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Page:Popular Science Monthly Volume 56.djvu/734

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POPULAR SCIENCE MONTHLY.

the leaves to that in the underground stem something may be said later in this paper.

In the corn plant the starch is stored chiefly in the grain, and not in the subterranean portions, as in the potato. The granules of the corn starch are much smaller than those of the potato, as indicated by Fig. 2, which is from a camera drawing of a cell from a grain of corn and made to the same scale as Fig. 1. The granules are oval and not much marked with striæ or lines, but chemically the substance is the same in both cases.

Another leading starch is that of wheat, the form of the grains of which is shown in Fig. 3. While somewhat larger than the corn-starch granules, they are not otherwise widely different.

One could scarcely overlook the starch produced by the rice plant, for it feeds more people than the potato, corn, or wheat. The relative size and form of the rice-starch granules are shown in

PSM V56 D0734 Starch granules of wheat and rice.png
Fig. 3.—Starch Granules of Wheat. Fig. 4.—Starch Granules of Rice.

Fig. 4. It is seen that the grains are not large, and with a strong tendency to break up into small angular pieces.

There are almost as many forms of starch as plants producing it, some of them being very odd in shape. Thus the tapioca starch has a characteristic form, as also the sago; but it is not the purpose here to more than call attention to the form in which the substance under consideration is laid down in plants. The student of food adulterations is an expert in the detection of starches, and, with his microscope and skill, is able to decide how much of one kind of starch and how much of another is offered in the product under examination. It is a matter of congratulation that Nature has set herself so strongly against fraud in food stuffs as to record the origin of each grain of starch in the grain itself.

And that brings us to a consideration of that origin. We must accord to plants the exalted prerogative of being the exclusive and universal starch-formers in the world. Whether we note the