An experimental inquiry into the cause of the ascent and descent of the sap : with some observations upon the nutrition of plants, and the cause of endosmose and exosmose / by G. Rainey.

  • Rainey, G. (George), 1801-1884.
Date:
1847
Catalogue details

Licence: Public Domain Mark

Credit: An experimental inquiry into the cause of the ascent and descent of the sap : with some observations upon the nutrition of plants, and the cause of endosmose and exosmose / by G. Rainey. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    a previously finished joint, but afterwards communicates with it in the manner before described, and thus a vessel is increased in length by the successive addition of new joints. At first, the marking of many of the recently formed vessels is so faint, as not to be distinguishable, excepting by the best lenses of a high magnifying power, but it gradually increases in distinctness as the spiral fibre becomes developed. In petals, and in the expansions of thin leaves, such as admit of being rendered transparent by acetic acid, the cells and vessels are too small to shew distinctly the manner in which the larger vessels acquire their diameter j this can be best seen in the soft immature stems of herbaceous vegetables. Plate ii. Fig. 10 is the repre- sentation of a very thin transverse section of the stem of the Solanum Tuberosum dried, and preserved in Canada Balsam, showing that the wall of a vessel is formed by the union of the external thickened wall of the surround- ing cells. Plate ii. Fig. 12 exhibits vessels seen lengthwise in different states of development, taken from the Solanum Tuberosum, shewing how they acquire their diameter by the union of cells (called cambium cells). The walls of these cells are seen first to unite longitudinally, forming vessels of various sizes, the diameter of each depending upon the number of cells thus united: next the spiral fibre can be observed to become developed in the walls of the cells; prior to which, these walls are remarkably thin and diaphonous. The formation of this fibre seldom commences simultaneously in all the cells occupying the' entire circumference of a vessel, but on the contrary, its development is seen to be much more advanced on some