Genetic trisomic tests for chromosome 1 have given significant segregations for y, the ratios being 59+:7y in F2 and 72+:29y in BC, the heterozygous parent in each case having had a single dose of y. It is surprising that such a long chromosome did not turn up with a correspondingly long linkage group as in the case of chromosome 2. The relatively long linkage group V must belong to a much shorter chromosome.
A manuscript summarizing all of our trisomic work to date has been submitted for publication.