Popular Science Monthly, October, 1902: 492-505
THE AMERICAN ORIGIN OF AGRICULTURE.
O. F. COOK.
U.S. DEPARTMENT OF AGRICULTURE.
AGRICULTURAL science so generally appears as a borrower from physics, chemistry, botany or zoology that it has not been expected to furnish facts of use in other lines of investigation. Thus, although it has been known since the sixteenth century that the same series of food plants extended throughout the tropics of both hemispheres, the significance of this is still unappreciated, and ethnologists are still doubtful regarding prehistoric communication across the Pacific. Stranded Japanese junks, Buddhist missionaries, Alaskan land connection and other possibilities of contact have been gravely and minutely discussed while unequivocal evidence of extensive early intercourse lay only too obviously at hand.
The history of agriculture shows a conservatism probably unequaled in any phase of human activity. Not only has no important food plant been domesticated in historic times, but even in the most enlightened communities changes in the culture and use of the food plants and products to which our physical constitutions and domestic customs have become adapted take place with extreme slowness except as they accompany movements of colonization. Remembering this strict self-limitation of man to traditional food materials, it becomes obvious that the possession of the same seedless plants, such as the yam, sweet potato, taro, sugar-cane and banana by the primitive peoples of the islands of the Pacific, as well as by those of the adjacent shores of Asia and America, indicates, with attendant facts, not only an older communication, but an intimate contact or community of origin of the agricultural civilizations of the lands adjacent to the Pacific and Indian Oceans.
The Useful Plants of the Pacific Islands.
Notwithstanding the immense distances by which the tropical islands of the Pacific are separated from the continents and from each other, European discoverers found them already occupied by an adventurous sea-faring people who knew enough astronomy to navigate their frail canoes in these vast expanses of ocean without the assistance of the mariner's compass. The agriculture of the Polynesians was, however, no less wonderful than their seamanship, and was certainly not less important to them, since the coral islands of the Pacific are not only deficient in indigenous food plants and animals, but the natural conditions are distinctly unfavorable to agriculture.
The whole surface of these flat coral islands is like the clean white-sanded floor of an old English kitchen. The cocoanut tree springs up everywhere, but in the spots where yams and taros are grown the sand is hollowed out, and a pit formed, from one to two hundred yards long, and of varying width, into which decaying cocoanut leaves and refuse are thrown, till a rich soil is formed.*
*Moresby, 'Discoveries and Surveys in New Guinea,' p. 73, London, 1876. The volcanic islands of Polynesia have, of course, rich soil, but they shared the deficiency of native food-plants from which non-agricultural people could have secured a permanent food supply.
|†'The Origin and Distribution of the Cocoa Palm,' Contributions from the U. S. National Herbarium, Vol. VII., No. 2. Washington, 1901.|
It is certain, however, that among the Polynesians the cocoanut is a cultivated plant no less than the yam, taro, sweet-potato, sugar-cane, banana, breadfruit and numerous other species found in use throughout the tropical islands of the Pacific. Moreover an especial interest attaches to the cocoanut in that there are adequate botanical reasons† for believing that it originated in America, the home of all related palms.
|‡Bull. No. 95, Office of Experiment Stations, U. S. Dept. Agri., p. 33.|
The agricultural achievements of the Polynesians become the more impressive when we reflect that so many of their cultivated species were not propagated from seeds, but from cuttings. To survive the long voyages in open canoes, these must have been carefully packed, kept moist with fresh water and protected against the salt spray. In the present state of botanical knowledge the number of species thus introduced and distributed by the Polynesians is necessarily uncertain. Many of the economic plants were native in some of the islands of the Pacific, though their constant presence among the peoples of widely separated archipelagos gives sufficient reason for including them in the list of twenty-four species, which Professor Hillebrand‡ believes to have been brought to the Hawaiian Islands by the early Polynesians. This number, however, must be greatly increased, since there were many varieties of the sweet potato, taro, sugar-cane and banana. Moreover the Hawaiian group is scarcely more than subtropical in climate, and lacks numerous seedless sorts of the breadfruit, yam, taro and other plants of the equatorial belt of islands, so that a complete enumeration of the species and varieties carried by the Polynesians would include nearly a hundred.
