24.

THE ORIGIN AND DISTRIBUTION OF AGRICULTURE IN AMERICA¹

ByH.J.SPINDENn/an/an/an/a

Agriculture may be named as the antecedent condition for all the high cultures of the New World. The concept of agriculture may have had several points of origin, but this does not seem likely, since maize, beans, and squashes were common products wherever agriculture was practised in America. Other plants, fitted for special environments, had a more limited distribution, examples being manioc (Manihot utilissima, etc.) of the humid lowlands of the Amazon basin and of the West Indies, and the potato (Solanum tuberosum) that was cultivated most extensively in the rather arid highlands of Peru. Wild stocks for some of the aboriginal food plants of America are often difficult to obtain, but botanical knowledge is far from complete for some of the most significant areas. We have proof of the migration of the agricultural complex from Mexico into the United States. In both the Mound Area and the Pueblo Area, the comparatively high state of society and art was directly dependent on agriculture, yet in these areas not one food product is known to have been locally developed from an indigenous plant. While the concept and the complex of agriculture undoubtedly migrated from Mexico into the southern and eastern parts of the United States we must be careful not to confuse this phenomenon with an actual migration of peoples. There is no reason to doubt that the plant culture spread as rapidly and as easily across tribal barriers in ancient times as horse culture in modern times.

There are arts that seem in a general way to be dependent on agriculture or at least concomitant with it. The most important of these is pottery. Pottery is of little use to people who are not stationary, and stationary people are usually (but not necessarily) agriculturists. In the New World we find that the boundaries of pottery distribution closely parallel the boundaries of agriculture distribution, extending in some regions slightly beyond them. Now pottery, with its infinite variation in form and ornament, furnishes us evidence of cultural connections and cultural developments that can be considered profitably along with problems of ancient American food plants.

If we could be certain that the early Mexican culture, now called the Archaic, was the direct outgrowth of the invention of agriculture and the subsequent stabilization of society, our position in regard to certain fundamentals of ancient American history would be very strong indeed. This Archaic Culture, studied best in its ceramic remains, seems to have had its birth on the highlands of Mexico and to have spread without much change as far as the Isthmus of Panama. Maize (Zea mays) seems to have been developed from a wild grass which may be the teosintli (Euchlaena mexicana) of the Mexican highlands. When we consider the geographical and climatic range of the adaptation of maize we must admit that the Mexican plateau is an intermediate and very likely home for the wild progenitor of this great food plant. On the north its cultivation had been extended in pre-Columbian times to the mouth of the St. Lawrence and on the south to the mouth of the Rio de la Plata. The plant had been accultured to extreme conditions of heat and cold, drought and moisture. To be sure there is in artificial cultivation, even when practised by primitive people, an obvious selective character that might rapidly lead to a differentiation of plant types. The saving of seed stock after any harsh condition has operated to cut down the yield naturally breeds immunity to that condition. Still it is much more reasonable to suppose that modification would take place from a mean toward each extreme of adaptation rather than from one extreme to the other.

It is certain that the early ceramic art of the Archaic Period was made by a people who practised agriculture. And it is becoming more and more clear that the migration of this ceramic art can be traced well into South America, although changes take place once we pass beyond the frontier of tribes speaking the Nahua language. The writer has presented evidence elsewhere that the widely scattered tribes speaking the Nahua language were probably culture-carriers of the archaic art. All these tribes have cognate words for agricultural products, which fact shows that the separation took place after agriculture had been developed.

Theoretically, agriculture would be more likely to originate under conditions that were hard rather than under those that were easy. Necessity, they say, is the mother of invention. An environment producing a healthy but hungry population, particularly a semi-arid environment, would offer special inducements to the first agriculturists. They would have no heavy work in preparing the soil, and irrigation would make them masters of nature.

Irrigation is often looked on as a remarkable sequel of the introduction of agriculture into an arid country. But from the best historical evidence at our command we should rather regard it as an invention which accounts for the very origin of agriculture itself. The earliest records of cultivated plants are seen in Mesopotamia, Egypt, Mexico, and Peru, where irrigation was practised, and in each region are likewise seen the earliest developments of the characteristic arts of sedentary peoples, namely, pottery and weaving, and the elaborate social and religious structures that result from a sure food supply and a reasonable amount of leisure.

