. Elements of botany. Plants. FEKTILIZATION. 163 honey. Those flowers which secrete nectar do so by means of nectar-glands, small organs whose structure is something like that of the stigma, situated usually near the base of the flower, as shown in Fig. 145. Sometimes the nectar clings in droplets to the surface of the nectar-glands ; sometimes it is stored in little cavities or pouches called nectaries. The pouches at the bases of columbine petals are among the most familiar of nectaries. 201. Odors of Floivers.—The acuteness of the sense of smell among insects is a familiar fact. Flies buzz
. Elements of botany. Plants. FEKTILIZATION. 163 honey. Those flowers which secrete nectar do so by means of nectar-glands, small organs whose structure is something like that of the stigma, situated usually near the base of the flower, as shown in Fig. 145. Sometimes the nectar clings in droplets to the surface of the nectar-glands ; sometimes it is stored in little cavities or pouches called nectaries. The pouches at the bases of columbine petals are among the most familiar of nectaries. 201. Odors of Floivers.—The acuteness of the sense of smell among insects is a familiar fact. Flies buzz about the wire netting which covers a piece of fresh meat or a dish of syrup, and bees, wasps, and hornets will fairly besiege the window-screens of a kitchen where preserving is going on. Many plants find it possible to attract as many insect-visitors as they need without giving off any scent, but small flowers, like the mignonette, and night- blooming ones, like the four-o'-clock ^ ^ , ^. , ° ,' . Fig. 145. — stamens and Pistil and the evening primrose, are sweet- of the Grape (magnified),with scented to attract night-flying moths. ^ lioney-gland between each "^ ./ e. pg^jj, q£ stamens. It is interesting to observe that the majority of the flowers which bloom at night are white, and that they are much more generally sweet-scented than flowers which bloom during the day. A few flowers are carrion- scented (and purplish or brownish colored) to attract flies. 202. Colors of Flowers. — Flowers which are of any other color than green display their colors to attract insects, or occasionally birds. The principal color of the flower is most frequently due to showy petals, sometimes, as in the marsh marigold, it belongs to the sepals, and not infrequently, as in some cornels and Euphorbias, the involucre is more brilliant and conspicuous than any part of the flower strictly Please note that these images are extracted from scanned page images that may have been
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectplants, bookyear1896
