Sessional_Paper_1907 — Page 873

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3. Filariasis.-The disease is rarely met with amongst the Chinese in Hongkong. Two cadavers, with varicose groin lymphatics, were examined during the past year. There was no bistory available as to previous places of residence. In each case, a few Filaria bancrofti were found in the blood.

The Filaria medinensis has not been found during the year.

4. Trichocephalus. In a fair proportion of cases the trichocephalus dispar was found. In no case could it be brought into causal relationship with disease.

5. Trichini Spiralis.-There has never been any evidence of the presence of this parasite in Chinese cadavers.

6. Ankylostoma.--These worms are found rarely, and always in small numbers. This is in spite of the fact that many coolies are brought for post-mortem examination. In one case, reported as death from ankylostomiasis, the body was brought from a ship.

7. Ascaris.-The ascaris lumbricoides is a common inhabitant of the intestines of the Chinese. About 90% of the bodies examined at the Public Mortuary show the presence of this parasite in numbers not often exceeding 20. In one case-a young child-the cause of death was attributed to the presence of these worms in large numbers.

8. Oxyuris.-These parasites would not appear to be common amongst the Chinese in Hongkong.

The Varieties of Rats and Rat-Fleas found in Hongkong.

The preliminary conclusions of the Indian Plague Commission tend to show that the medium of transference of Plague from rats to man is through the agency of fleas. As soon as the published work of the Commission had arrived in the Colony the Honourable the Principal Civil Medical Officer requested Dr. HEANLEY and the Colonial Veterinary Surgeon to investigate the varieties of rats and rat-fleas found in the Colony.

The main conclusions were that the rats, examined between the 15th October and the 15th December, could be roughly divided as follows :—

1. Black Rats-Mus rattus,

2. Brown Rats-Mus decumanus,

3. Mice, Mus musculus,.

4. Musk Rats-Sorex giganteus,

12 per cent.

18

19

48

35

2

5. Undetermined Rats-Size of Mus rattus,

5

3

6. Baby Rats--undetermined,

15

.22

The difference between the black and the brown rat was generally very distinct, only in a small percentage was there any difficulty in determining the species. Difficulty in classifying many rats has also been experienced by observers in India and Japan. This question is one of some importance as there is a general opinion that plague and its trans- ference to man is more generally associated with the black rat.

The fleas found on these rats were:—

Ctenopsylla musculi.

Pulex cheopis. Ceratophyllus fasciatus.

Pulex serraticeps.

The Ctenopsylla musculi was commonly found on black and brown rats, and on mice.

The Pulex cheopis was found in large numbers on the black and brown rat and on the musk rats. The Ceratophyllus fasciatus and Pulex serraticeps were only found once; the former is said to be common in many parts of the world. The latter is the dog flea.