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disease to man. Indeed all the evidence at present is against the spread of plague by insects by inoculation, and that the mode of conveyance of protozoal diseases, e.g., malaria, is quite different from those due to micro-organisms of the well recognised types.

In regard to the question of the communication of the disense, direct from person to person, I have already pointed out in my Report ou Plague, that instances of such cases- apart from pneomonic plague-must be rare indeed. In his recent Report on Plague, ASHBURTON THOMPSON deals with this point, more or less thoroughly, and the conclusions which he has formulated are practically the same as those of my own. Therefore, it would appear that plague is not "so catching" as previously insisted upon, and that during the course of different epidemics, the diffusion of the disease was not direct--from person to person-but "incidental to conditions which obtained independeutly of man." (Thompson),

The use of the Virus of DANYSZ to exterminate rats is to be regarded as signal failure in Hongkong. Our local results are in agreement with these obtained in Sydney, South Africa, and elsewhere. The majority of reliable reports pronounce this virus to be of no use.

Bacteriological Investigations.

During the past year a considerable amount of pure bacteriological work has been done. So far, no attempt has been made to prepare the more complicated vaccines and sera, e.g., the plague prophylactic, and various plague sera. It was felt that until the completion of the Bacteriological Institute, the preparation of such would be attended by considerable risk.

The amount of clinical bacteriology done during the year is greatly in excess of previous years. This applies, not only to the number of examinations carried out for various Government Medical and Sanitary Institutions of the Colony, but, also, I am glad to say, to those which have been forwarded to me by medical men in Hongkong, and neighbouring ports. It is to be hoped that, with the establishment of the Bacteriological Institute in Hongkong, as a thoroughly equipped and working institution, considerable progress will be made in regard to our knowledge of the diseases existent amongst the Chinese. Indeed, I feel convinced, that, given the co-operation of our medical and sanitary authorities in Hongkong much can be accomplished along many different lines of investigation.

1. Relapsing Fever.-One case of this disease was examined pathologically and bacte- riologically. It was not naturally acquired in the Colony but imported from a Northern port of China. This disease does not, at present, exist in the Colony. Nothing characteristic could be made out of the autopsy, but microscopically numerous examples of the specific spirochacte were found. Attempts were made by Dr. Koci and myself to cultivate these organisms outside the body. So far the results obtained have been unsatisfactory. This spirillum would appear to be allied to the genus Trypanosoma, Its exact phase has so far been undetermined. There is every reason to believe that this discase is spread by a special species of Culex Mosquito, examples of which are, in all probability, well represented in the Colony. Should further cases of the disease come before my notice, I propose to carry out investigations as to the exact position of the spirillum in protozoology and its probable insectivorous spread from man tɔ man.

2. Malta Fever.-Throughout the past year, an outlook has been kept for cases of this disease. The malady has a wide geegraphical distribution and cases have been reported from Hongkong. The majority of the latter belong to the Naval Authorities who have imported cases from countries Turther West. Cases of continued and intermittent fever have been repeatedly tested for the specific serum reaction but with negative results. So far as my own personal experience is concerned, I have no knowledge of any case of Malta Fever originating in the Colony.

3. Typhoid Fever.-Over 50 cases of suspected Typhoid Fever have been examined by Widal's test during the past year. In the majority of instances, the test has been performed with blood serum obtained from in-patients of the Government Civil Hospital. In the majority of cases, a satisfactory result has been obtained. The test, like all others, is not infallible, yet remains as a valuable adjunct to the diagnosis of doubtful cases of the disease.

4. Diphtheria.-A few cases of the disease were found during the year. The usual tests were made, namely, cultivation of a swab smear on blood serum with subsequent microscopic examination of the growth after applying various tests, e.g., Gram's method, Neisser's stain, etc. This disease would not appear to be common in Hongkong. On the