The future—a near future, I hope—will show what practical importance such a method of treating cereals may have. But we need not speculate about that future. We have already, in the facts mentioned in this chapter, an experimental basis for quite a number of means of improving our present methods of culture and of largely increasing the crops. It is evident that in a book which is not intended to be a manual of agriculture, all I can do is to give only a few hints to set people thinking for themselves upon this subject. But the little that has been said is sufficient to show that we have no right to complain of over-population, and no need to fear it in the future. Our means of obtaining from the soil whatever we want, under any climate and upon any soil, have lately been improved at such a rate that we cannot foresee yet what is the limit of productivity of a few acres of land. The limit vanishes in proportion to our better study of the subject, and every year makes it vanish further and further from our sight.
FOOTNOTES:
[71] The researches of Tisserand may be summed up as follows:
| Year. | Population in millions. | Acres under wheat. | Average crop in bushels per acre. | Wheat crop in bushels. |
| 1789 | 27·0 | 9,884,000 | 9 | 87,980,000 |
| 1831-41 | 33·4 | 13,224,000 | 15 | 194,225,000 |
| 1882-88 | 38·2 | 17,198,000 | 18 | 311,619,000 |
[72] In a recent evaluation, M. Augé-Laribé (L’évolution de la France agricole, Paris, 1912) arrives at the following figures:—
| Years. | Area under wheat. Acres. | Years. | Area under wheat. Acres. |
| 1862 | 18,430,000 | 1900 | 16,960,000 |
| 1882 | 17,740,000 | 1910 | 16,190,000 |
| 1892 | 17,690,000 | — | — |
The average crops for each ten years since 1834 are given as follows:—
| Years. | Crops in bushels. | Years. | Crops in bushels. |
| 1834-43 | 190,800,000 | 1884-95 | 294,700,000 |
| 1856-65 | 272,900,000 | 1896-1905 | 317,700,000 |
| 1876-85 | 279,800,000 | 1906-09 | 333,400,000 |
The wheat crop has thus increased in seventy-five years by 74 per cent., while the population increased only by 20 per cent. For potatoes, the increase is still greater: while 198,800,000 cwt. of potatoes were grown in 1882, the crop of 1909 was already 328,300,000 cwt., the average yield of the acre growing from 148 cwt. in 1882 to 212 cwt. in 1909.
[73] Grandeau, Etudes agronomiques, 2e série. Paris, 1888.