|*Even the cosmopolitan tropical weeds are worthy of careful study from this standpoint. After excluding aquatic, swamp-land and strand species, Seeman found 64 genuine weeds in Fiji, of which 48 were common to America, while only 16 were held to be Old World species.|
A detailed study of the distribution, names, cultures and uses of these species and varieties of tropical economic plants would yield information of much value from the agricultural standpoint, but of even greater significance is its bearing upon the origins and migrations of the ancient agricultural peoples of the Tropics.* At present we have only incomplete and scattered data collected incidentally by missionaries, travelers and professional botanists who did not appreciate their opportunities from the agricultural point of view. But even these miscellaneous facts are often of unexpected interest. Thus, we know that in Central America the use of leguminous shade-trees in cacao plantations was adopted by the Spanish colonists from the natives who furnished even the name 'mother of cacao,' by which the species of Erythrina and other leguminous trees are still known in Spanish America. The Indians, of course, were not aware that the roots of the Leguminoseae develop tubercles for the accommodation of bacteria able to fix atmospheric nitrogen; they believed that the 'madre de cacao' supplied water for the roots of the cacao, a fanciful idea still credited by many planters of cacao and coffee. In the Pacific we encounter a similar fact with reference to the yam bean (Pachyrhizus), a leguminous vine with a fleshy edible root. The natives of the Tonga Islands no longer cultivate Pachyrhizus for food, but they nevertheless encourage its growth in their fallow clearings in the belief that it renders them the sooner capable of yielding large crops of yams. Such anticipations of the results of modern agricultural science are of extreme interest, but it is still uncertain whether similar knowledge exists in other archipelagos of the Pacific, or on the American continent where Pachyrhizus probably originated. The botanists report it as 'a common weed in cultivated grounds,' and we learn further that in the absence of better material, the people of Fiji use the fiber for fish-lines, and that the plant sometimes figures in an unexplained manner in their religious ceremonies.
Our knowledge is far from complete regarding even the present distribution of the principal tropical food plants, but the need of further investigation should not obscure the striking fact that several of the food plants with which the Spaniards became acquainted in the West Indies were also staple crops on the islands and shores of the Pacific and Indian Oceans, and even across tropical Africa.
Ethnologists who might have appreciated the bearing of this have passed it by because of the absence of maize or Indian corn among the Polynesians. But in addition to the unreason of accepting negative evidence as an offset for positive fact, two pertinent considerations have been overlooked, first, that most of the varieties of maize do not thrive in the humid climates of the equatorial islands, and, second, that maize was found by Captain Moresby in cultivation with yams, sweet potatoes and sugar-cane in eastern New Guinea and the adjacent islands, among Polynesian tribes who had never been visited by Europeans and who were ignorant of salt, iron and rice. Tobacco was also known among many primitive peoples of the Orient before they came in contact with Europeans, though these and many similar facts have remained obscure because the European discoveries of the East and the West Indies were practically simultaneous. Moreover, nearly a century elapsed between the discovery of America and the realization that it was indeed a new world and not merely an eastward prolongation of Asia, so that the community of food plants did not at first appear remarkable.
The Agriculture of Ancient America.
|*Many species of true yams (Dioscorea) are cultivated, and the roots of numerous wild species are collected for food in various parts of the Tropics. The present reference is to D. alata, the most widely distributed of the domesticated species, and not known in the wild state.|
The most important food-plants of the Polynesians were seven in number, the taro, yam,* sweet potato, sugar-cane, banana, breadfruit and cocoanut, of which six, or all except the breadfruit, existed in pre-Spanish America, and of these, five, or all except the cocoanut, were propagated only from cuttings.
From the botanical standpoint the breadfruit is as distinctly Asiatic as the cocoanut is American, but although many seedless varieties of the breadfruit were distributed among the eastern archipelagos of Polynesia, these did not reach America until introduced by Captain Bligh in 1793, while the cocoanut must have crossed the Pacific thousands of years before, in order to give time for the development of the numerous and very distinct varieties cultivated in the Malay region. Except with the banana, botany gives much evidence for and none against the new world origin of the food plants shared by ancient America with Polynesia and the tropics of the old world, though few of them are known under conditions which warrant a belief that they now exist anywhere in a truly wild state. The partial or complete seedlessness attained by several of the important species also indicates dependence upon human assistance in propagation for a very long period of time, and precludes all rational doubt that their wide dissemination was accomplished through the direct agency of primitive man.
