. Handbook of flower pollination : based upon Hermann Mu?ller's work 'The fertilisation of flowers by insects' . Fertilization of plants. COMPOSITAE 579 hairs, remain permanently apposed, and project far out of the florets, their only function being to brush the pollen-masses out of the anther-cylinder. Here, there- fore, we have a third different kind of stock; the two others have already been described. The pollen-grains are white, roundish to ellipsoidal, up to 37 /x long and 31 /* broad, with long spines adapted to secure adhesion to the stigmatic Fig. 194. Petasites albus, Gaer
. Handbook of flower pollination : based upon Hermann Mu?ller's work 'The fertilisation of flowers by insects' . Fertilization of plants. COMPOSITAE 579 hairs, remain permanently apposed, and project far out of the florets, their only function being to brush the pollen-masses out of the anther-cylinder. Here, there- fore, we have a third different kind of stock; the two others have already been described. The pollen-grains are white, roundish to ellipsoidal, up to 37 /x long and 31 /* broad, with long spines adapted to secure adhesion to the stigmatic Fig. 194. Petasites albus, Gaertn. (after Herm. Muller). A. Sexual floret from a female head {ov, raptured ovary with projecting ovule). A'. Upperpart of a corolla. B. Nectar-secreting floret of the female head. C. Ditto, split longitudinally. D. Sexual nectar-secreting floret from a male head. 5". Part of a stylar branch from the same floret. F. Degenerate floret from a male head. (./4-Z? and F y. T, E y. 80.) a, anther-cylinder; CO, corolla;,;?, filament; gr, style; n, nectary; ov. ovary. Visitors.—The following were recorded by the observers and for the localities stated,— Knuth (Kiel), the honey-bee. Warnstorf (Ruppin), do. Wiistnei (Alsen), the humble-bee Bombus terrester L. Alfken (Bremen), 2 humble-bees—i. Bombus lucorum Z. 5; 2. B. pratorum L. 5. MacLeod (Belgium), 5 bees, 3 Lepidoptera, and small flies. Burkill (Yorkshire coast), a midge (Chironomus sp.), a bug (Hetero- cordylus sp.), and 2 bees (Andrena gwynana K. 5, and Bombus terrester Z.), skg. p p 2. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Knuth, Paul, 1854-1899; Knuth, Paul, 1854-1899; Mu?ller, Hermann, 1829-1883; Ainsworth Davis, J. R. (James Richard), 1861-1934. Oxford : Clarendon Press
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Keywords: ., bookcentury1900, bookdecade1900, bookpublisheroxfor, bookyear1906
