DETAILED TABLE OF CONTENTS
I. HETEROSTYLED DIMORPHIC PLANTS: PRIMULACEÆ.
Primula veris or the cowslip.—Differences in structure between the two forms.— Their degrees of fertility when legitimately and illegitimately united.—P. elatior, vulgaris, Sinensis, auricula, etc.—Summary on the fertility of the heterostyled species of Primula.—Homostyled species of Primula.—Hottonia palustris.—Androsace vitalliana.
II. HYBRID PRIMULAS.
The oxlip a hybrid naturally produced between Primula veris and vulgaris.—The differences in structure and function between the two parent-species.—Effects of crossing long-styled and short-styled oxlips with one another and with the two forms of both parent-species.—Character of the offspring from oxlips artificially self-fertilised and cross-fertilised in a state of nature.—Primula elatior shown to be a distinct species.—Hybrids between other heterostyled species of Primula.—Supplementary note on spontaneously produced hybrids in the genus Verbascum.
III. HETEROSTYLED DIMORPHIC PLANTS—continued.
Linum grandiflorum, long-styled form utterly sterile with own-form pollen.— Linum perenne, torsion of the pistils in the long-styled form alone.—Homostyled species of Linum.—Pulmonaria officinalis, singular difference in self-fertility between the English and German long-styled plants.—Pulmonaria angustifolia shown to be a distinct species, long-styled form completely self-sterile.— Polygonum fagopyrum.—Various other heterostyled genera.—Rubiaceae.—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.
IV. HETEROSTYLED TRIMORPHIC PLANTS.