|†Frobenius, Zcitsch. der Oesellsch. fur Erdkunde zu Berlin, Bd. 33, 1898. Report of the Smithsonian Institution for 1898, pp. 637-650.|
Ethnologists will not deny that in the old world this distribution was the work of the ancestors of the Polynesians, who have been traced from Hawaii and Easter Island to Madagascar, and even across the African Continent,† We have not, however, been provided with any explanation of the existence of these food plants in America, for it is now generally agreed that the tribes, languages and arts of the American Indians are of truly indigenous development, while it is held, on the other hand, that the Polynesians migrated eastward from Asia, but without reaching the shores of America. That these two suppositions can not both be true is apparent as soon as it is known that there has been a transfer of numerous cultivated plants between Polynesia and America, and other agricultural facts enable us to judge between the inconsistent theories. Since it is reasonable to suppose that the food plants which the Polynesians shared with the tropical peoples of both continents were carried by them across the Pacific, it is also reasonable to seek the origin of these widely distributed species on the continent which gives evidence of the oldest and most extensive agricultural activity, and to the question in this form there can be but one answer. The agriculture of the old world tropics is adequately explainable by the supposition that it was brought by the Polynesians, since the root-crops of the Polynesians were also staples of the old world tropics. This proposition would not apply to America, where, in addition to the sweet potato, yams, yam-bean (Pachyrhizus) and taro, which crossed the Pacific, the aborigines also domesticated a long series of root-crops—Manihot (cassava), Maranta (arrowroot), Calathea (lleren), Solanum (Irish potato), Xanthosoma (several species), Oxalis (Oca), Canna, Tropaeolum, Ullucus, Arracacia, Sechium and Helianthus (artichoke), all of considerable local importance.
|*Sechium is perhaps an exception, but the more varied and localized names of the root are an indication that this plant was first domesticated as a root-crop. It may also be noted that Sechium is peculiarly adapted for teaching the art of planting seeds, since the fruit does not decay, but remains alive and edible long after the contained seed has germinated and sent forth a new vine with its leaves and roots. (See 'The Chayote: A Tropical Vegetable,' Bulletin No. 28, Div. of Botany, U. S. Dept. of Agriculture.)|
The simplest of cultural methods, propagation from cuttings, was applied to all these root-crops* and has been in use for so long a period that several of them have become seedless. With equal uniformity the distinctively old world root-crops are grown from seed. American root-crops belong to at least twelve natural families, and the only important old world addition to the series is the mustard family, a distinctly temperate group, the cultivated members of which have not been greatly modified in domestication, and are still known in the wild state.
This apparent superfluity of American root-crops is explainable by the fact that different plants were independently domesticated in different localities, which means also that conditions favorable to the development of agriculture were very general among the natives of America. That most of these plants are not known in the wild state testifies also to the great antiquity of this agricultural tendency, while archeology gives equally vivid testimony to the same antiquity and diversity of the prehistoric civilizations of America. From the mounds of Ohio to the equally remarkable ruins of Patagonia, the American continents and islands are, as it were, dotted with remains of rudimentary civilizations which must have required centuries and millenniums to rise from surrounding savagery, culminate and perish. The constructive arts by which the existence of these vanished peoples is made known took the most diverse forms; some made mounds, some expended their energies upon huge carvings on high inaccessible rocks, some dug devious underground passages, some set up monoliths and carved statues, and some built massive pyramids, temples and tombs, while still others are known only from their pottery or their metal work. In civilization, as in agriculture, the tropics of America stand in striking contrast to those of the old world. Here men of the same race showed great diversity of plants and arts; there races are diverse, while arts and staple food-plants are relatively little varied. The early civilizations of the eastern world resembled some of the primitive cultures of America more than these resembled each other.
The American origin of agriculture is thus not doubtful, since not merely one, but several, agricultures originated in America. The same cannot be claimed for Asia and Africa, where only root-crops shared with America attained a wide distribution, an indication that they reached those continents before the uses of the similar indigenous plants had been discovered.
The American habit of eating roots was not a simple and direct transition from the use of fruits, which are commonly supposed to have been the primitive food of man. The more important and the more ancient of the distinctively old world root-crops, onions, leeks, garlic, carrots, radishes and turnips, are eaten, or are at least edible, in the raw state, while in America there seems to be no indication that the natives used any of their root-crops in this way. Some of them, such as the sweet potato, the artichoke and the 'sweet cassava,' can be eaten raw, but throughout the tropics of America the Indians, like the Chinese, prefer everything cooked. This habit must have been adopted very far back to have made possible the obviously ancient domestication of Manihot (cassava), Colocasia (taro) and Xanthosoma (yautia), since the fleshy underground parts of these plants contain substances distinctly deleterious until disintegrated and rendered harmless by heat. The same may have been true of the sweet potato, since the fleshy roots of its uncultivated relatives are strongly purgative. Several of the yams, both wild and cultivated, are also poisonous in the raw state.
