739
6. In considering the percentage of Anopheles in the foregoing table, two modifying circumstances require to be allowed for. The percentage for October, 1900, is too high, owing to the fact that I was then receiving an unduly large number of insects from the more malarial Police Stations, and less in proportion from the more healthy stations. And on the other hand, the percentage of Anopheles shown for August and September, 1901, is probably much below the average for the Colony as a whole during those months, owing to the fact that from the end of June vigorous measures for the destruction of the larva and breeding-places of these insects were in operation in the neghibourhood of all my collecting stations. I drew up a series of simple instrutions on this subject, as brief and elementary as possible, and these were embodied in a General Order to officers in charge of Police Stations by the Captain Superintendent of Police (v. Appendix III). They were carried into effect more or less thoroughly, and, while the Police reaped the benefit, my statistics were vitiated in the direction I have indicated. Allowing for these modifying circumstances, it will be found that the prevalence of the Anopheles mosquito runs quite parallel with what we already know of the prevalence of malaria in the Colony. Both are at their minimum in February, and at their maximum between the months of July and October.
7. No Anopheles were found among mosquitoes sent to me from the following stations:-
No. 5, No. 6, No. 7, No. 8, Kennedy Town, Mount Gough, Shaukiwan, Tsim Sha Tsui,
Stone Cutters' Island, Hung Hom, and Kat 0.
8. The following Table shows the stations from which Anopheles were sent to me, and the per- centage of Anopheles among the total mosquitoes received from those stations:-
Anopheles.
Culex.
Mosquitoes examined.
Number.
Per cent.
Number.
Per cent.
No. 1 Station,
1,261
6
0.5
1,255
99.5
No. 2 Station,
575
1
0.2
574
99.8
No. 3 Station,
1,178
1
0.1
1,177
99.9
Pokfulam,
852
21
2.5
831
97.5
Aberdeen,
688
7
1.
681
99.
Stanley,
963
15
1.6
948
98.4
Shek O,
748
116
15.5
632
84.5
Tsat Tsze Mui,
600
47
7.8
553
92.2
Yaumati,
1,066
1
0.1
1,065
99.9
Fuk Tsun Heung,
558
1
0.2
557
99.8
Kowloon City,
1,717
1
0.1
1,716
99.9
Sha Tin,
572
43
7.5
529
92.5
Sai Kung,
552
8
1.4
544
98.6
Tai Po,
809
191
23.6
618
76.4
Sha Tau Kok,
4,401
414
9.4
3,987
90.6
Sheung Shui,
815
10
1.2
805
98.8
San Tin,
837
14
1.7
823
98.3
Au Tau,
1,841
113
6.1
1,728
93.9
Ping Shan,
245
12
4.9
233
95.1
Tai O,
399
38
9.5
361
90.5
Tung Chung,
226
78
34.5
148
65.5
Ch'eung Chau,
4,704
1
00.2
4,703
99.98
Lamma,
604
30
5.
574
95.
•
9. In Appendix II I describe systematically the mosquitoes that prevail in the Colony, examin- ing in each case the wings, legs, head, appendages, thorax, abdomen, and size. The size I express in millimetres (inch). It will be noted that, so far as Hongkong is concerned, the wings of Anopheles are in all species spotted, and those of all forms of Culex unspotted.
There are three species of Anopheles-a sub-species of Anopheles Sinensis, and two species which have been recognised as new species, not thus far observed elsewhere, by Mr. F. V. THEOBALD, Ento- mologist at the British Museum, to whom I submitted them. He has named one of them Anopheles Maculatus from its markings, the other Anopheles Minimus from its minute size. The former I at first belived to correspond to Anopheles Costalis of West and South Africa, but there are specific differences. I need not here enter into descriptive details, which I have set forth at length in the Appendix.
Anopheles Sinensis breeds chiefly in the rice-fields and the ditches surrounding or draining them, the other two chiefly in the ravines; but they do not confine themselves exclusively to their usual habitats.