Popular Science Monthly/Volume 25/October 1884/The Origin of Cultivated Plants
|THE ORIGIN OF CULTIVATED PLANTS.|
By M. ALPHONSE DE CANDOLLE.
THE traditions of the ancient peoples, embellished by the poets, have commonly attributed the first steps in agriculture and the introduction of useful plants to some divinity, or at least to some great emperor or inca. Reflection teaches us that this is not probable, and the observation of the agricultural efforts among the savages of our own age indicates that the real facts in the case are quite different. Generally, in the progressive steps that lead to civilization the beginnings are weak, obscure, and narrow. There are reasons why this should be so in agricultural and horticultural initiatives. There are many gradations between the custom of gathering fruits, seeds, or roots in the field and that of regularly cultivating the plants which yield such products. A family may scatter seeds around its home, and the next year seek the same product in the forest. Some fruit-trees may be growing around a house, and we not know whether they have been planted there, or the hut has been built near them for convenience of access to them. Wars and hunting often interrupt efforts at cultivation. Rivalries and jealousies may make one tribe slow in imitating another. If some great personage ordains the cultivation of a plant and institutes some ceremony in demonstration of its utility, it is probably after obscure persons have spoken of it and successful experiments have been made upon it. Previous to such demonstrations adapted to impress the multitude, a shorter or longer period of local and ephemeral trials must have passed. Determining influences were needed to incite these trials, to secure their renewal, and bring them to success. We can easily understand what they were.
The first thing necessary was to have within reach some plant offering qualities desirable to all men. The most backward savages are acquainted with the plants of their own country; but the Australians and Patagonians are examples to show that, if they do not judge them productive and easy to raise, they do not think of putting them under cultivation. Other conditions are quite evident: a climate not too rigorous; in hot countries, freedom from too long drought; some degree of security and fixedness; and, last, a pressing necessity resulting from failure of resources in fishing, hunting, or the production of the nutritious fruits of native plants, such as the chestnut, the date, the banana, or the bread-fruit. When men can live without working, that is what they prefer. Besides, the element of chance in hunting and fishing tempts primitive men—and some civilized ones too—more than do the difficult and regular labors of agriculture. To return to the species which savages may be disposed to cultivate. They find them sometimes in their own country, but frequently they receive them from neighboring people who are more favored by natural conditions than they, or have already entered upon some degree of civilization. Unless a people is cantoned in an island or in some place difficult of access, it will speedily receive those plants discovered elsewhere whose advantageous qualities are evident, and this will divert them from the cultivation of the inferior species of their own country. History teaches us that wheat, maize, the yam, several species of the genus Panicum, tobacco, and other plants—particularly annual ones—became widely diffused before the historical period. These good species encountered and arrested the timid efforts which might have been made here and there with less productive or less agreeable plants. In our own days, we see, in different countries, wheat taking the place of rye, maize preferred to buckwheat, and many grains, vegetables, and economical plants falling into neglect because other species, often brought from a distance, offer more advantages. The disproportion in value is, however, less between plants already cultivated and improved than formerly existed between cultivated plants and quite wild ones. Selection—that grand factor which Darwin has had the merit so fortunately to introduce into science—plays an important part when agriculture is once established; but in every period, and especially in the beginning, the quality of the species is more important than the selection of varieties.
The various causes which favor or oppose the beginnings of agriculture will explain why some regions have been for thousands of years populated by cultivators, while others are still inhabited by wandering tribes. Rice and several legumes in Southern Asia, barley and wheat in Mesopotamia and Egypt, several grain-plants in Africa, maize, the potato, the yam, and the manioc in America, were evidently easily and soon cultivated under the inducements offered by their obvious good qualities and favorable climatical conditions. Centers were thus formed, and hence the most useful species were diffused. In the north of Asia, Europe, and America, the temperature is unfavorable, and the indigenous plants are sparsely productive; but, as the resources of hunting and fishing are available, the introduction of agriculture could be delayed, and the people could do without the valuable species of the South without suffering much. It was otherwise in Australia, Patagonia, and Southern Africa. The plants of the temperate regions of our hemisphere could not reach these countries on account of the distance, and those of the intertropical zone were excluded from them by the excessive drought or the absence of high temperatures. At the same time the native species were miserable in quality. It was not want of intelligence or of security alone that prevented the inhabitants from cultivating them. Their nature also discouraged the effort to such an extent that the Europeans, during the hundred years they have been in these countries, have only attempted the cultivation of a single species, the tetragonia, an inferior green herb. I do not forget that Sir Joseph Hooker has enumerated more than a hundred Australian species that might be used in some way; but, in fact, they have not been cultivated, and they are not cultivated, with all the improved processes which the English colonists possess. This demonstrates the principle I have just announced, that the quality of the species has an influence on the selection, and that there must be real qualities in a wild plant to induce an effort to cultivate it.
