Vegetable organography; or, an analytical description of the organs of plants / by Aug. P. de Candolle. Translated by Boughton Kingdon.

  • Candolle, Augustin Pyramus de, 1778-1841.
Date:
1839-1840
Catalogue details

Licence: Public Domain Mark

Credit: Vegetable organography; or, an analytical description of the organs of plants / by Aug. P. de Candolle. Translated by Boughton Kingdon. Source: Wellcome Collection.

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    Section VI. Of Reticulated Vessels. This form of vessel (PL 2, fig. 7 a,) is extremely rare in nature, and has been studied the least of all. Kieser has only discovered them in the Balsam and the Nasturtium {Tropœolum) : he suspects their existence in other plants of a loose texture. According to this observer, these ves¬ sels are owing to the spiral or annular fibres which compose the tracheæ, or striped vessels, anastomosing unequally together, and leaving between them open spaces or oblong holes. They never attain, according to him, the size of dotted vessels, and are often ramified ; they are more frequent in the root than in the stem. Section VII. General Considerations on the Structure of Vessels. I have described, in the preceding sections, the usual forms which the vessels of plants present under the microscope ; and I have intentionally avoided confusing these descriptions with any hypothetical or even theoretical ideas. It remains for us now to examine what are the modifications of which these forms are susceptible ; and thence to deduce, if possible, the relation of these different vessels with one another, and their true nature. Hedwig was the first to treat of these delicate ques¬ tions in his Programme upon Vegetable Fibre : he