Slightly more than 200 cultures were grown last summer. About half of these were the F1 hybrids between weak stocks and non-related inbreds made by Dr. Murray in 1943. A few plants were selfed in each of these cultures. This program was carried along by growing still other weak stocks and crossing them with inbreds. It is hoped that in the course of a few years most of the useful genes can be put into vigorous combinations of this kind. In cooperation with Dr. Randolph, a beginning was made of the transfer of a good marker gene or two to each of the trisomic stocks now available. Combinations involving trisomic V, VI, IX, and X were obtained this year.

R. L. Cushing and Rosalind Morris