Peter T. Beardsley, R. Edwin Brady, Bryce Rea, Jr., Guy H. Postell, John W. McFadden, Harry C. Ames, Roland Rice, Homer S. Carpenter, John S. Fessenden and Richard R. Sigmon, for appellants.

Solicitor General Marshall, Assistant Attorney General Turner, Howard E. Shapiro, Robert W. Ginnane and Leonard S. Goodman, for the United States and others.

William Q. Keenan, for intervenor Railway Express Agency, Inc.

Arthur A. Arsham, for intervenors National Small Shipments Traffic Conference, Inc., and others.

PER CURIAM.