Results of tests on fiber and manufacturing properties of the principal varieties of cotton produced commercially by cotton improvement groups for the 1955 crop are summarized in this report. Test data are included that were published in monthly reports from August 1955 through January 1956. The cottons for which test results are reported are grouped according to processing procedures employed in making the spinning tests. This facilitates comparisons of the performance in processing of the principal varieties of cotton as produced in the various areas throughout the Cotton Belt.