CHAPTER II.
GENERAL OBSERVATIONS AND CONCLUSIONS.
Article I.—Regions where Cultivated Plants originated.
In the beginning of the nineteenth century, the origin of most of our cultivated species was unknown. Linnæus made no efforts to discover it, and subsequent authors merely copied the vague or erroneous expressions by which he indicated their habitations. Alexander von Humboldt expressed the true state of the science in 1807, when he said, “The origin, the first home of the plants most useful to man, and which have accompanied him from the remotest epochs, is a secret as impenetrable as the dwelling of all our domestic animals.... We do not know what region produced spontaneously wheat, barley, oats, and rye. The plants which constitute the natural riches of all the inhabitants of the tropics, the banana, the papaw, the manioc, and maize, have never been found in a wild state. The potato presents the same phenomenon.”[2178]
At the present day, if a few cultivated species have not yet been seen in a wild state, this is not the case with the immense majority. We know at least, most frequently, from what country they first came. This was already the result of my work of 1855, which modern more extensive research has confirmed in almost all points. This research has been applied to 247 species,[2179] cultivated on a large scale by agriculturists, or in kitchen gardens and orchards. I might have added a few rarely cultivated or but little known, or of which the cultivation has been abandoned; but the statistical results would be essentially the same.
Out of the 247 species which I have studied, the old world has furnished 199, America 45, and three are still uncertain.
No species was common to the tropical and austral regions of the two hemispheres before cultivation. Allium schœnoprasum, the hop (Humulus lupulus), the strawberry (Fragaria visca), the currant (Ribes rubrum), the chestnut (Castanea vulgaris), and the mushroom (Agaricus campestris), were common to the northern regions of the old and new worlds. I have reckoned them among the species of the old world, since their principal habitation is there, and there they were first cultivated.
A great number of species originated at once in Europe and Western Asia, in Europe and Siberia, in the Mediterranean basin and Western Asia, in India and the Asiatic archipelago, in the West Indies and Mexico, in these two regions and Columbia, in Peru and Brazil, or in Peru and Columbia, etc., etc. They may be counted in the table. This is a proof of the impossibility of subdividing the continents and of classing the islands in well-defined natural regions. Whatever be the method of division, there will always be species common to two, three, four, or more regions, and others confined to a small portion of a single country. The same facts may be observed in the case of uncultivated species.
A noteworthy fact is the absence in some countries of indigenous cultivated plants. For instance, we have none from the Arctic or Antarctic regions, where, it is true, the floras consist of but few species. The United States, in spite of their vast territory, which will soon support hundreds of millions of inhabitants, only yields, as nutritious plants worth cultivating, the Jerusalem artichoke and the gourds. Zizana aquatica, which the natives gathered wild, is a grass too inferior to our cereals and to rice to make it worth the trouble of planting it. They had a few bulbs and edible berries, but they have not tried to cultivate them, having early received the maize, which was worth far more.
Patagonia and the Cape have not furnished a single species. Australia and New Zealand have furnished one tree, Eucalyptus globulus, and a vegetable, not very nutritious, the Tetragonia. Their floras were entirely wanting in graminæ similar to the cereals, in leguminous plants with edible seeds, in Cruciferæ with fleshy roots.[2180] In the moist tropical region of Australia, rice and Alocasia macrorhiza have been found wild, or perhaps naturalized, but the greater part of the country suffers too much from drought to allow these species to become widely diffused.