a pair of motor- 

 goggles, gives excellent protection for the face and neck. 



" It is necessary to see that there is no undefended space between 

 the goggles and the helmet. The only parts exposed are the nose and 

 mouth ; if a fly attacks here it can be blown away. 



" To protect the hands, fingerless gloves with khaki gauntlets were 

 made in the same way, except that the palm was made of leather, 

 with a hole for the forefinger to go through." 



The failure of external applications to the skin, with the exception 

 of beechwood creosote and beechwood oil, to afford protection from 

 the bites of Tsetse-flies, and a suggestion as to the possibly protective 

 effect of eating garlic have been noted above (see pp. 149, 150). 



DESTRUCTION OF BIG GAME. This method of combating Tsetse- 

 flies, which is advocated by certain writers, seems a radical one, but 

 at present none can tell whether it would prove really effective. As 

 we have already shown, the question is not yet settled, and what is 

 actually needed is experiments scientifically planned, and carried out 

 with every precaution necessary to ensure accurate results. 



The experimental abolition of the .wild fauna might, for instance, be 

 tried in a definite region. It would thus be possible to determine the 

 degree of influence exerted by big game on the bionomics of the fly, 

 on its infectivity, and subsequently on the health of human beings and 

 domestic animals. 



In this connection some pertinent recommendations are contained 

 in a report by Sir Arnold Theiler (147), published in 1917. It is stated 

 that an investigation had been carried out in Zululand, with the object 

 of determining the extent of infection with trypanosomiasis, and with 

 particular reference to the spread of the disease and the best means 

 of prevention and eradication. The conclusions reached were that 

 wandering game is responsible for primary outbreaks of the disease ; 

 and that Glossina does not travel from the original fly-belt unless cover 

 is continuous or it is in company with game. In the absence of Tsetse 

 it was considered unlikely that outbreaks of nagana could originate 

 from recovered or partly recovered cattle, or from game localised in 

 the cattle-grazing area. 



As a result of the investigations, certain recommendations had been 

 made with a view to localising game so far as possible, and for its 

 efficient protection in the reserves. These include the issue of permits 

 to Europeans and natives living in nagana areas, authorising them to 

 destroy wandering game ; these permits to be valid during the summer 

 months as well as during the open season. The destruction of game in 



