On the Effects of Depilatory Roentgen Irradiation and of Concomitant Administration of Cortisone on Hair Growth in Mice*†*From the Department of Dermatology and Syphilology of the New York University Post-Graduate Medical School (Dr. Marion B. Sulzberger, Chairman) and the Skin and Cancer Unit of the University Hospital, New York, N. Y.†This investigation was supported by Grant C-3756 A&I from the U. S. Public Health Service.