Popular Science Monthly/Volume 14/November 1878/Plants and the Peopling of America

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I HAVE spent some years as a botanist in the tropics of both hemispheres, and in the mean time have studied pretty thoroughly the tropical domesticated plants. In America and in Asia the principal domesticated tropical plants are represented by the same species; for instance, Manihot utilissima, whose roots yield a fine flour, the tarro (Colocasia esculenta), the Spanish or red pepper (Capsicum annuum), which is in far more general use than the black pepper, and whose numerous domestic varieties justify the inference that it has been cultivated from a very early period. This inference is still more valid in the case of the banana (Musa paradisiaca), called also the pisang, from which Musa sapientum is not specifically distinguishable; its fruits, in the cultivated state, are always seedless, and the varieties of the plant far surpass in number those of our apples and pears. Other cultivated plants found in both hemispheres are the tobacco, maize, cocoanut—the American origin of none of which is at all proved; then there is the tomato (Lycopersicum esculentum), and the cultivated bamboo, in which among millions of specimens hardly one has flowers. Thus the bamboo is not propagated by means of seed any more than is the tarro, the banana, the sweet-potato, or paritium. Of fruit-trees common to the Old and New Worlds I would further name the guava (Psidium guava), the melon-tree (Carica papaya), and the mango-fruit (Mangifera Indica). Finally I may name Paritium, tiliaceum, a malvaceous plant hardly noticed by Europeans, but very highly prized by the natives of the tropics. This tree, cultivated everywhere in the East and West Indies, South America, and the Malay Archipelago, supplies to the natives all the cordage they require; but in those countries cordage is not kept in stock as among us. If a rope is needed, a branch is broken off and stripped of its bark; the latter is divided into strips, which are held between the toes and twisted by the hands. When a load is to be carried from one place to another the natives usually secure it with a fresh cord of this kind to both ends of a bamboo carrying-pole. In the cultivated state this malvaceous tree is nearly always sterile, while the paritium-trees, which grow wild in the lagoons of the coast of Farther India, always bear seeds. This rope-tree appears to have existed in America before Columbus's time, for it was at an early period imported thence into the Canaries. What we may only accept as probable concerning this plant we know with certainty concerning the cultivated banana or plantain, which is also seedless. It was generally cultivated in America prior to 1492. Now in what way was this plant, which cannot stand a voyage through the temperate zone, carried to America, to the New World, where it certainly does not grow in the wild state? It must be remembered that the plantain is a tree-like herbaceous plant possessing no easily transportable bulbs like the potato or the dahlia, nor propagable by cuttings like the willow or the poplar. It has only a perennial root which, once planted, needs hardly any care, and yet produces the most abundant crop of any known tropical plant. On the average, a plantain annually bears nearly twenty kilogrammes, and sometimes a hundredweight, of most nutritious fruit, which at the same time possesses a delicious flavor. The stem then dies and the root gives out new shoots. No doubt the American race, closely allied as it is with the Mongolian, carried with it, when it migrated to America, the plantain as a cultivated plant from Asia where it grew wild. The plantain cannot have come from Africa or from Polynesia, where musa is also indigenous, for in that case African or Polynesian characters would exist in the aboriginal population of America. Some writers have supposed that this seedless, herbaceous, cultivated plant must have been introduced into America by shipwrecked seamen, because it can exist only in a tropical climate and in living specimens. But in our geological epoch a party of Mongolians shipwrecked in their primitive craft could never have reached the shores of America alive[2] at any point in the tropical zone, for they would be unprovided with sufficient food, and because the tropical distance between Asia and America is enormous, nearly thrice or four times as great as between Europe and America. Then, seamen are not wont to take living specimens of the plantain on their voyages; and, even if they did, these plants would be consumed as food in case of shipwreck.

Even if we suppose the plants to have escaped this fate, they would surely perish for want of fresh water. An hypothesis which rests on four improbabilities is worth nothing, and we might wager one against thousands of millions that no importation of the plantain into America has ever happened in that wise. The only hypothesis which remains is, that the importation took place while the polar regions enjoyed a tropical climate, and that the plantain was brought by the immigrating Asiatics by way of Kamtchatka and Alaska. This is the more probable, because many other tropical cultivated plants are in like manner propagated, not by seeds, but by "eyes," etc. Now, a cultivated plant which does not possess seeds must have been under culture for a very long period—we have not in Europe a single exclusively seedless, berry-bearing, cultivated plant—and hence it is perhaps fair to infer that these plants were cultivated as early as the beginning of the middle of the diluvial period. Moreover, the hypothesis of an immigration of the Indians via a still tropical Northern Asia and North America is confirmed by their going naked. Had they passed through a climate like that of the Kamtchatka of to-day, they must have worn clothing; and a people that once has acquired that habit never abandons it afterward. Further, it must be observed that the American Indians generally are bad seamen, attempting only coastwise voyages; and this fact also renders the supposition of an oceanic immigration improbable. Whether man was the earliest cultivator of plants is doubtful, for we know of one or two species of ants which also regularly cultivate certain plants. We have, therefore, no reason to doubt that the very early ancestors of the Indians, however barbarous they may have been, cultivated a plant the culture of which is very easy and whose produce is most abundant, for it yields, as Humboldt has shown, on the same area, twenty-five times as large a crop and twenty-five times as much food-value as wheat.

I will consider the only two objections that have hitherto been brought against my hypothesis:

1. The importation of this plant by seamen who would have reached the American coast in their frail canoes, being favored by ocean-currents, is not possible, because within the tropics there is but one ocean current from Asia toward America, namely, the equatorial current; but now this current, strictly speaking, does not touch Asia at all, but has its beginning at a point eastward of the Philippines and the Moluccas. If we make the very bold supposition—for a waste of water 80° wide, or twelve hundred geographical miles, has to be crossed, or two thousand geographical miles from the Moluccas—that such immigration is possible, then Polynesian and not Mongolian races would inhabit America, which is contrary to the facts of the case. 2. Or, supposing an immigration along a line near to the equator, we must presuppose a regular intercourse in prehistoric times between Southern China or Farther India and Central America, so that the later immigrants might make preparation for carrying out with them on a long sea-voyage living plants, as the banana, paritium, bamboo, etc.: for this supposition there is no ground whatever. Besides, many traditions current among various American tribes point to an immigration from the north, while the equatorial current only touches America at Panama.

I have still to meet another objection, namely, that the banana, when man began to cultivate it, must have had seeds (though this is so no longer), and that the seeds only were brought to America at an early period. This is inadmissible, because in that case the plantain must often have reverted to the wild state, like all other seed-bearing tropical fruits. But the plantain does not grow wild, though in tropical America it finds the same conditions of vegetation as in its native country, and hence thrives there. The wild plantain in India has small stony seeds, and is distributed widely by monkeys, bats, and insects. which like the fruit but cannot destroy the seeds. In Asia wild, seed-bearing plantains are usually found growing in groups. In America, which has a much greater area of wilderness, the plantain must have spread far and wide, seeing that it has persisted in the wild state in the far more densely-inhabited East Indies. Therefore, it appears that in America the plantain has always been a seedless, cultivated plant, which can only have been introduced from Asia in preglacial times, through northern zones, for in that way alone was the immigration at all possible.—Ausland.

  1. Translated from the German by Dr. H. Hartogh Heys van Zouteneer.
  2. The Chinese and Japanese are acquainted with the plantain, and possess large ships in which pretty long voyages may be made. In the summer the plantain might live in the temperate zone. It can hardly be doubted that long before Columbus's time the junks of those peoples may have been wrecked on the Pacific coast of America. This seems an objection to the author's views.—Translator.