GLOSSINA INVESTIGATIONS IN NYASALAND. 263 



A further series of flies following at one's heels in the early morning and evening 

 and settling on the ground from time to time, but not attempting to bite, have been 

 secured ; all have been males. As has been repeatedly noted by other observers, 

 male flies settle sometimes on one's back and do not attempt to bite, an occurrence 

 in my experience more frequent in the heat of the day. The interpretation of this 

 habit is, I believe, that the ground, which is then so hot as to be unpleasant even 

 to the feet protected by thick boots, is too scorching for the flies, which then avail 

 themselves of the coolest situation convenient. I have endeavoured to obtain some 

 evidence as to whether such flies really are on the look out for females only, by causing 

 boys to carry on their backs as they walked through fly country newly emerged 

 female flies gummed by the legs on brown paper, but no results were obtained, 

 though as the male seizes the female while on the wing, no negative inference can 

 be drawn from the experiment. 



Observations on Glossina brevipalpis. 



This species was found in February to occur in a very limited area in the centre 

 of the Lingadzi estate, which is situated on either bank of the river of that name, 

 about eight miles from Lake Nyasa. The estate is surrounded on three sides by 

 dense bush, but towards the east is more open, consisting of thin woods interspersed 

 with dambos. It was at one time used as a cattle station, but the enterprise was 

 abandoned some years ago owing to the advent of morsitans, and now a limited 

 portion only, some ten or twelve acres, is under cultivation for fruit. 



G. brevipalpis to the number of ten to fifteen, all males, were taken night after 

 night at about dusk in the fruit garden within an area of about fifty square yards, 

 mostly along a path running through it from the bank of the river. The fruit trees 

 growing at the spot were bananas, mangoes, and citrus fruits ; three large indigenous 

 trees, one evidently allied to our plane tree, being the only others therein. The area 

 w^as devoid of weeds and undergrowth, except for a broad belt of coarse high grass 

 growing in the mud of the river bank. The soil was a well-drained rich black humus, 

 except along the path, where, owing to the lighter portions having been washed away, 

 some sand was in evidence. 



A systematic and very careful attempt was made day after day to discover why 

 the fly was present and in so limited a space, but no light was obtained on the 

 question. As the rains were on there was no difficulty in examining the spoor of 

 animals passing through the area, and this was done for a fortnight. The foot-prints 

 of duiker antelope were found very commonly, and on one occasion those of a kudu, 

 and so far as could be ascertained these were the only large animals which passed 

 through it during this time. Toads occurred in some numbers, and an attempt was 

 made by keeping some in captivity to ascertain if the flies ever fed on them. They 

 did not do so, but were gradually caught and eaten by the toads. An endeavour 

 was made also to ascertain if the flies would feed on fruit and fruit juices, but no 

 results were obtained. 



No female flies at all were taken among a total of 119 flies, neither were any pupae 

 found, though sought for in every conceivable situation — at the bases of all the trees, 

 high up in the forks of the larger trees, in the debris around the bananas, in the 



