. L'origine de structures florales : grâce à la lutte contre les insectes et d'autres organismes. Les plantes ; fleurs ; Fleurs. 134 LA STRUCTURE DES FLEURS. Dans de nombreux cas, la capacité de la fleur se limiter à son bon les visiteurs, et en même temps d'exclure les mauvaises, est un résultat commun des différenciations qui ont eu lieu. Ainsi, un tube de forme allongée, comme dans l'Onagre, et dans certaines espèces de Narcisse, etc., est une conséquence directe de l'adaptation et à la longue proboscides de lépidoptères, et à mesure que le tube est allongé de sorte qu'il n'interdit l'entrée d'insectes, court-tongued ou o

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. The origin of floral structures : through insect and other agencies. Plants; Flowers; Flowers. 134 THE STRUCTURE OF FLOWERS. In many cases the capability of the flower to restrict itself to its proper visitors, and at the same time to exclude the â wrong ones, is a common result of the differentiations which have taken place. Thus, an elongated tube, as in Evening Primrose, and in some species of Narcissus, etc., is a direct result of and adaptation to the long proboscides of Lepidoptera, and in proportion as the tube is elongated so does it prevent the ingress of short-tongued insects, or of those with short proboscides. Apart, however, from such and other general results of adaptations, whereby flowers have become, for example, irregular, and consequently their insect visitors are more and more restricted in number, there are innumerable out- growths of various kinds which act as special obstructions to the entry of small insects which would not be able to pollinate the flower. Thus, while many regular flowers, such as Gentians, have developed horizontal hairs all round the entrance to the tube of the corolla. Honeysuckle and Veronica Chamcedrys, which are irregular and approached from one side only, have developed them in the anterior side alone. In Amaryllis belladonna Kemer describes and figures (Fig. 41) a one-sided flap growing out of the perianth, and so folded as to famish a very small orifice for the entrance of a proboscis. There is no such growth on the anterior side, but only on that one, the posterior, which is probed by an insect. In Gentiana Bavarica there are Fig. 41.âBase of flower of .^mo- , , , , ., ryttis showing honey-protector tooth-like processes at the entrance of (after Eerner). _n j i i ⢠i . t , > t the tube, which remind one of the appendages to the corolla of some of the Silenece. Monotropa glabra and Daphne Blagayana agree in having a large circular. Please note that these images are extracted from scanned page images that may hav

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