WHEAT 59 



fat, phosphateides, starch, acids, betamin and sugar. So far, Kondo 

 and Gorin have been unable to isolate from rice bran any individual 

 chemical to which the therapeutic effect of the bran could be ascribed. 



Wheat Starch usually occurs in very hard, somewhat elongated 

 and columnar or irregular masses, varying from 1 to 3 cm. in length. 

 The starch grains are more or less rounded or flattened-circular, and 

 depending upon the surface presented to view under the microscope, 

 appear circular or elliptical in outline (Fig. 20) ; they vary from 0.015 

 to 0.035 mm. in diameter and are without distinct markings except 

 when heated or treated with dilute acid or alkaline solutions. When 

 viewed under the micropolariscope the grains do not show a distinct 

 cross, except when viewed on edge, and the play of colors when the 

 selenite plate is used is scarcely discernible. Wheat starch does not 

 agglutinate on mixing with water as wheat flour does. 



Wheat Flour. Agglutinates with water (distinction from wheat 

 starch) ; few tissues of wheat grain. 



Wheat Middlings are grayish-white and in addition to the char- 

 acteristic starch grains there are numerous fragments of tissues, as 

 the thick-walled polygonal cells of the endosperm, which contain 

 small aleurone grains and have a more or less distinct nucleus; the 

 cells of the embryo containing aleurone grains and fixed oil; and the 

 tissues of the pericarp. The latter include unicellular hairs, which 

 are 0.5 to 1 mm. in length and 0.015 to 0.025 mm. in diameter, have a 

 sharply pointed summit and rounded base, and a narrow lumen, 

 which is but 0.001 to 0.002 mm. wide; a layer of tangentially-elon- 

 gated cells from 0.100 to 0.200 mm. long and 0.015 to 0.025 mm. in 

 diameter, which are slightly thickened and with simple pores; and 

 running across the latter are a number of more or less isolated vermi- 

 form cells with rounded ends (Fig. 21). 



Wheat middlings which have been kept for some time acquire an 

 odor suggestive of elm bark or fenugreek. It is extensively used in 

 veterinary medicine as a basis for the inclusion of bitter tonic sub- 

 stances. It has also been extensively used in adulteration of spices, 

 foods and powdered drugs. 



Wheat Bran is said to be sometimes adulterated with " inner 

 coffee hulls," which consist of the inner tissues of the pericarp of 

 the coffee fruit, and are readily detected by the fragments of palisade 

 cells and the somewhat elongated, narrow, sclerenchymatous fibers 

 which cross one another. 



Wheat Germ. The material known as wheat germ was formerly 

 a waste product of the flour mills, or used only as a fodder, but 

 recently it has been utilized in the forms of certain kinds of bread and 