Notwithstanding the obscurity that surrounds the beginnings of agriculture in different regions, it is settled that the dates vary exceedingly. One of the earliest examples of cultivated plants is drawn from Egypt, in the shape of a design representing figs in one of the pyramids of Gizeh. The date of the construction of the monument is uncertain; authors vary in assigning it to from fifteen hundred to four thousand two hundred years before the Christian era. If we assign it to two thousand years before Christ, we would have an antiquity of four thousand years for the fig. Now, the pyramids can have been constructed only by a numerous people, organized and civilized to a certain degree, who must consequently have had an established agriculture, going back several centuries, at least, for its origin. In China, twenty-seven hundred years before Christ, the Emperor Chennung introduced a ceremony in which, every year, five species of useful plants were sown—viz., rice, soja, wheat, and two kinds of millet. These plants must have been cultivated for some length of time in some places to have attracted the attention of the emperor at this period.
Agriculture seems, then, to have been as ancient in China as in Egypt. The constant intercourse of the latter country with Mesopotamia justifies us in presuming that cultivation was almost contemporaneous in the regions of the Euphrates and the Nile. Why may it not have been quite as ancient in India and the Indian Archipelago? The history of the Dravidian and Malaysian people does not go back very far, and is very obscure; but there is no reason for presuming that cultivation, particularly on the banks of the rivers, did not begin among them a very long time ago.
The ancient Egyptians and the Phœnicians propagated numerous plants in the region of the Mediterranean; and the Aryan peoples, whose migrations toward Europe began nearly twenty-five hundred or, at latest, two thousand years before Christ, spread many species which had already been cultivated in Western Asia. We shall see, in studying the history of particular species, that some plants were probably already cultivated in Europe and Northern Africa. This is indicated by names in languages that prevailed before the Aryans came: the Finnish, Basque, Berber, and Guanche (of the Canary Islands). The remains, called Kjökkenmöddings, of the ancient habitations of Denmark have, however, as yet furnished no traces of cultivation, and no evidence of the possession of a metal The Scandinavians of that period lived entirely by fishing, hunting, and, perhaps accessorily, on indigenous plants—such as those of the cabbage kind—which were not of a nature to leave traces of themselves in the manure-heaps, and which, perhaps, did not require cultivation. The absence of metals does not imply, in those northern countries, a greater antiquity than the age of Pericles, or even of the best period of the Roman Republic. Agriculture was finally introduced later, after bronze had become known in Sweden, a country then still far from civilized lands. A sculpture of a plow, drawn by two oxen and guided by a man, has been found in the remains of that epoch.
The ancient inhabitants of Switzerland cultivated several plants, some of which originated in Asia, when they had instruments of polished stone, but not of metals. M. Heer has shown that they were in communication with the countries situated to the south of the Alps. They may, in this way, have received cultivated plants from the Iberians, who occupied Gaul before the Celts. In the period when the lake-dwellers of Switzerland and Savoy were in possession of bronze, their cultivated plants were more varied. Apparently, even the lake-dwellers of Italy cultivated fewer species when they had that metal than the people of the lakes of Savoy—a fact which may have been connected with a greater antiquity, or with local circumstances. The remains of the lake-dwellers of Laybach and of the Mondsee, in Austria, also attest a quite primitive agriculture; no cereals have been found at Laybach, and only a single grain of wheat at the Mondsee. So little advanced a condition of agriculture in that eastern part of Europe is in opposition to the hypothesis, based on some words of the ancient historians, that the Aryans sojourned first in the region of the Danube, and that Thrace was civilized before Greece. Notwithstanding this example, agriculture seems to have been generally more ancient in the temperate part of Europe than we would be ready to believe from the accounts of the Greeks, who were disposed, like some modern peoples, to make all progress appear to start from their nation.
In America, if we may judge from the civilizations of Mexico and Peru, which do not go back even to the first centuries of the Christian era, agriculture was not, probably, as ancient as in Asia and Egypt. But the immense dispersion of certain kinds of cultivation—as that of maize, of tobacco, and of the yam—leads us to assign an antiquity of nearly or about two thousand years to it. History fails us in this case, and we have no resource for ascertaining anything about it, except from discoveries in archæology and geology.
- From his new book, "The Origin of Cultivated Plants," recently published in Paris.