The microscope and some of the wonders it reveals / by W. Houghton.

  • Houghton, W. (William), 1829?-1897.
Date:
[1871?]
Catalogue details

Licence: Public Domain Mark

Credit: The microscope and some of the wonders it reveals / by W. Houghton. Source: Wellcome Collection.

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    tained therein. Starch is the most generally diffused substance, except protoplasm,* met with in vegetable cells; it occurs in all classes of plants, except funguses. It can always be detected by the application of iodine, which immediately turns the granules blue. I should recommend you to make yourself acquainted with Fig. 4.—Section of Potato, showing Cells and Starch Granules. various forms of starch-granules of several common plants, such as wheat, rice, Indian corn, and arrow- root. It is supposed by some microscopists that the structure of a starch-granule is composed of a series of concentric shells or layers, which are firm as they approach the outside wall, but are less dense and more full of water as they approach the centre or nucleus. The granules may be isolated from the cells by macerating slices in water for a few days. * The name is applied to the nearly colourless gr.inular ^^scid substance, nitrogenous in nature, which constitutes the formative matter in the cells. From irpuror and n-Xatr/xa, “ form.”
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