Quite aside from these known facts in the case, there are several reasons why. we should look for the first appearance of agriculture in an arid environment. The press of population on food supply is greater there than in free-and-easy lands where nature is bountiful but where an insidious competition works behind the screen of plenty and cuts down life. In the desert the clearing of the field is less laborious than in the jungle and the control of the life-giving water makes man the master of the entire situation. As for the intermediate type of environment, where agriculture is possible without irrigation and where it normally spreads with the rise of human culture, there is usually such a supply of wild game, of berries, of edible roots, etc., that the advantage of tilling the soil does not at first appear. Even when agriculture is known in such favorable country, the indigenous plants are seldom found in cultivation. The abundant harvests of wild acorns in California, of wokas in southern Oregon, of wappato along the Columbia, of camas and kous in the pleasant uplands of Idaho, and of wild rice in the lake region of Minnesota and southern Canada, were effectual barriers against the invention or spread of agriculture among the tribes inhabiting these regions. . . .

Map 1 shows the final distribution of pottery in the New World. Aside from the independent development of crude ceramic art among the Alaskan Eskimo, the whole grand area may show the result of a spreading-out of the pottery concept from a single point of origin. Everywhere in this great stretch of territory the use of pottery is practically limited to agricultural peoples. The area is, to be sure, somewhat larger than that held by the agricultural tribes of today. The oversize can be explained on two grounds. In some regions the pottery remains are scanty and sporadic and may be ascribed to nomadic Indians who made a slight use of the pottery objects manufactured by their sedentary neighbors. In other outside regions the pottery remains are so plentiful as to indicate that agriculture was once practised there but has now been given up. For instance, there was never more than a slight use of pottery in the western stretches of Kansas, Oklahoma, and Texas, where the nomadic Kiowa and Comanche dwelt, at least in later times; while in southern Colorado and southeastern Utah, a rather high type of agriculture was once established but has long since given way to a ruder manner of life.

In South America the southern limits of pottery have never been carefully worked out. Potsherds at old Tehuelche camp sites are reported

Map 1. Pottery in the New World. Intensive regions in black; nonpottery regions in white.

from considerably farther south than agriculture appears to have spread. The two non-pottery areas marked on the map in the central part of the continent are somewhat uncertain. Throughout the area drained by the Amazon and Plata systems pottery-making and agriculture follow the larger streams, whose banks are held by the better tribes. But in the higher land back from these streams much more primitive tribes are found, such as the Ges of the Brazilian highlands and the Nambiquara of the Matto Grosso. The latter practise a little agriculture at the present time, but hardly deserve the name of agriculturists.

Map 2 gives the limits of the distribution of agriculture in the New World and makes a rough distinction between three general types of agriculture. The first and apparently oldest type occurs in open and rather arid territory of considerable elevation, where irrigation is usually necessary. The second type is found in the humid, tropical lowlands where the land must ordinarily be cleared of the forest before planting can be done. The third type occurs under temperate conditions in partly open and partly forested country where irrigation is not required.

The arid highland area extends from southern Colorado and Utah down the cordillera and over the plateaux of Mexico, Colombia, Peru, and Bolivia, to southern Chile. An outlying area is also drawn across the Guiana highlands, but this is somewhat doubtful and proof of its existence must await future exploration. Much of northern South America, back from the coast, is savanna and sparsely timbered plain.

