6x 
all thick underbrush and rank grass, either near the water or a few 
hundred yards inland, be carefully removed.* 
The station of Irebu, a military training post on the middle Congo, is beautifully 
bept. We remained there for three days and saw no tsetses, although there were mam 
only a few hundred yards further up or down the river. A little over 1,000 yards 
outside the station was a trading factory placed in the middle of a patch of rank grass 
Glossina falfalis existed there. Resides searching for tsetses on the station ourselves 
we sent out five boys trained to catch them, together with 60 soldiers. Between them 
all only a dozen specimens were taken. All were caught in a patch of rank grass, 
about 350 yards from the river, that had not been cut for two or three months. There 
were many scores of acres of cultivated land on the station, mostly consisting of well 
kept, but shady, cocoa and coffee plantations. In them not one tsetse was found. 
As Leopoldville developes and the surrounding brush is kept down tsetses become 
fewer, and we are told they are not nearly so numerous within the Protestant mission 
station as they formerly were. During our stay in Leopoldville Glossina palpatis was 
much more often caught in the house of the Rev. Mr. Morgan than in the building 
occupied by our expedition. The mission house was surrounded by a grove of palm 
trees which extended uninterruptedly to the river’s edge, while the house of the 
expedition stood in an open piece of ground. 
The experimental farm of the Government of the Congo Free 
State at Eala possibly may be considered to be an exception to this 
rule. 
This farm is comparatively free from undergrowth. It is extensive and well kept, 
yet Glossina falpalis is quite frequently seen on it. There is a herd of 43 cattle 
and a fair amount of other live stock on the farm. It is believed that the flies are 
attracted by them. 
It often happened, however, that no,, or extremely few, tsetses were 
found, even after a careful search, in places where everything, shade, 
shelter and water, apparently favoured their presence. 
Near Yambinga a search (of several hours), made on a bright day, along the 
thickly wooded banks of the main river of a small stream failed to find Glossina 
fal falls, although they were present in the near neighbourhood. 
At Yakusu several hours in the middle of a fine dry day were spent in a canoe 
paddling along the banks of the river and about wooded islands. Tsetse flies were 
not seen. 
The late Rev. W. Holman Rently told us that at a place called Vela in the Lower 
Longo G. falpalis was absent. The natives noticed this and decided that they were 
-.offering from a want of the beneficent blood-letting enjoyed by their neighbours wh'. 
ived in places where the fly existed. Men were therefore sent out to catch tsetses, 
bring them back and let them loose at Vela ! 
Rehind the soldiers’ lines at T.usambo runs a brush-covered stream which never 
u* 1 ^f iar La ma ' ad ’ e du sommeil et la tse-tse a Novo Redondo. Reports 
o t e 1 teenth International Congress of Medicine at Lisbon, Fasicule 2. 
page 294. It is stated in this publication that Glossina falpalis is not 
>een in well-kept plantations nor at a higher altitude than 400 metres above the sea 
I his latter assertion is negatived by an observation of Commandant Charles Lemaire. 
who sent us specimens of the fly from the banks of the Ialo River (6° 33' North : 
29° 58 Last) caught at an altitude of 530 metres, and also by Lieutenant Rrohez. 
who caught Glossina at an altitude of 1,600 metres, in places where the moraine 
temperature went down to o° C. (loc. cit., vide infra). 
