1910.] Diseases of Domestic Animals in Uganda. 



477 



the year. As a rule, there are a few Tahanulcc. The cattle belonging to 

 the Commission went down to the foot of the hill every morning to graze, 

 and returned to their kraal on the top at sunset. Half of the herd went to 

 the east of the hill and half to the west. On both sides there was a small 

 valley or glen, through which ran a small stream. In these valleys during 

 the year, as a rule, a Tahanns or two or a Ha-matojMa could be seen, but they 

 were in small numbers. Now it is a curious fact that at certain times of 

 the year enormous numbers of Tahanidcc will suddenly appear in places 

 where only a few are, as a rule, to be found. For example, Mr. Brown, at 

 Mabira, who was collecting the biting flies of his district, wrote on March 14, 

 1909, that the Tabaniclce, which for months had been scarce, were then 

 swarming everywhere in countless numbers, and he afterwards wrote that 

 this invasion lasted about a month. The particular species which appeared 

 at jNIabira at this time was Tabanns socialis (Walk.). 



So, in the same way, at Mpumu, the Tahanidcc, which had been rare, 

 suddenly appeared in swarms. They were first seen in the valley to the 

 west of the hill in September, 1909, and a month later in the valley to the 

 east. Soon after this the cattle which had shown no signs of disease during 

 the previous year were found to be suffering from Trypanosoma pecorum. 

 Those which grazed in the valley to the west were the first to be affected, 

 and afterwards those which grazed to the east of the hill. The species of 

 Tahanidcc in this case was Tahanns secedens (Walk.). In both groups of cattle 

 there were cases of Trypanosoma pecm-uvi disease, so that the Tahanidce had a 

 reservoir from which to draw the virus. 



Another sudden epidemic of Trypanosoina pecorum disease occurred on 

 Mr. Walsh's farm at Kabula Muliro, where, as stated above, 34 milch cattle 

 died within two months in a herd of 300. The evidence is all against this 

 epidemic having been caused by tsetse flies. During February and ^larch, 

 and again later in the year, during August and September, as many as 

 100 fly-boys were engaged scouring this district for biting flies. Tahanidoe, 

 Hcematopota, and Chrysops were brought in, but not a single tsetse, although 

 a reward of 5 rupees was offered for each specimen. The commonest 

 Tahanus in this district during August was varictv.s (Walk.). 



It may, therefore, in our opinion, be concluded that the trypanosome 

 disease caused by Trypanosovia pecorum can be carried from sick to healthy 

 animals without the aid of Glossinoe, but what other species of fly, if any, 

 acts as carrier is merely a matter of speculation at present. 



Stomoxys. — Montgomery and Kinghorn state that they have strong 

 evidence against this genus. At Mpi;mu several experiments were made to 

 attempt to settle this question, but although they were persevered in for 