A culinary art which remained largely confined to the aborigines of tropical America and to the straight-haired races of the tropics of the old world is the making of starch or meal from roots which have been grated, soaked, washed or boiled with alkalies to destroy their poisonous properties. Separated from the sugars and other readily soluble substances which retain or absorb moisture, the starch of the taro, cassava, arrowroot, canna and other root-crops can be quickly and thoroughly dried, and will then keep indefinitely. In the absence of cereals this simple expedient might well be deemed an epoch-making discovery, since it rendered possible the accumulation of a permanent, readily transportable food supply, and thus protected man from the vicissitudes of the season and the chase. That the resulting economic difference appeared striking to the hunting tribes of Guiana is apparent in the name they gave to their agricultural neighbors, whom they called 'Arawacks’ or 'eaters of meal.'
|*Some of these tribes are extremely primitive and in the absence of all domestic implements grate their cassava on the exposed spiny roots of another native palm (Iriartea exorhiza). The Arawacks are similarly dependent upon still a third palm (Mauritia), from the pith of which they secure starch in a manner strongly suggestive of that used with the sago palm of the Malay region.|
Cassava in the raw state carries a deadly charge of prussic acid and begins to decay in a few hours after being taken from the ground, but properly prepared it furnishes the starch which keeps best, and which in the form of tapioca our civilization is tardily learning to appreciate as a wholesome delicacy. In view of its unpromising qualities when raw, cassava would seem not to have been the first root-crop from which meal was made, and yet it is used by many South American tribes* who plant nothing else except the so-called peach palm (Guilielma), which gives suggestive evidence of a cultivation much older than that of the date palm, since it is generally seedless, and it is not known in the wild state. The farinaceous fruits are made into meal and baked into cakes in the same manner as the cassava, to which resource is necessary during the months in which the single harvest of palm fruits is exhausted.
Cassava is, indeed, so distinctively the best, as well as the most generously and continuously productive of the tropical root-crops, that it could hardly have been known in the regions in which the others were domesticated. Ever since the Spanish conquest put an end to the isolation of the native peoples of tropical America the use of cassava has been slowly extending at the expense of similar crops; it has also found a footing in the Malay region and other parts of the East, though from present indications it may be thousands of years before its value will be properly appreciated. The slow extension of so desirable a plant among the tropical peoples excludes also the suggestion of any recent introduction from Polynesia of the taro or other root-crops which the Pacific peoples shared with the American.
|*Botanists have found that the native names of plants are more numerous and are used with more precision in Porto Rico than elsewhere in the West Indies. The common opinion that the aborigines of this island were exterminated by the Spaniards is evidently quite erroneous. In the mountainous interior district there are thousands of people who have no negro admixture and who are accordingly enumerated in the census as whites, but who are Spaniards only in language and in the wearing of cotton prints. Their agriculture, architecture and domestic economy show little foreign influence, and there is no reason for believing that these natives differ seriously from their pre-Columbian ancestors.|
Indeed, it is not unreasonable to believe that the taro, like the closely similar aroids of the genus Xanthosoma, was domesticated somewhere about the shores of the Caribbean Sea, where it has a large variety of native names in contrast to the single designation applied to it by the Polynesians. In Porto Rico, where the highest aboriginal culture of the West Indies was attained,* four aroids had the same generic name, yautia, which was adopted by the Spanish settlers. Strangely enough it is only with the taro, yautia malanga, that the native specific term has been preserved, three species of Xanthosoma having now only Spanish adjectives, yautia blanca, yautia amarilla and yautia palma. Botanists have never expressed a doubt that the species of Xanthosoma, some of which are known only in cultivation, originated in the West Indies and the adjacent parts of South America, and as these seem to be preferred to the taro, we must either look upon the latter as also indigenous in the West Indies or explain its presence by a movement from the mainland analogous to that which could have carried the same taro and numerous other American plants into the Pacific. Taro seems to have been the only cultivated aroid of the region of Panama whence some ethnologists have derived the sea-faring cannibals, the Caribs. To believe that the taro furnished the suggestion for the utilization of the Xanthosomas and also for that of Alocasia, Amorphophallus, Cyrtosperma and other aroids indigenous to the East Indies, seems far less irrational than to suppose that the strange habit of eating these painfully unpalatable plants originated independently in numerous primitive communities.
