Lectures on the physiology of plants . FIG. ^^o.—Aristolochta Clctiiatitis. Portion of stem st, withpetiole *, in the axil of which are flowers of various ajfes. i, i youngand as yet unfertilised flowers ; flowers which have been fertilisedand bent downwards ; k flask-like enlargement of the fluwer-tube r;ythe inferior ovaries (nat. size).. Fig. 451.—Aristolochia CUmatttis. Flowers in loHgitudinal section; A before, and ß after fertilisation(enlarged—see text). still receptive stigma the pollen it has brought with it. While the above changesare going on in the interior of the flower, the l
Lectures on the physiology of plants . FIG. ^^o.—Aristolochta Clctiiatitis. Portion of stem st, withpetiole *, in the axil of which are flowers of various ajfes. i, i youngand as yet unfertilised flowers ; flowers which have been fertilisedand bent downwards ; k flask-like enlargement of the fluwer-tube r;ythe inferior ovaries (nat. size).. Fig. 451.—Aristolochia CUmatttis. Flowers in loHgitudinal section; A before, and ß after fertilisation(enlarged—see text). still receptive stigma the pollen it has brought with it. While the above changesare going on in the interior of the flower, the latter, moreover, alters its long as the stigma in the young flower is still receptive, the pedicel is erect,and the perianth open outwards (Fig. 450 i, i,), presenting to the flies a hospitablyopen door; but as soon as they have accomplished the j)ollination of the stigma,the pedicel bends sharply downwards at the base of the ovary, and when theflies, again laden with pollen, have flown away from the flower, the banner-Hke 794 LECTURE XLV. lobe of the corolla {B, Fig. 451) closes over the mouth of the throat, stoppingthe entrance to the flies, which have now nothing more to do here. (2) Flowers with simultaneous dehiscence of stigmas and anthers, but inwhich self-pollination is rendered impossible or difficult by the po
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectplantph, bookyear1887
