Invention of Agriculture.
Before examining in greater detail the art of the Archaic Horizon let us consider its real significance. It is generally admitted that America was originally populated from Asia, but on a culture level no higher than the Neolithic. The simple arts of stone chipping, basketry, fire-making, etc., were probably brought over by the earliest immigrants, but there is abundant evidence that pottery-making, weaving, and agriculture were independently invented long after the original settlement. The cultivated plants in the New World are different from those of the Old World and there is a vast area in northwestern America and northeastern Asia, upon the only open line of communication, where agriculture and the higher arts have never been practised.
Fig. 12. Teocentli or Mexican Fodder Grass.
Now the invention of agriculture is an antecedent necessity for all the high cultures of the New World. It is equally clear that this invention must have taken place in a locality where some important food plant grew in a wild state. By far the most important food plant of the New World is maize. While this plant has changed greatly under domestication, botanists are inclined to find its nearest relative and possible progenitor in a wild grass growing on the highlands of Mexico and known by the Aztecan name teocentli, which means sacred maize. It is known that maize is at its best in a semi-arid tropical environment. It cannot be brought to withstand frost although the growing season can be cut down to meet the requirements of a short summer. Geographically its use extended from the St. Lawrence to the Rio de la Plata and from sea level to an elevation of fifteen thousand feet in tropical regions. The Mexican highlands occupy the central position in the area of its distribution and archæological evidence strongly points to this region as being the cradle of agriculture and the attendant arts. Besides maize, the most widely distributed food plants of the New World are beans and squashes. Certain other plants were cultivated in more restricted areas and may have had different places of origin. For instance, manioc was doubtless brought under cultivation in a humid lowland region, probably the Amazon Valley, and the same may be said of sweet potatoes. The common potato was found under domestication in Peru and there is no very good evidence that its use extended into Central America.
Irrigation would have been necessary before agriculture could have been developed to any great extent on the highlands of Mexico. Although irrigation is often looked upon as a remarkable sequel of the introduction of agriculture into an arid country, yet from the best historical evidence at our command we should rather regard it as a conception which accounts for the very origin of agriculture itself. The earliest records of cultivated plants are from Mesopotamia, Egypt, Mexico, and Peru where irrigation was practised. In these regions are also 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.
If this theory is true we must admit that below the Archaic Horizon we should find traces of a horizon of non-agricultural peoples, living a nomadic life without pottery. Unfortunately, such peoples make fewer objects and scatter them more widely than do sedentary agriculturists.
No one on the basis of present knowledge can offer more than an opinion concerning the date of the invention of agriculture in the New World. The thick deposits left by the sedentary peoples argue great age and the wide area of homogeneous products argues slow change. In the most favored regions archaic art may have been succeeded by higher forms shortly before the time of Christ, and perhaps 5000 years is not too long a time to allow for the diversities of the domesticated plants of America.