From Root-Crops to Cereals.
While it is, of course, not certain that the preparation of the starchy root-crops constituted the first regular application of fire to vegetable food, it is apparent that meal-eaters would be in a much better position than fruit-eaters or meat-eaters to attack the final problem of primitive agriculture, the use of cereals. Without the winter protection which primitive man could not supply, the culture of cassava and other tropical root-crops is confined to strictly tropical climates, so that increase of latitude and altitude would bring to starch-eating peoples the necessity of a change of food plants. Indeed, altitude seems to have played a larger part than latitude in this transformation which brought about the adoption by primitive American peoples of Indian corn, 'Irish' potato, arracacha, oca and other crops, of the temperate plateaus of South America. Without reasonable doubt, maize is the oldest of cereals, and the large soft kernels which distinguish it from all other food-grasses are exactly the character which would render it easily available to the meal-eating aborigines of America, though it is not to be supposed that the wild progenitor of the Indian corn had any very close similarity to our cultivated plant. Moreover, everywhere in tropical America maize is still prepared by methods adapted to root-crops instead of as a cereal. The rough stone slab (metate) against which they had rubbed their cassava or other starch-producing roots was well suited to making paste from maize, softened by soaking in water with lime or ashes, and throughout tropical America it has remained in use to the present day. Among the tribes of the arid temperate regions where the tropical root-crops were excluded the metate was deepened into the mortar in which seeds too small to be collected or handled singly are also bruised into meal.
It is also not impossible that maize was the first plant to be grown by man from seed, a cultural method permitting much easier and more rapid distribution than had been practicable with the root-crops grown from cuttings and tubers. Like other species cultivated in the highlands of tropical America most varieties of maize do not thrive in moist equatorial regions of low elevations, so that it did not seriously supplant the root-crops, though having a far wider distribution than any other plant cultivated by the aborigines in pre-Spanish America. Nor did the utilization of maize mark the limit of cereal cultures in America, though no other small foodseed of the new world compares in popularity with rice, wheat, barley, rye and oats. Even in Mexico, the supposed home of maize, the seeds of Amaranthus and Salvia (Chia) attained considerable economic importance. In addition to their use as food the latter were made to furnish a demulcent drink and an edible oil valued as an unguent and in applying pigments, a series of functions closely parallel to those of sesame, perhaps the most ancient of old world herbaceous seed-crops. Wild seeds of many kinds were collected by the Indians of the United States and Mexico, including wild rice (Zizania) and Uniola, another rice-like, aquatic grass of the shallow shore-water of the Gulf of California. In Chili there existed also several incipient cultures of small-seeded plants, such as Madia, while the people of the bleak plateaus of Peru and Bolivia had developed a unique cereal crop from a pigweed (Chenopodium quinoa), another of many evidences of a very general tendency to agricultural civilization in ancient America.
As long recognized by historians and ethnologists, maize was the most important factor in the material progress of ancient America, and the American civilizations remained on a much more strictly agricultural basis than those of the old world, a fact not without practical significance to modern agriculture since it undoubtedly conduced to the more careful selection and improvement of the many valuable plants which we owe to the ancient peoples of America. Subordinate only to maize from the agricultural standpoint was the domestication of the beans, while the materials for a developed culinary art and a varied and wholesome diet were furnished by a variety of minor products like the Cayenne pepper, the tomato, the tree tomato (Cyphomandra), the pineapple, several species of the strawberry tomato (Physalis), the pawpaw (Carica), the granadilla (Passiflora quadrangularis), the gourd, the squash and the peanut. American fruit trees, such as the custard apple and related species of Anona, the alligator pear (Persea), the sapodilla, Mammeas and Lucumas afford refreshing acids, beverages, relishes or salads, but do not furnish substantial food like the banana. Contrary to the opinion of De Candolle there is every probability that the banana reached America from the west long before the arrival of the Spaniards, but it evidently did not come until after the agriculture and cultivated plants of America had spread into the Pacific.
No Pastoral Period.
