This series includes correspondence, memoranda, reports and other records of a general administrative nature of the Director of the Preventable Diseases Branch. The records from 1945 through 1963 are particularly the files of Dr. Lester M. Petrie and reflect his work as Director probably as much as they reflect the work of the Preventable Diseases Branch. Dr. Petrie served as Director of the Industrial Hygiene Service from 1941 to 1952 before becoming Director of Preventable Diseases Branch and the records of this series prior to 1952 are in effect the general administrative records of the Industrial Hygiene Service.