RESEARCH IN BRITISH WEST AFRICA. 201 
is crossed, Particularly to be noticed on this day’s march was the large number 
of Borassus palms, which so far had hardly figured in the vegetation. Tsetse 
were seen at Amodi, Panchang, and Porli, and all seemed to be Glossina 
morsitans, although, from the nature of the country and the close proximity to 
the creek, one would rather expect to find Glossina palpalis. One specimen 
caught on the pony at Panchang at 8.15 a.m. was G. morsitans, as also were 
others caught at Tento in the stable at 12.30 p.m. so that in all probability the 
others were also morsitans. Tabanus taeniola was also caught in the stable at 
11.30 a.m. 
Between Tento and Ker Sidi there was a dried up swamp, and across this I 
rode with the Commissioner at 5.30 one evening. Although we had to walk our 
horses across the swamp owing to the broken nature of the surface, no biting flies 
of any kind were to be seen. It was two days after full moon (March 24th), and 
when I was riding back between 9.30 and 10 p.m. the pony showed signs of 
irritation, became restive and kept swishing his tail about vigorously. As we 
had had a very bad encounter with a swarm of bees a few days previously, and, 
as there was a distinct buzzing sound, I became apprehensive. The buzzing 
increased, and numerous flies made repeated darts at my head, neck, and hands ; 
I managed to secure two of these gorged with blood. The pony, by this time, 
was well-nigh uncontrollable and I made for camp. On examination the two 
flies proved to be Glossina morsitans. There could not have been fewer than 100 
of them, and their persistence of attack, and the buzzing sound emitted, were 
more suggestive of Hymenoptera than tsetse. 
Immediately after leaving Tento, the road runs parallel with the Nianija Bolon 
at a distance of less than 100 yards from it. The whole way to Niani Bantang, 
where the creek is crossed by a “crinking” (interwoven strips of bamboo) 
bridge, the country is fairly open and extensively cultivated, but the banks of the 
ereek are covered with dense bush and high shady trees. There were a few dry 
places, but the greater part of the Bolon still retained water. I halted for a 
time at the Nianga crossing, but on or around the pony (which generally acts as 
a tsetse decoy) only Stomoxys nigra was found, apart from other non-blood- 
sucking Diptera, which are irritating to horses and cattle, and very annoying to 
man. 
From Niani Bantang to Jalo Kunda the road passes through open thin bush, 
The headman of Niani Bantang informed me that both tsetse and large 
Tabanids swarm there during the rains, but in the dry season are extremely rare. 
From Jalo Kunda to Gassan, the road is through thin bush and bamboo, the 
latter predominating where there is a preponderance of laterite and little or no 
telluric moisture. The camp at Gassan is close to a swamp, and a species 
of Anopheline, Nyssorhynchus pharoensis, was caught in one of the houses at 
10 a.m. ; this was the first mosquito seen since leaving Bathurst. 
The town of Gassan being close to the river, I took the opportunity of 
examining a portion of the latter to see to what extent anyone, rowing close to 
the river bank, would be subject to attack by tsetse. For this purpose, I got 
a native canoe, or dug-out, and proceeded to Wassu, a small wharf about three 
miles further up the river, always keeping within 50 yards of the bank. The 
