Charles A. Coolidge '17, Senior Fellow of Harvard College will retire effective July 1. William L. Marbury, who has been a Fellow since 1947, will succeed him as Senior Fellow, and the vacancy on the Corporation will be filled by Albert L. Nickerson '33, chairman of the board of the Socony Mobil Oil Corp.

Nickerson will have completed a six-year term as Overseer when he joins the Corporation. He has been chairman of the Overseers' Committee to Visit Harvard College, as well as a member of the Overseers' Executive Committee on University Resources.

The Corporation consists of the five Fellows of the College, the President and the Treasurer. It acts as a body in determining the policies and day-to-day business of the University, though its major decisions require the consent of the 30-man Board of Overseers.

Coolidge, the retiring Senior Fellow, will be 70 next fall. At Harvard he was Second Class Marshal, president of the Student Council, president of Phillips Brooks House Association and a member of the football team. After infantry service in World War I, he attended Harvard Law School and was graduated in 1922.

A partner in the Boston law firm of Ropes & Gray, he has filled major posts in the State and Defense Departments under both Republican and Democratic administrations.

For eight months in 1953, after President James B. Conant left to become U.S. High Commissioner to Germany and before President Pusey assumed office, Mr. Coolidge served on a four-man committee which exercised the functions of President. He was also designated Acting President during Pusey's extended visit to the Orient in 1961.

Marbury, who succeeds Coolidge as Senior Fellow, lives in Baltimore, where he serves as chairman of the board of the Peabody Institute of Baltimore and Chancellor of the Episcopal Diocese of Maryland. He was chairman of the Commission on Higher Education in 1946-47, and general counsel for the Maryland Port Authority.

Now 63, Marbury was graduated from the University of Virginia in 1921 and from Harvard Law School in 1924. Since 1931, he has been a member of the Baltimore law firm of Piper & Marbury. He received the U.S. Medal of Merit in 1945, for wartime service in the War Department.