CEREAL GRAINS of several kinds are culti vated for food. The seeds of all the graminele, those of the darnel alone excepted, are capable by cultivation of becoming alimentary. The value of grains, generally speaking, is directly as the size of the caryopsis, and inversely as the thick ness of the pericarp. When the grain abounds in perisperm, it is heavy ; when the envelope is thick, the grain is, on the contrary, light, thus :— 100 seeds of wheat weighed 4'50 grains. 100 „ barley „ 3'85 „ 100 ,, rye „ 260 „ 100 „ oats 2'50 „ The chemical composition of the grain influences materially the quality of the resulting bread. If the gluten be absent, no fermentation takes place in the dough ; if the gluten be in excess, the bread is heavy and acid. Wheat flour may be considered the type of all that is suitable for alimentary purposes, and in the degree of deviation from this standard consists the inferiority of the other grains. The grains or ears of nearly all the cereal grasses are subject to diseases resulting from at tacks of parasitic fungi, animalculm, and insects. The liability of the seeds of grasses to parasitic infection is explained by the large amount of nitrogenized matter contained in them, and to their softness of texture ; and some of the diseases occasion the greatest injury to the agriculturist.
Little is known as to the native countries of the cereal grains. The prevalence of particular grains in the earth's zones and continents, has resulted not alone from climate, but has been determined by the civilisation, industry, and traffic of the people, and often by historical events. Without cultivation, all the cereals degenerate. As they now exist, they seem to have been greatly improved from their natural state. Wheat has five, six, or seven distinct species, barley three, and oats two, three, or four. In the scuth and cast of Asia, the following grains belonging to the grasses (Pani cacem or Graminacem) are the more largely culti vated :— Rajputs, Gouri seems to he the analogue of Ceres, and on the festival of the Ahairea, or Muhurat ka Shikar, they hunt, slay, and eat the wild boar.