Agriculture seems to have received special emphasis in Mexico and Peru. Maize, beans (Phaseolus vulgaris), squashes (Cucurbita maxima and C. pepo) are common to both areas, but with considerable local variation. Sweet potatoes (Ipomœa batatas, the camotl of the Aztecs) are also cultivated in both Mexico and Peru, but are probably of humid lowland origin. In Mexico several varieties of Capsicum annuum (known to us by the Aztec word chile) were cultivated, as well as the tomato (Lycopersi-cure esculentum), called tomatl in Aztec. The latter was used mostly in softening the rigors of chile sauce, and several varieties are described in early books. Cacao (Theobroma cacao) takes its mispronounced name from the Aztec word cacauatl, which referred to the dried nibs. When ground this fruit seed was called chocolatl and was made into a delicious drink. Cacao was grown under the shade of another tree, called the "mother of cacao," in the lower and more humid parts of Mexico and Central America, and was an object of trade with the highland tribes. This plant does not seem to have been known to Peru, although the mountain tribes of western Venezuela cultivated it and made a drink called chorate from the seeds. Cacao was grown also in many parts of the lowlands of South America and in the West Indies. It is likely that more than one species has been brought under cultivation.

Map 2. Agriculture in the New World. Mountainous and mostly arid regions in black; lowland humid regions stippled; temperate region in lines.

In Peru, the potato (Solanum tuberosum) was especially developed. It is doubtful if this plant was known to the Mexicans, although it was commonly grown throughout the Andean region and a wild form occurs as far north as Colorado. Peanuts (Arachis hypogaea) also appear to be a Peruvian specialty. There was a sort of fruit called by the Aztecs tlalcacauatl. ("earth cacao"), which is said to have been roasted before eating. This fruit may possibly be identified with the peanut, since the modern Mexico word for peanut is cacahuate. In South America the Peruvian word mani is used. Several wild species of peanuts are said to occur in South America. Other Peruvian and Colombian products are the roots of oca (Ocalis crenata and O. tuberosa) and of arracacha (Arracacia xanthorrhiza). Great use was also made in Peru of the seeds of quinoa (Chenopodium quinoa). In Mexico dry seeds of similar type appear to have been used in quantity.

The second type of agriculture is that developed to meet the conditions of the humid and heavily forested tropics. The Maya culture, probably the most brilliant of the New World, was made possible by the agricultural conquest of the rich lowlands of Central America. On the highlands the preparation of the soil is comparatively easy owing to scanty vegetation and a control vested in irrigation. On the lowlands, however, great trees have to be felled and fast-growing bushes kept down by untiring energy. But when nature is truly tamed she returns recompense many fold to the daring farmers. Moreover, there is reason to believe that the removal of the forest cover over large areas affects favorably the conditions of human life which under a canopy of leaves are hard indeed. . . .

But while extremely high civilization might result when the natural wealth of the humid tropics was garnered by a closely organized people, the general run of more or less haphazard agriculture in the tropics leads to no such state of affairs. In the great Amazon valley and in the flanking valleys of the Orinoco and the Plata, we find agriculture unaccompanied by high social developments, although weaving and pottery-making are everywhere practised. Maize, beans, and squashes are known throughout this area, but maize is displaced from the position of first importance by manioc. Two species of this plant are used, one (Manihot utilissima) having a poisonous juice and the other (M. aipi) being harmless. Both plants, along with many other species of the same family, are said to grow wild in Brazil, and there is little doubt that domestication first took place in this area. A single technical process of extracting the poisonous juice of the favorite manioc is found wherever the plant is cultivated, and similar types of clay griddles are used in making the cassava cakes. . . .

While the general classification of tropical agriculture into arid highland and humid lowland types is hardly to be disputed, still there are many domesticated plants that cannot be definitely ascribed to the one environment as opposed to the other. It seems likely that maize, beans, squashes, potatoes, tomatoes, malanga (Xanthosoma sagittifolium), etc., were originally of humid land origin. . . .

The third type of agriculture was adapted to temperate conditions. It is most completely exemplified in the eastern half of the United States, but seems also to have been developed, though to a much less extent, in parts of the Argentine and Uruguayan pampas. Maize is again the staple, with beans and squashes as associated crops. Among the Mandan of North Dakota maize was modified to meet the conditions of a very short summer and ripen within sixty or seventy days of planting. Among the Iroquois agriculture was also brought to a high plane, especially when we consider that all the plants under cultivation were indigenous to the tropics

¹