From the Research Laboratory, Department of Pathology, Free Hospital for Women, Brookline, Mass., and the Departments of Pathology, Obstetrics and Gynecology, Harvard Medical School, Boston, Mass.

^*Rockefeller Research Fellow. Present address: Queen Charlotte Hospital, London, England.

The investigation reported in this paper was supported by Research Grants C-2378, C-1471 and C-2451 (c) from the National Cancer Institute of the National Institutes of Health, U. S. Public Health Service.

Submitted for publication Nov. 7, 1960.