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rings but show in most cases a well developed hilum, which is at times star-shaped or like an irregular cross, while at other times it has the appearance of a circular depression. The maize starch granular is a type of the angular, as the wheat is of the sphere or spheroid form. The characteristic appearance of maize starch kernels is shown in the accompanying Fig. 27. Viewed with polarized light the starch grains of Indian corn present deep, well marked crosses, which divide each grain into four distinct parts as shown in Fig. 28. It is interesting to note that the angularity of maize starch is greatly influenced by the hardness of the kernels from which the grains are taken. The hard varieties, such as popcorn, have very angular grains while those from soft varieties have a great many almost spherical forms.

Fig. 28.—Starch Grains of Indian Corn, under Polarized Light. × 200.—(Courtesy of Bureau of Chemistry.)

Maize Flour (Corn Meal).—Formerly the maize kernel was ground between stones, bolted to remove the bran, and the maize flour or corn meal thus produced used directly as a human food. Modern milling operations have changed the method of producing maize flour so that not only is the outer bran removed but also, to a large extent, the germ itself, thus diminishing the quantity of fat in the prepared meal. This is notably true of the maize flour which is prepared for exportation. Leaving in the flour such a large quantity of fat tends to produce rancidity during shipment. To avoid any change of a deleterious nature which the flour may undergo during shipment,