2. Assignment of linkage groups. One of the topics discussed at a special meeting of maize geneticists at the A A A S meetings in Indianapolis, was the problem of linking workable genes and developing more desirable tester stocks. This is an important question because there are more than 50 suitable genes that haven't been linked and some of the chromosomes are poorly marked.

The plan previously outlined for linking new genes has not been fundamentally changed, but it may well be reviewed here. Each of the ten linkage groups in maize has been assigned to one, or more, cooperator who is charged with testing unplaced characters with his particular chromosome and building up suitable tester stocks. The following assignments have been made:

• Chromosome 1.   Emerson.
• Chromosome 2.   Rhoades and Clokey.
• Chromosome 3.   Brink and Woodworth,
• Chromosome 4.   Singleton and Brunson.
• Chromosome 5.   Burnham.
• Chromosome 6.   Stadler and Lebedeff.
• Chromosome 7.   Jenkins and Fraser.
• Chromosome 8.   Sprague and Perry.
• Chromosome 9.   Eyster and Shafer.
• Chromosome 10.  Lindstrom, Wentz, and Bryan.

When a new gene is found, a few seeds involving it should be sent to the secretary of the Maize Genetics Cooperation who will grow them in an increase block and obtain a liberal supply of seed for the central repository. Then the secretary will send a few seeds to each of the above geneticists who will test for linkage in his particular chromosome.

This system has been devised not to limit the number of workers who are trying to link new genes, but rather to insure the linkage of every workable gene.