Includes Record of proceedings, Conference of Collaborators and Population Genetics (NCR 21) Technical Committee Meeting, Iowa State University, Ames, Iowa.

This list includes all serials, printed and processed, received by the Library of the United States Department of Agriculture, on a current basis, as of July 1, 1957. Only dailies or administrative use are omitted. A serial is defined as a publication that is issued either regularly or irregularly over an unspecified period of time. For the purposes of this list, a serial was considered current if it had been received in the Library at any time since January 1954, unless it was known to have ceased.