FEDERAL SECURITY AGENCY © Public Health Service NATIONAL INSTITUTES OF HEALTH © Bethesda 14, Md. NATIONAL INSTITUTE OF ARTHRITIS AND METABOLIC DISEASES November 13 ’ 1951 NATIONAL CANCER INSTITUTE NATIONAL INSTITUTE OF DENTAL RESEARCH NATIONAL HEART INSTITUTE NATIONAL INSTITUTE OF MENTAL HEALTH NATIONAL MICROBIOLOGICAL INSTITUTE NATIONAL INSTITUTE OF NEUROLOGICAL DISEASES AND BLINDNESS AIR MAIL THE CLINICAL CENTER — DIVISION OF RESEARCH GRANTS Dr. Joshua Lederberg University of Wisconsin College of Agriculture Madison 6, Wisconsin Dear Josh: I enclose a manuscript which has beenagceptai for publication by the "Journal of Bacteriology", on which I would welcome your critical and helpful comments. I hope you do not object to my including the reference to your paper which I saw in manuscript copy a few weeks ago. The enclosure is the only laboratory copy, and I would be grate- ful for its return. Experimental |Therapeutics National Microbjological Institute HEskm Enc.