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were found infected, one had come from a malarious district and had suffered from a previous attack. The Tai Hang nullah above the road is untrained and there are vegetable gardens and hill streams in the neighbourhood. No infections were found in the mosquitoes captured.
(6) Tung Wah East Ravine. (In the East-end suburbs of Victoria).
Catching was done in the matsheds housing 40 labourers engaged in training one of the Tung Wah East ravine streams which runs between Broadwood Road and Tung Wah Eastern Hospital. One labourer with parasites found in his blood had been working for six days there.
(7) Hong Kong Volunteer Defence Corps Camp.
Members of the staff who were under canvas during four week ends in November and December obtained 25 Anophelines from the medical tent between dusk and 10 p.m., 14 A. hyrcanus, 9 A. jeyporiensis, 1 A. maculatus, 1 A. splendidus (maculipalpis). These were dissected for malarial and filarial infections, but none found.
(d) INVESTIGATIONS AS TO PREVALENCE OF MALARIA IN CERTAIN AREAS.
(1) Shing Mun. Investigation and Prevention.
It will be seen on reference to the map that the Camp is situated 500 feet above sea level on ground which slopes southwards from Tai Mo Shan Ridge to Gin Drinkers Bay. East of the Camp is the Shing Mun river. The Gorge where the Dam is being constructed is half a mile distant. The Shing Mun river rises east of Tai Mo Shan, flows south to Pineapple Pass, and afterwards turns east to Tidal Cove at Shatin.
Flowing south from Tai Mo Shan to Gin Drinkers Bay is a large stream B, with numerous branches which lie on all sides of the Camp. The streams are rocky bedded and boulder strewn, the boulders being of all sizes and shapes; in places the streams are very steeply graded, in others the grade is flat. Sometimes the course leads through deep gorges. In some of the valleys rice fields arranged in terraces have been constructed by building a series of stone walls across them in order to retain the soil thrown down, the stream being usually diverted to one side and used as an irrigation ditch. In some instances the irrigation ditch is entirely fed by seepages, in others, as in the case of fallow rice fields, sometimes no irrigation ditch could be demonstrated, but only seepage water.