From the Department of Obstetrics and Gynecology and Division of Research, The Lankenau Hospital, Philadelphia, Pa.

This work was supported by Grant E-209 of the American Cancer Society.

The cooperation and advice of Clark E. Brown, M.D., Department of Pathology and George C. Lewis, M.D., Department of Obstetrics and Gynecology are gratefully acknowledged.

Submitted for publication May 10, 1961.