The agricultural history of the Malays, Chinese, Japanese, and other Mongoloid peoples of the western shores of the Pacific, is exactly that of the American races, and differs fundamentally from that of the peoples of western Asia and the Mediterranean region in giving no indications of a primitive pastoral stage which so many writers have taken to be man's first step from savagery toward civilization. The straight-haired peoples made, however, early and vigorous use of a large number of Asiatic plants and showed skill in agriculture and irrigation equaled in prehistoric times only along the western coasts of America, among the congeries of primitive civilizations commonly not distinguished from the terminal members of the series, the Peruvians and Mexicans.
That the Aztec and Inca empires were comparatively recent organizations has caused many ethnological writers to forget that they incorporated much more ancient culture. For centuries still unnumbered the Andean region of South America supported crowded populations. On the western slopes of Peru every inch of irrigable land was cultivated, houses and towns being relegated to waste places. The temperate food plants of Peru and China are all apparently indigenous to their respective continents. They testify to the independent development of the temperate agricultures of the two regions, but it seems certain that both were the successors of more tropical starch-eating populations, parts of which had been crowded back to the relatively inhospitable plateaus of Peru and Bolivia, and to the bleak plains of northern China, where the primitive tropical root-crops were, of necessity, replaced by more hardy indigenous species. The Chibcha people of the interior of Colombia attained a considerable degree of advancement without adopting a single domestic animal. The Peruvians and Chinese learned to use beasts of burden and animal fibers and skins, but their pastoral efforts were merely incidental to agriculture; they remained essentially vegetarians, eating little meat, and never taking up the use of milk.
The Domestication of the Banana.
In further support of the suggestion that the use of the starch-producing root-crops is a distinctively American development of primitive agriculture is the fact that the tropics of the old world contributed no important cultivated plant of this class, and none which gives evidence of long domestication. On the other hand, such regions as Madagascar and East Africa, where Polynesians are now supposed by ethnologists to have settled in ' remote prehistoric times,' continued the culture and differentiation of the varieties of the taro and the sweet potato, and were agriculturally mere outposts of the American tropics.
|*The suggestion that the primitive culture race which domesticated the banana came from America also receives definite support from the fact that an American plant (Heliconia bihai), somewhat similar to the banana but without an edible fruit, reached the islands of the Pacific in prehistoric times. Though no longer cultivated by the Polynesians, it has become established in the mountains of Samoa and in many of the more western archipelagos. In New Caledonia the tough leaves are still woven into hats, but the Pandanus, native in the Malay region, affords a better material for general purposes and has displaced Heliconia in cultivation among the Polynesians. In the time of Oviedo the natives of the West Indies made hats, mats, baskets and thatch from the leaves of Heliconia, and the starchy rootstocks were eaten.|
The presence of the banana might be thought to explain the relatively small importance of root-crops in the old world, since it furnishes with far less effort of cultivation and preparation a highly nutritious and palatable food. It appears, however, that the use of root-crops must have preceded the domestication of the banana, for although the seed-bearing wild bananas are utterly worthless as fruits and hence would not have been domesticated as such, nevertheless more species of them than of any other genus of food plants were brought into cultivation. The clue to this paradox is afforded by the fact that bananas are still cultivated as root crops in the old world tropics, particularly in New Caledonia and Abyssinia.*
That the varieties used for this purpose are as old or older than those grown for fruit is indicated by the fact that, like the sweet potato, taro and sugar-cane, they seldom produce flowers. Furthermore, among all savage tribes the varieties valued by civilized peoples as fruits are relatively little used, far greater popularity being enjoyed by the so-called 'plantains,' not edible in the raw state, even when ripe, though nearly always cooked and eaten while still immature, or before the starch has changed to sugar. They are also in many countries dried and made into a meal or flour often compared to arrowroot.
In dietary and culinary senses the breadfruit also is as much a vegetable as the taro or the sweet potato; as a fruit it would be no more likely to be domesticated than its distant relative the Osage orange. The farinaceous character of the breadfruit also probably explains its relatively greater importance among the Polynesians than in its original Malayan home, as shown by the propagation of numerous seedless varieties. The popularity of the breadfruit among the Polynesians was further extended by the discovery that the fruits could be stored in covered pits, the prototypes of the modern silo.
If the domestication of the banana is to be ascribed to cultivators of root-crops, the same reasoning applies with even greater propriety to cereals. Tribes accustomed to subsist upon mangoes, dates, figs or similar fruits which require no grating, grinding or cooking, and are eaten alone and not with meat, would not develop the food habits and culinary arts necessary to equip primitive man for utilizing the cereals.
