. La pollinisation des fleurs de manuel : d'après Hermann Mu ?ller 'le travail de la fécondation des fleurs par les insectes" . La fertilisation des plantes. Descendez-PLACES DANS LES FLEURS 99 Sprengel décrit ces formes de "faux nectar de fleurs." Les observations de Charles Darwin et Herm. Miiller ont prouvé que les visiteurs de l'alésage dans le tissu cellulaire juteux de nos espèces d'Orchis, et donc de se procurer la nourriture. Miiller a également montré que très probablement quelques visiteurs de Cytisus Laburnum et Erythraea centaurium alésage pour sap qui est enfermé dans les fleurs, et il n'est pas improbable que l'industrieuse plus b

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. Handbook of flower pollination : based upon Hermann Mu?ller's work 'The fertilisation of flowers by insects' . Fertilization of plants. ALIGHTING-PLACES IN FLOWERS 99 Sprengel described such forms as 'false nectar flowers.' The observations of Charles Darwin and Herm. Miiller have proved that the visitors bore into the juicy cellular tissue of our species of Orchis, and thus procure nourishment. Miiller has also shown that very probably some visitors of Cytisus Laburnum and Erythraea Centaurium bore for sap that is enclosed in the flowers, and it is not improbable that the more industrious bees and Lepidoptera may pierce many other flowers for the same purpose, using the tip of their proboscis as a boring-instrument. It is a fact that Lepidoptera, which are only able to feed on fluids, not infrequently remain for a considerable time on pollen flowers with the proboscis sunk in their bases, e.g. Helianthemum alpinum (Herm. Miiller, ' Alpenblumen, ' p. 162), so that we are justified in assuming that these insects bore for sugary juice. In other plants, e. g. in species of Pinguicula, instead of nectar the visitors find little knobs distended with sap, that seem to offer them nourishment. In species of Verbascum, Hyperi- cum, and Lysimachia, club-shaped glandular hairs on the filaments, or similar hairs on the inner side of the petals, appear to supply material for moistening the pollen, and causing it to stick. Such peculiarities of particular flowers will be dealt with at length in the second volume of this work. Besides pollen, nectar, and juices obtained by boring or gnawing, many insects take from the flowers they visit other parts not originally destined for this purpose. Numerous flower-visiting beetles (Chrysomelidae, Lamellicornia, Curculionidae) devour stamens, petals, or other floral parts, and thus inflict almost unmixed injury, since they only exceptionally confer the benefit of cross-pollination. In individual. Fig. 16. Alighiing-Pliicts. (l) Pedicularis