This does not, however, represent Europe's total bread requirement, as large quantities of rye bread are used by the inhabitants of several European countries.

188. Yield per Acre.-There is a marked variation in yield per acre of wheat in different countries. It will be seen that the two countries which produce the most wheat have the smallest yield per acre.

Average yield of wheat in bushels per acre, 1894-1900:

Climate apparently has a greater influence in bringing about these differences in yield than either soil or cultural methods, although the latter are important factors. A moderately cool climate with a liberal supply of moisture prolongs the period during which the grain develops, thus favoring the development of the endosperm and thereby increasing the volume weight and the yield per acre. (74, 112)

189. Export of Wheat and Flour.-The world's export of wheat and flour for the half decade 1898-1902 ranged from 347 million (1900) to 444 million (1902) with an average annual exportation of 411 million bushels. During the same period the exportation of wheat and flour from the United States was equivalent to 215 million bushels of wheat per annum, as compared with 155 million bushels the preceding five years, which was thirty-six and thirty-four per cent respectively of the total production. The following table is an estimate of the world's average annual export of wheat and flour for the five years 1898. 1902:1

1 U. S. Dept. of Agr. Yearbook, 1902, p. 770.

The following table gives the exportation of wheat and flour from the United States by customs districts for the year ending June 30, 1902:1

The average annual export price of wheat from United States, 1898 to 1902, inclusive, was 78 cents per bushel; for flour $3.90 per barrel.

More than ninety-eight per cent of the wheat exported from the United States in 1902 was shipped from twenty ports. For the five years, 1898-1902, seven of these ports sending out

1 Commerce and Navigation of United States. Treas. An. Rpt. 1902, Vol. I pp. 496-497

more than ten million bushels annually, held the following rank. New York, New Orleans, Baltimore, Galveston, Boston, San Francisco, Willamette (Ore.). New York was the only port sending out as much as twenty millions annually, and her average annual shipment for the five years given was 29.3 million bushels. Other important ports were, respectively, Puget Sound (Wash.), Philadelphia, Portland and Falmouth (Me.), Superior (Wis.), Chicago and Duluth,1

190. Imports of Wheat.-All the countries which consume more wheat than they produce are situated in Europe, with the exception of the Oriental countries, which have recently begun to take supplies of wheat from North America. The larger part of the export of wheat and flour from the United States is taken by Great Britain and Ireland, the Netherlands, Germany, France and Belgium. Great Britain, as the principal importer of wheat, is the arbiter of its price throughout the world. The demand for wheat by Great Britain has increased rapidly during the past fifty years, through decrease in wheat production, through increase in population and in per capita consumption.

191. Commercial Grades.-Every important wheat market maintains a system of inspection of wheat and other grains. Wheat is bought and sold by grades and all wheat coming into a market is inspected and the grade determined by the inspector and when leaving this market may be inspected again. A specified charge is made for this service. The weight per bushel is determined in every sample, but other considerations help to fix the grade, as plumpness, soundness, freedom from foreign seeds or mixture with a different type of wheat. Aside from the weight per bushel, fixing the grade is largely a matter of judg ment and expertness upon the part of the inspector. The information concerning these grades cannot satisfactorily be

1 U. S. Treas. Dept., Bu. Stat. Statistical Abst., 1902, p. 3.

conveyed to another except by actual practice. The grades vary in different markets to suit the supply and demand at each particular market. The classes and grades recognized by the Board of Railroad and Warehouse commissioners for the inspection of wheat at Chicago are as follows:

Red winter wheat containing a mixture not exceeding five per cent of white winter wheat is classed as red winter wheat. Red winter wheat containing more than five per cent of white wheat is graded according to the quality thereof and classed as white winter wheat. Hard winter wheat corresponds to red winter wheat except that it is of the Turkish variety common throughout the Missouri River Valley. A mixture of Turkish wheat with other varieties of red winter wheat is graded as hard winter wheat. Northern spring wheat must contain at least fifty per cent of hard varieties of spring wheat. A mixture of more than five per cent of white spring wheat in red spring wheat will cause it to be graded white spring wheat. Black sea and flinty fife wheat are in no case graded higher than No. 2 and rice wheat no higher than No. 4. Frosted wheat is not graded higher than No. 4 except that the grade of No. 3 may contain as much frosted wheat as is customary to all wheat damaged in another way. Only a small portion of the wheat of any sort grades No. 1. Most of the wheat dealt in grades No. 2 or No. 3. The following are the rules for grading red winter wheat:

"No. 1 Red Winter Wheat shall be pure Red Winter Wheat of both ligi t and dark colors of the shorter berried varieties, sound, plump and well cleaned.

"No. 2 Red Winter Wheat shall be Red Winter Wheat of both light and dark colors, sound and reasonably clean.

"No. 3 Red Winter Wheat shall include Red Winter Wheat not clean and plump enough for No. 2, but weighing not less than fifty-four pounds to the measured bushel.

"No. 4 Red Winter Wheat shall include Red Winter Wheat, damp, musty or from any cause so badly damaged as to render it unfit for No. 3."

III. HISTORY.

192. Antiquity. The cultivation of wheat is much older than the history of man. Very ancient monuments, much older than the Hebrew Scriptures, show its cultivation already established. The Egyptians and the Greeks attributed its origin to mythical personages. The earliest Lake Dwellers of Western Switzerland cultivated a small-grained variety of wheat as early as the Stone Age. The Chinese grew wheat 2700 B. C., and considered it a direct gift from Heaven. Wheat is one of the species used in their annual ceremony of sowing five kinds of seeds. Chinese scholars believe it to be a native of their country. 193. Original Habitat.-The existence of different names for wheat in the most ancient languages confirms the belief in its great antiquity. It has been asserted that wheat has been found growing wild in Western Asia, but the evidence is not conclusive. The Euphrates Valley is believed by De Candolle to be the principal habitation of the species in prehistoric times. So far as known, wheat was not grown in America before its discovery by Columbus.

194. Reasons for Culture.-Its ease of cultivation; its adaptation to a climate favorable to the beginning of civilization; its quick and abundant return; its ease of preparation for use; its abundant supply of nutritious substance; possibly its rapid improvement under cultivation and the fact of its being paniferous, or possessing that special quality which adapts it above any other grain to the making of light bread, were probably some of the reasons which caused primitive man to begin and continue its