Polyploidy and Sex Chromosomes

Abstract

PROF. RUGGLES GATES introduces hybridity with chromosome incompatibility as a possible source of polyploid series in plant genera. In my note I deliberately refrained from referring to this theoretical possibility because neither in intrasectional crosses nor in the widest possible intersectional willow crosses known to me does the remotest approach to total chromosome incompatibility occur. Furthermore, in my opinion, such a state of affairs is not likely to arise, or to have arisen, in Salix hybrids.