276 DR. T, F. G. MAYER—NOTES ON BLOOD-SUCKING FLIES. 
Glossina palpalis is common all over the district in the rainy season. I have 
caught it when travelling along the following roads in July, 1910, viz :—the 
Oshogbo—ITesha Road, and the Ikerun—Ila—Ipoti road. 
Capt. Humphrey (then District Commissioner, Ilesha) caught this fly along the 
following roads in July, 1910: Uesha—Efon—Ilawe—Igbara-odo—Ikere— 
Ado—Ipoti—Karo—Oke Mesi—lIlesha; and along the following roads in 
September, 1910: Desha—Efon—Apa—Akutan—Igbaraodo—lawe—Ado— 
Ikere—Ise, and on the Ado—Ara road, 
Specimens of the fly were also sent me from Ife by Mr, Wheelwright, Foreman 
of Works. They were caught in September, 1910, 
Sleeping Sickness. 
Whether or not sleeping sickness occurs in these districts it is hard to say. 
My own opinion is that the disease does not exist. The Rev. J. Mackay, a 
missionary of the Church Missionary Society, who has been some seventeen years 
in these districts, says he remembers two cases that may have been sleeping 
sickness occurring five or six yearsago. Not being a medical man he did not like 
to make any more definite statement. He has neither seen nor heard of any 
cases since. If the disease occurs there is no doubt that it is nothing like as 
prevalent as it is on the Gold Coast. 
In this connection it may be mentioned that in these two districts the popula- 
tion is herded into large towns, into which only isolated specimens of Glossina 
palpalis stray with travellers and cattle. There are no small scattered villages. 
Horse Sichness. 
There is no doubt that within the last six years there has been an enormous 
increase of horse sickness. The Chiefs of [a and Ife have complained to me that 
whereas in former days they could ride about in style, they now have to walk or 
hammock from place to place, because they can no longer keep horses for more 
than a few weeks. 
The cause of this is no doubt the pacification of the country, and the subsequent 
introduction of infected horses from Northern Nigeria. It may be mentioned 
that the use of guns by the natives has led to the extermination of practically all 
the game in the district. 
A Plant that kills Mosquito Larvae. 
In attempting to breed out mosquitos from larve, I have two or three times 
been unsuccessful from a curious cause. A green gas-producing plant has 
erown in the water, attaching itself not only to the sides of the vessel, but also 
to the mouth-parts of the larve. A bubble of gas (whether it be oxygen or not, 
I do not know) forms and pulls the larva to the surface of the water, but into 
such a position that it cannot use its syphon tube. In this ridiculous position it 
dies miserably after making the most violent efforts to free itself from this 
inexorable bubble of air. 