Wild bananas and their botanical relatives are natives of the rocky slopes of mountainous regions of the moist tropics where shrubs and trees prevent the growth of ordinary herbaceous vegetation. The commencement of the culture of cereals by fruit-eating natives of such forest-covered regions is obviously improbable, but such an undertaking would be a comparatively easy transition for the meal-eating cultivators of root-crops, since the grasses and other plants domesticated for their seeds are exactly those which flourish in cleared ground and are prompt to take advantage of the cultural efforts intended for other crops. Thus, the Japanese have by selection secured a useful cereal from the common barnyard-grass (Panicum crus-galli) just as they have made a root-crop of the burdock. Accordingly, we should look to some taro-growing tribe of southeastern Asia as the probable domesticators of rice, and to other cultivators of root-crops for similar services in taking up the somewhat less tropical cereals, sesame and Guinea corn. That root-crops preceded cereals in America was inferred above partly from the fact that root-crops were not there grown from seeds; and there is a corresponding indication that the knowledge of cereals preceded the domestication of the seed-grown temperate root-crops of the old world, since none of these is anywhere dried, made into starch, or otherwise prepared for storage as the basis of a permanent food-supply of primitive tribes.
That the fruit-eating aborigines of the old world were not equipped for undertaking the use of cereals is further shown by the fact that those who left the moist tropics for the subtropical and temperate regions of Western Asia, North Africa and Europe did not resort, as in America, to the culture of more hardy root crops and cereals, but became pastoral nomads, dependent upon the milk and flesh of their herds, supplemented by such honey, wild fruits and other edible plants as they might encounter in searching for pasture. Dates, figs and other fruit trees might receive some attention from such wanderers, but the more successful they might become as shepherds the less likely they would be to take up the planting of cereals or of other herbaceous crops, which in the absence of fences would be appropriated by their animals before the owners could make even an initial experiment. It is accordingly significant that the origin of the agricultures and civilizations of the valleys of the Nile and Euphrates is no longer sought by ethnologists with Semitic shepherds or more northern peoples, but with a seafaring race which has been traced to southern Arabia, and whose language has been found to have analogies with the ancient Polynesian tongue of Madagascar.
With the exception of the banana, the cultivated plants which were shared with America by the natives of the islands of the Pacific and of the old world tropics appear to be of American origin, and the wide distribution of these plants in the east and the relatively recent domestication of the old world root crops and cereals accord with the suggestion that the agricultural skill and compact social organization of a primitive American culture race were transferred to southern Asia during the movements of conquest and colonization which spread the Malayo-Polynesian linguistic stock from Hawaii and Easter Island to Madagascar and southern Arabia, but long anterior to existing peoples or languages. The cocoanut which affords so direct an intimation of American origin has already explained the failure of those who have attempted to demonstrate identity of languages, customs and arts on the two sides of the Pacific, but also condemns the equally erroneous attitude of others who refuse, in the absence of such identity, to accept the countless trans-Pacific similarities as indications of affinity or common origin.
The distribution and uses of the tropical cultivated plants support the belief of ethnologists in the truly indigenous character of the peoples, agricultures and civilizations of the new world, but they also testify to a very early colonization of the islands of the Pacific and Indian oceans from tropical America. The comparative deficiency of the western continent in fruits and animals suitable for food was compensated by numerous starchy root-crops. The primitive culture peoples of the tropical regions of ancient America were accustomed to the cooking, grinding, and storing of vegetable food, and were thus prepared to appreciate and utilize the cereals by agricultural experience lacking among the fruit-eating aborigines of the old world, who developed instead the arts of the chase, the domestication of animals, and the use of milk. But fruit, meat and milk do not complete the agricultural series, and do not include its essential members, since civilizations have nowhere developed without the assistance of the farinaceous root-crops and cereals, the use and cultivation of which are habits acquired by primitive man in America and carried in remote times westward across the Pacific, together with the social organization and constructive arts which appear only in settled communities supported by the tillage of the soil.
By means of agricultural facts it is possible thus to choose between the rival theories of the ethnologists, and in addition to gain a suggestion of the history of agriculture among primitive peoples. If we may not know where man first began to encourage the growth of the plants which furnished his food, we are not without numerous indications that agriculture proper, together with the agricultural organization of human society which lay behind modern civilization, originated in America and has now completed the circuit of the globe.