Races of A. Stephensi Liston, 1901 *The work here reported was done with the support and under the auspices of the Department of Health, Government of Mysore, and the International Health Division of the Rockefeller Foundation.

possibilities. During a study of village malaria in Mysore State (Sweet, 1937), several anophelines were studied, including A. stephensi, from various parts of the State, but no evidence of races of Indian anophelines based on egg patterns could be found and it was concluded that other methods to distinguish possible differences would have to be used. Such a new approach to the subject was suggested by Walch and Walch-Sorgdrager (1935 and 1936), who found considerable differences in the measurements of ova of the Indian and Malaj^an forms of A. subpictus. [We are indebted to Strickland and Roy (1936) for the reference.] Several references have been made at various times to the possibility of the existence of two races of A. stephensi, amongst which may be mentioned Knowles and Basu (1934), Ramsay and Macdonald (1936), and Mulligan and Baily (1936). Our own experience in Mysore seemed to indicate two races and for over a year we have been making measurements of ova of this species obtained from various parts of India. Since the results of these measurements seem to point to the existence of two races of A. stephensi, this preliminary report seems justified, although much more work remains to be done before definite conclusions can be drawn.