The different forms of flowers on plants of the same species /

Linum grand iflorum, long-styled form utterly sterile with own-form pollen -Linnm perenne, torsion of the pistils in the long-styled form alone-Homostyled species of Linum-Pnlmonaria officinalis, singular difference in self-fertility between the English and German long-styled plants-Pnlmonaria angustifolia shown to he a distinct species, long-styled form completely self-sterile -Polygonum fagopyrum-Various other heterostyled genera -Kubiacese-Mitchella repens, fertility of the flowers in pairs -Houstonia-Faramea, remarkable difference in the pollen-grains of the two forms; torsion of the stamens in the short-styled form alone ; development not as yet perfect-The heterostyled structure in the several Rubiaceous genera not due to descent in common Page 81-136 CHAPTER IV. Heterostyled Teimoephic Plants.