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A. minimus, A. jeyporiensis, and A. maculatus. Pigment hitherto encountered in the oocysts has been considered to be that of the benign tertian parasite, but the oocysts found in one midgut contained somewhat coarse dark pigment. From precipitin tests it appears to be zoophyllic for choice.
9. It is noteworthy that the catches of adult mosquitos at several stations were found to be far less numerous than those of preceding years owing to preventive work done.
10. Anti-malarial measures were carried out in many areas on the Island and mainland during 1937, and particular attention was given to the following amongst other places:
(a) Shek O, (b) Tytam Tuk, (c) Stanley Gaol, (d) Repulse Bay, (e) Shouson Hill, (f) Aberdeen, (g) Mount Kellett, (h) Pokfulam (including Queen Mary Hospital), (i) Government Quarry North Point, (j) Kai Tak Aerodrome, (k) Kowloon Tong and surroundings, (l) Shing Mun Camp, and (m) Pat Heung Aerodrome.
11. The actual methods employed were rough training of streams, ditching, stone drainage, and oiling. In a portion of one stream which was heavily strewn with boulders which it would have been difficult to move, stones of various sizes were packed between the boulders thus shutting out light from the water.
12. Valuable work was also undertaken by the Bureau where mosquito nuisance was specially aggravated. C. fatigans, A. (S) albopictus, and A. (F) togoi were the species most frequently incriminated.
13. Four tables are appended. The first table gives details of nearly 12,000 anopheline larvae examined microscopically for identification purposes; the second relates to some 1,878 adults hatched out from larvae and pupae; the third summarises certain of the results of precipitin tests on bloods from mosquitos caught in various localities and in different shelters; while the fourth table gives a summary of systematic catches and dissections to ascertain the presence of malarial infection of anophelines caught at Pat Heung Camp in two "screened" lines. The numbers of A. minimus greatly exceeded those of A. jeyporiensis even though rice fields abounded along the hill-foots. In addition, catching was also done in villages outside the half mile area around these lines. Of 1,550 anophelines obtained approximately 60% were A. hyrcanus, 20% A. minimus, 12% A. jeyporiensis, 7% A. tessellatus (a high rate for this species), and 1% A. maculatus.
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