I. FOREWORD

The notes are again arranged in order by city this year; if this has been helpful in locating and in reading, it is because it is a good idea that was used by the early editors of the News Letter.

50 years ago (Dec. 19, 1929; February 5, 1930; April 17, 1930; July 26, 1930) lists of linkage groups, revised "rainbow" maps, linkage data and references were distributed from Cornell. These are reproduced in this issue from the copy of E. G. Anderson.

About 800 copies of this issue will be sent to research workers, laboratories and libraries around the world. The costs of preparation, reproduction and mailing continue to be borne by National Science Foundation grant funds to the University of Illinois for the Stock Center. The year-round office workload for the News Letter is supported by the U. S. Department of Agriculture, and facilities are provided by the University of Missouri. Their support is indispensable and we all owe a debt of gratitude to them.

Mapping studies are increasing. Several cooperators have suggested that organized mapping needs to be done by the Coop (or perhaps by a specific center, supported by a national agency); some suggest that the News Letter (i.e., your editor) make compilations and coordination; some that a committee be formed; some that cooperation simply be encouraged. Responding to a call for cooperators to identify interest in mapping particular chromosomes, D. S. Robertson indicates active mapping of chlorophyll factors on chromosome 6; R. H. Whalen tenders interest in factors on chromosome 7; and W. R. Carlson in factors on chromosome 9.

In this News Letter, "Zealand 1980" is an attempt to bring together new factors and linkage information in the formal literature and in the notes for the year just past; perhaps this will be a useful device (please give reactions). A brave, new working map for chromosome 3, constructed from the ground up by review of data in Emerson, Beadle and Fraser and the News Letter, is included; new data and clarifications would be most welcome.

An index of genetic and cytogenetic symbols in Corn and Corn Improvement, 2d edition (G. F. Sprague, ed.) is available upon request.

Back issues can be supplied on request.

A microfilm of volumes 1-29 and 33 is available for $9.50 U.S.; checks should be made out to E. H. Coe, Jr.

Airmail service to addresses outside the U.S. will be provided for $3.00 if received by January 1st.

Deadline for the next issue is January 1, 1981; see inside front cover.

I appreciate the encouragement and support of M. G. Neuffer, J. B. Beckett and G. G. Doyle in planning and developing this volume; Ming-Tang Chang, Christine Curtis, Man Mohan Johri, Kathryn Kind, Stephen Modena and Manh Nguyen aided in editing and proofing of copy; Pat Berry and Shirley Kowalewski carried out the office and bibliographic work; Mary Nelson once again applied her thorough, precise and diligent attention to the composition work and to the production of final copy.

E. H. Coe, Jr., Geneticist, USDA-SEA-AR; Professor of Agronomy Curtis Hall, University of Missouri, Columbia, Missouri 65211