16
Shifting of laboratory to new tempo -
rary building.
There, was a further dislocation of work, as the laboratory had to be
moved to allow of an extension of the science class
rooms of the Government College.
Malaria surveys completed.
Malaria surveys of Thanesar, Montgomery, Mianwali, Gujranwala, and
Lyallpur taken up last year, were completed.
Short notes on these will be submitted as soon
as practicable. A detailed report on the survey of Thanesar is about to be
submitted.
Surveys undertaken.
Surveys of the towns of Gohana and Khangarh were undertaken, as
malaria is markedly endemic in both of them.
Why Gohana Was chosen.
That of Gohana may, it is thought, yield some interesting results owing
to a remodelling of the "Western Jumna Canal
system by which there has been a much lessened
supply of water for irrigation.
Why Khangarh was chosen.
The town of Khangarh has shown a very high rate of infantile
mortality, with a high total mortality for
which fever was mainly responsible.
Dissection of anopheles.
Some thousands of anopheles were dissected to determine the species
of the local carriers in places under survey
and of other visited during the year.
Dissection of A. Rossi.
Innumerable A. Rossi were again dissected, to decide, if possible
whether they are ever carriers in nature, and if the
parasites could undergo in them changes at any
stage of their development ; but with a negative result. It seems, however, that
some definite results may be obtained, as in Khewra, with very limited breeding
places, the spleen-rate has been found to be as high as 64.46 and the only
species found there hitherto is A. Rossi. It has been remarked by certain
observers that A. Rossi becomes infected if the larvae breed in brackish water
and Khewra may well furnish confirmation of this observation.
'
Visits paid to :—
Khewra.
The towns of Khewra, Katas, Choa Saidan Shah, and Kallar Kahar in
the Jhelum District were visited. At Khewa an
attempt was made to decide if anopheline larvae
could breed in the brackish water of a stream
running at the foot of the salt range, or in
the waters of small lakes found within the salt mines. No larvae but
two imagines of A. Eossi were found after an exhaustive search The
presence of as high a spleen-rate as 64.46 and a parasite-rate of 14.87 in the
face of the absence of anopheles fauna is puzzling ; it is hoped to throw
more light on this problem m the present year.
Katas.
The town of Katas was visited to ascertain whether anopheles larvae
were breeding in the sacred tank, in which there
are innumerable fish. Larvae were found to
abound side by side with the fish m the weeds and in the middle of the tank
Specimens of the fish, which, permitted to be caught after exercising a con-
siderable amount of tact, were identified as Cirhina Latia (Ham Buch) 8
Fish caught from sacred tank in Katas.
specimens and Barbus Terio (Ham Buch) 97
specimens, both of which, specially when young,
are destroyers of insect larvae. From this it would appear as if fish did very
little injury to anopheles larvae. A similar result was met with in the tanks
at the Shalamar Gardens at Lahore, into which fish of larvicidal species were
specially introduced to reduce the number of anopheles larvae.