Introduction to structural and systematic botany, and vegetable physiology, : being a 5th and revedof the Botanical text-book, illustrated with over thirteen hundred woodcuts . ng it all theharder for its struggles, and commonly depriving it of life. Afterall movement has ceased within, the trap slowly opens, and is readyfor another capture. Why this plant catches insects, we are unableto say; and as to the mechanism of the movement it is no more andno less explicable than the much slower movements of ordinaryleaves in changing their position. FIG. 297. A plant of Dionaea muscipula, reduced in
Introduction to structural and systematic botany, and vegetable physiology, : being a 5th and revedof the Botanical text-book, illustrated with over thirteen hundred woodcuts . ng it all theharder for its struggles, and commonly depriving it of life. Afterall movement has ceased within, the trap slowly opens, and is readyfor another capture. Why this plant catches insects, we are unableto say; and as to the mechanism of the movement it is no more andno less explicable than the much slower movements of ordinaryleaves in changing their position. FIG. 297. A plant of Dionaea muscipula, reduced in size. 298. Three of the leaves, ofnearly the natural size ; one of them open, the others closed. AS ASCIDIA OR PITCHERS. 169 302. Ascidia or Pitchers, or tubes open at the summit, representanother remarkable form of leaves. These occur in several plantsof widely different families. If we conceive the margins of thedilated part of the leaf of Dionasa to curve inwards until they meet,and cohere with each other, there would result a leaf in form notunlike that of Sarracenia purpurea, the common Pitcher-plant orSidesaddle Flower of the Northern United States (Fig. 300). So. the tube or pitcher has been supposed to answer to the petiole, andthe hood at the summit to the blade. And this view is strengthenedby a Pitcher-plant of the same family (Heliamphora, Fig. 299),discovered by Mr. Schomburgk in the mountains of British Guiana,in which the pitcher is not always completed quite to the summit,and the hood is represented by a small concave terminal the curious Nepenthes (Fig. 301), the petiole is first dilated intoa kind of lamina, then contracted into a tendril, and finally dilatedinto a pitcher, containing fluid secreted by the plant itself; the orificebeing accurately closed by a lid, which from analogy was supposed torepresent the real blade of the leaf. The study of the development,however (recently made by Dr. Hooker), does not confirm thishypothesis. The whole pi
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Keywords: ., bookauthorgra, bookcentury1800, bookdecade1860, booksubjectbotany
