. Field crops for the cotton-belt. Agriculture. 312 FIELD CROPS FOR THE COTTON-BELT The greater portion of the wheat grain consists of endo- sperm or starch cell? which form the chief constituent of wheat flour. The ratio of embryo to endosperm is about as one to thirteen. The embryo is composed essentially of two parts, viz., the miniature plant known as the veg- etative portion, and the absorbent organ, known as the scutellum, which on the germination of the seed, trans- fers the substance of the endosperm to the embryo for its nourishment. Surrounding the endosperm and em- bryo is a single
. Field crops for the cotton-belt. Agriculture. 312 FIELD CROPS FOR THE COTTON-BELT The greater portion of the wheat grain consists of endo- sperm or starch cell? which form the chief constituent of wheat flour. The ratio of embryo to endosperm is about as one to thirteen. The embryo is composed essentially of two parts, viz., the miniature plant known as the veg- etative portion, and the absorbent organ, known as the scutellum, which on the germination of the seed, trans- fers the substance of the endosperm to the embryo for its nourishment. Surrounding the endosperm and em- bryo is a single layer of aleurone cells known as the aleurone layer, which makes up about eight per cent of the weight of the grain. Just outside of and surrounding the aleurone layer is a single layer of col- lapsed cells called the tegmen or nu- cellus. This is in turn surrounded by the testa, which covering contains most of the coloring matter of the Fig. 53. — Cross-sec- tion and transverse section of grain of wheat. Below: transverse section of an unripe grain. pericarpT (2)^outer This Coloring matter may vary from JTer^St'e^gum^int; '^^^ P^^^^ shades of yeUow through am- ber to a deep red, and gives the grain its characteristic color so often used in the classification of wheat varieties. The three layers above described are inclosed in the pericarp or outside covering, which corresponds to the pod in the pea. The nucellus, testa and pericarp con- stitute what is commonly spoken of as wheat bran. The wheat grain is very variable as regards size, color, hardness, shape, weight, and composition, all of these char- (4) remains of nu- cellus; (5) aleurone cells; (6) starch Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Morgan, James Oscar. New York, The Macmillan company
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectagriculture, bookyear
