10

The following chart shows the prevalence of the biting-
flies under consideration in the surra season ("rains") in the
valley generally:—

[NLS note: a graphic appears here - see image of page]

The rains were exceptionally heavy this year and lasted
from 28th June to the middle of September. In 1907, the
previous year, there had been a failure of the rains. In
1908, the villagers said that the number of Tabanus was
less than usual.

The daily variations in numbers of flies were too great
to be shown on the chart.

Tabanus and Stomoxys increased suddenly on the 3rd
day of the rains; mosquitoes appeared on the 4th or 5th day
of the rains, sand-flies about the 8th day, Hæmatopota
increased slowly in numbers and were not numerous until
about three weeks after the break of the rains.

Our ponies were all kept in the stable from 28th June
to 19th July ; it was then found that few biting-flies ventured
into it, so on and after 19th July we tied up the surra pony
and controls immediately outside the stable when the
weather permitted, but still in close contact with the two