Abstract
The hybrids derived from the crossing, Tulipa Gesneriana L. X T. Fosteriana Hoog., are called Darwin Tulip-hybrids. In Holland, they succeeded to make popular and promising varieties from this crossing, and some of them were imported to Japan recently. Being combined several features of T. Fosteriana, such as a big flower with glossy scarlet color, earliness of flowering time and resistance to disease, with that of Darwin Tulips, these varieties are very excellent. Although parental varieties used to make these hybrid varieties are not known entirely in our country, some workers have begun to hybridize Darwin Tulips with T. Fosterialea so as to make new varieties. As an exact knowledge with reference to the chromosornal constitutions of the existing Darwin Tulip-hybrid varieties is rea-sonably considered to be suggestive to give satisfa-ctory results in such breeding programs, the au-thors has begun to make cytological studies on them.
