The origin of floral structures through insect and other agencies . SENSITIVENESS AND IRRITABILITY OF PLANT ORGANS. IGl ineclite, quil dcsigne sous le nom dYpomcea sensitiva. Letissu membraneux de la corolle campanulee, de cette planteest soutenu par des filets ou par des nervures qui, au moindreattouchement, se plissent ou sHncurvent sinueusement, demaniere a entrainer le tissu membianeax de la corolle,laquelle, de cette maniere, se ferme completement ; ellene tarde point a souvrir de nouveau lorsque la cause quiavait determine sa plicature a cesse dagii\ * M. Dutrochetthen observes that this
The origin of floral structures through insect and other agencies . SENSITIVENESS AND IRRITABILITY OF PLANT ORGANS. IGl ineclite, quil dcsigne sous le nom dYpomcea sensitiva. Letissu membraneux de la corolle campanulee, de cette planteest soutenu par des filets ou par des nervures qui, au moindreattouchement, se plissent ou sHncurvent sinueusement, demaniere a entrainer le tissu membianeax de la corolle,laquelle, de cette maniere, se ferme completement ; ellene tarde point a souvrir de nouveau lorsque la cause quiavait determine sa plicature a cesse dagii\ * M. Dutrochetthen observes that this phenomenon is in no way essentiallydifferent from the closing of the corolla of Convolvulus, towhich Ypomasa is nearly allied, when it passes into the sleep-ing state, as does the calyx or perianth of the coronata exhibits a curious and rapid movement. a i c Fig. i9.—Lopezia (after Hildebrand). (For description, 6ee text.) in a staminode. Miiller thus describes it: f In each flowerthere is present one perfect stamen ; a second, standingimmediately below, is reduced to a spathulate leaf, whosetwo halves fold upwards, and, in the first stage, projectinghorizontally from the flower, inclose the anther of the perfectstamen (Fig. 48, a). The stalk of the spathulate leaf has anelastic tension do^vnwards (6) ; the filament of the stamenan elastic tension upwards (6), so when an insect alights onthe projecting spoon-shaped blade, as the only convenient * Recherches Anatomiques et Thysiolngiques sur la Structure Intimedes Animaux et des Vegetaux et sur leur Motility, 1824, p. Fertilisation, etc., p. 265. 162 THE STRUCTURE OF FLOWERS. spot from whicli to reach two drops of honey that seem torest upon a knee-shaped bend in the upper petals (a), the leafsprings downwards (b), and the stamen is set free and fliesupwards, dusting the low^e
Size: 2576px × 970px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1880, booksubjectfertili, bookyear1888
