M 99
# H. ANTI PLAGUE WORK
80,757 rats were examined post mortem for signs of plague during the year and 624 spleen smears stained and examined. No positives were recorded in either instance.
The flea survey was continued as in the previous year, 1465 fleas being identified. The results are as follows:
No. of rats X. Cheopis X. astia Types of Fleas found X. braziliensis Ctenocephalus Ceratophyllus Leptopsylla 251 1332 10 5 1 127Cheopis percentage of total fleas 90.92%
General flea index = 5.83
Cheopis index = 5.30
It will be seen that the cheopis index is high. The exact significance of this in the case of Hong Kong cannot yet be stated owing to the many factors involved and it is hoped to subject the figures obtained during the past two years to an exhaustive analysis in order to arrive at their meaning as related to plague expectancy. The complete absence of X. astia and X. braziliensis over a two years period of survey is also noteworthy. The writer has painstakingly sought them, fully expecting to be rewarded by specimens of the species sooner or later, but so far without success. A similar experience has been recorded by Hicks of Shanghai (Jr. of Hygiene, Vol. XXVI, 1927).
# I. MORBID HISTOLOGY
The number of specimens dealt with this year was slightly less than last year. As few specimens as possible were taken from post mortem cases at Victoria Mortuary by the Asst. Bacteriologist on account of pressure of other diagnostic work. It is hoped to resume this work as usual next year. Two hundred and seventeen tissue sections were prepared and examined; of these 11 were malignant growths, 6 occurring in Europeans and 5 in Chinese. Sixty-eight sections were from cases of non-malignant tumours or inflammatory or other pathologic tissues removed at operation. The remaining 138 sections were from post mortem cases, examined for diagnosis or for general pathologic interest.