Botany for ladies or, a popular introduction to the natural system of plants, according to the classification of de Candolle - Softcover

Loudon, Jane Wells

Softcover

ISBN 10: 1235988848 ISBN 13: 9781235988844

Verlag: RareBooksClub.com, 2012

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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1842 Excerpt: ...and then on the other, and will then draw the parts gently a little way asunder, the spiral vessels will be seen distinctly with the naked eye; as though very fine, they are sufficiently strong to sustain the weight of the lower part of the leaf for a short time. Now these vessels are much more conspicuous in some plants than in others; and in some of the inferior plants, such as lichens and fungi, they are wanting altogether. Their presence or absence has therefore been chosen to mark the two great divisions of the Natural System; the Vasculares being those plants which have both vascular and cellular tissue, and the Cellulares being those which have cellular tissue only. The Vasculares are much more numerous than the Cellulares; and they are redivided into subclasses, which it also requires the aid of vegetable physiology to explain. All plants, when in a growing state, require the moisture taken up by their roots to be elaborated, and mixed with air in the leaves before it becomes sap; that is, before it is fit to contribute to their nourishment. Now, when a seed begins to germinate, its root descends into the ground and its plumule, or ascending shoot, rises upwards; but the leaves folded up in the latter are too weak and tender to elaborate the sap; and besides, they cannot act till they are fully expanded, and they want nourishment to give them strength to unfold; the roots are also not sufficiently developed to absorb moisture. To supply the wants of the young plant while it remains in this feeble and imperfect state, a quantity of albumen is laid up in the seed; and it is evident that this substance must be extremely nourishing, as it forms, when ground, what we call flour. The young plant is thus provided with food, till its roots are sufficiently ...

Über diese Auflage

• Verlag: RareBooksClub.com
• Erscheinungsdatum: 2012
• ISBN 10: 1235988848
• ISBN 13: 9781235988844
• Einband: Tapa blanda
• Anzahl der Seiten: 90