MOSQUITOS OF SOME PORTS OF CHINA AND JAPAN. 403 



but have since served as dumping grounds for all sorts of organic refuse, chiefly of 

 vegetable origin. They were also found sparingly in several places in ill-smelling 

 water in pans placed under flower-pots. The species was certainly the dominant 

 one in the town. 



Culex tritaeniorhynchus. — The larvae of this species were found sparingly in the 

 rice-fields associated with those of A . liyrcaniis. 



Anopheles hvrcanus. — The larvae of this insect were found in fair abundance on 

 the outskirts of the town in the rice-fields, then at an early stage of cultivation, 

 the planting out of the young plants from the nursery beds having only just com- 

 menced. It was noteworthy that in these beds, longer undisturbed than the open 

 fields, the larvae were far more numerous than in the newly planted fields, possibly 

 b\' reason of the presence of a larger amount of green filamentous algae, on the tufts 

 of which they were invariably found. The larvae were either green in colour, 

 or green with white splashes ; or banding was present to a varying degree on the 

 thorax, 3rd, 5th and 8th segments. They did not present that considerable diversity 

 both ojf colour and pattern seen in those of the Malay States. Though they reste'd 

 on a green background, it was eas>' to see them when the sun's rays were 

 oblique, but difficult to do so with the .sun overhead. 



Shanghai. 



Shanghai, the great emporium of Central China and its most important free port, 

 is situatedin latitude3r 14'Northand longitude 121° 29 'East on the left or west bank 

 of the Huangpu River, about twelve miles above its junction with the Yangtze and 

 at a distance of sixty miles from the North Saddle light at the river mouth. 



Three distinct areas, each having its own municipal council, comprise the port, 

 namely, the International Settlement, the French Settlement and the Chinese City. 

 The area within the municipal limits is 8§ square miles, and the quinquennial census 

 of the foreign and Chinese populations residing within the limits and of foreigners 

 living on the outside roads, which was taken on 10th October 1920, showed a total 

 of 26,869 foreigners and 1,661,098 Chinese. Among the foreign population the 

 Japanese were dominant, numbering 10,213 ; the British coming next and numbering 

 5,341. The figures do not include a vast Chinese population residing outside the 

 Settlements. 



The country round Shanghai, which, is devoid of trees, is perfectly flat, stretching 

 as a rich alluvial plain to the west over 45,000 square miles. The area round the town 

 is little above sea-level, so that it does not present a great variety of possible breeding 

 places for mosquitos. 



Trade. — Shanghai is not only a port of trade, but is a large manufacturing and 

 industrial centre to which ships come from all quarters of the globe. 



Temperature and Rainfall. — The annual mean temperature is about 50-9° F. 

 In July and August it runs up to a mean of about 81°, and in January and February 

 drops to a mean of 36° and 37°. In winter, snow and ice are occasionally seen, 

 biting winds sweeping down from the north. A certain amount of rain falls through- 

 out the 5^ear, the annual fall being about 39-97 inches, with a maximum fall of about 

 five inches in June, July, December and February. 



Water Supply. — The pubhc supply for the International Settlement is drawn 

 from the Huangpu, below the town ; that for the French Settlement is obtained some 

 distance above it. It is piped to most of the houses, or is obtainable from standpipes, 

 so that there are practically no wells. 



Sanitation and Quarantine. — The Health Department of the International Settle- 

 ment, under British supervision, is a large one, consisting of a Director with three 

 Assistant Health Officers, fourteen Sanitary Inspectors, and three Sanitary Overseers, 



