III. SEED STOCKS PROPAGATED

A complete inventory of material on hand was presented in News Letter 14 and additional lists were given in News Letter 16. Inasmuch as there appear to have been relatively few stocks added to the Coöp collection since 1941, it has seemed unnecessary to present additional lists. Most of the propagation of material during the past few years has merely involved the growing of cultures from old seed, so that genes would not be lost. However, Dr. Murray began in 1943 to outcross weak genetic stocks to inbreds, in order to make material available in more vigorous combinations. This has been continued and a number of such combinations are ready for use. Progress has also been made in the transfer of marker genes to trisomic stocks.

R. L. Cushing and Rosalind Morris