1939 Volume 53 Issue 636 Pages 549-556
1. A number of male and female tetraploids have been induced in Melandrium album by colchicine method.
2. Conjugations of sex chromosomes at the meiotic divisions in the induced tetraploid males are illustrated in figs. 5 a-f and table 3.
3. The induced tetraploids and normal diploids were intercrossed and a considerable number of seedlings were obtained (table 4). Some of them have been examined cytologically and determined to be triploid (figs. 8-9), tetraploid (fig. 10) or heteroploid (fig. 11).
4. In comparing size relations between the X and the Y chromosomes in somatic cells, it was ascertained that the Y is the larger member of the sex chromosomes.