RESEARCH IN BRITISH WEST AFRICA. 317 
grass and low shrubs. After Warra, a few rocks begin to appear in the river, but 
navigation is comparatively easy until Bussa is reached. Two days were spent 
on this part, and although the river bank was carefully examined, no biting flies 
of any sort were seen, with the exception of a species of Simulium at Otono, 
where a halt was made for the night. The day was dull, however, and this may 
to some extent account for the absence of insect life. At Bussa, the vegetation 
on the bank is very dense, and there is also abundant grass. In and around a 
banana plantation, close to the river, Glossina palpalis was caught, while nearer 
the Resident’s house, which is situated some distance from the river, G. tach?- 
noides was extremely abundant. Other blood-sucking flies obtained here were : 
Stomoxys nigra, Banksinella luteolateralis and a large new species of Tubanus, 
as yet undescribed. The Resident at Bussa, Mr. P. de Putron, informed me 
that it is almost impossible to keep horses in this district, as they invariably die 
a few months after their arrival. 
Southwards from Bussa, there are numerous rapids, and navigation is both 
difficult and dangerous. Immediately after passing the town of Malali, the 
channel is obstructed by projecting rocks and there is a stretch of cascades and 
whirlpools, which extend for about three miles to the town of Garafini; there 
G. tachinoides was caught. ; 
After Garafini, there is a stretch of about 20 miles of smooth water ; the 
banks are covered with low shrubs, backed by higher trees. No biting flies were 
seen in this part, but the fact that the morning was dull and that some rain fell 
about mid-day, may account for their absence. When passing the mouth of the 
Kontagora River* we caught one G. tachinoides, and another specimen of 
the same species, near the mouth of the River Oli. In this region are the rapids 
of Patassi, which are “composed of two sets of cascades each twelve to fifteen 
feet in height and separated by a straight reach of some two hundred and eighty 
yards.” Following this is a stretch of two and a half miles of comparatively 
smooth water, after which are the Great Rapids of Wuru. “Here the river is 
formed of two branches with a rocky island between. The fall of forty feet 
between the summit and the foot of the rapid is distributed over some 1300 yards 
of river, giving a slope of at least 1 in 100, and a current of from fifteen to 
eighteen miles an hour, In the rains, the granite boulders are completely sub- 
merged under a seething flood, and even in the dry season the water is thrown 
up by the projecting rocks in sheets of foam, and the roar of the rapid is heard 
for long distances on either side.”t Near these rapids G. tach/noides is 
abundant. 
From Leaba to Bajibo, there are numerous rocks in the river, but though navi- 
gation is difficult, it is not very dangerous in the rains. No biting flies were seen 
on this stretch, but the day was again dull. Bajibo is the extreme limit to which 
small stern-wheelers can ascend the Niger even in the wet season, and then only 
with great risks. Between this town and Jebba, G. tachinotdes simply swarms, 
and as many as 25 or 30 invaded the canoe at one time. The banks of the river 
*It may be useful to note here that a specimen of G. palpalis was caught by Mr. P. de 
Putron, the Resident at Bussa, at Kulfu on a branch of the Kontagora River on 26. VI. 10. 
|“ The Geography and Geology of Northern Nigeria.” 
