Auguste de Saint-Hilaire[1994] thought he recognized the wild type in a singular variety, of which each grain is enclosed within its sheath or bract. It is known at Buenos-Ayres under the name pinsigallo. It is Zea Mays tunicata of Saint-Hilaire, of which Bonafous gives an illustration, pl. 5, bis, under the name Zea cryptosperma. Lindley[1995] also gives a description and a drawing from seeds brought, it is said, from the Rocky Mountains, but this is not confirmed by recent Californian floras. A young Guarany, born in Paraguay on its frontiers, had recognized this maize, and told Saint-Hilaire that it grew in the damp forests of his country. This is very insufficient proof that it is indigenous. No traveller to my knowledge has seen this plant wild in Paraguay or Brazil. But it is an interesting fact that it has been cultivated in Europe, and that it often passes into the ordinary state of maize. Lindley observed it when it had been only two or three years in cultivation, and Professor Radic obtained from one sowing 225 ears of the form tunicata, and 105 of the common form with naked grains.[1996] Evidently this form, which might be believed a true species, but whose country is, however, doubtful, is hardly even a race. It is one of the innumerable varieties, more or less hereditary, of which botanists who are considered authorities make only a single species, because of their want of stability and the transitions which they frequently present.
On the condition of Zea Mays, and its habitation in America before it was cultivated, we have nothing but conjectural knowledge. I will state what I take to be the sum of this, because it leads to certain probable indications.
I remark first that maize is a plant singularly unprovided with means of dispersion and protection. The grains are hard to detach from the ear, which is itself enveloped. They have no tuft or wing to catch the wind, and when the ear is not gathered by man the grains fall still fixed in the receptacle, and then rodents and other animals must destroy them in quantities, and all the more that they are not sufficiently hard to pass intact through the digestive organs. Probably so unprotected a species was becoming more and more rare in some limited region, and was on the point of becoming extinct, when a wandering tribe of savages, having perceived its nutritious qualities, saved it from destruction by cultivating it. I am the more disposed to believe that its natural area was small that the species is unique; that is to say, that it constitutes what is called a single-typed genus. The genera which contain few species, and especially the monotypes, have as a rule more restricted areas than others. Palæontology will perhaps one day show whether there ever existed in America several species of Zea, or similar Graminæ, of which maize is the last survivor. Now, the genus Zea is not only a monotype, but stands almost alone in its family. A single genus, Euchlæna of Schrader, may be compared with it, of which there is one species in Mexico and another in Guatemala; but it is a quite distinct genus, and there are no intermediate forms between it and Zea.
Wittmack has made some curious researches in order to discover which variety of maize probably represents the form belonging to the epoch anterior to cultivation. For this purpose he has compared ears and grains taken from the mounds of North America with those from Peru. If these monuments offered only one form of maize, the result would be important, but several different varieties have been found in the mounds and in Peru. This is not very surprising; these monuments are not very ancient. The cemetery of Ancon in Peru, whence Wittmack obtained his best specimens, is nearly contemporary with the discovery of America.[1997] Now, at that epoch the number of varieties was already considerable, which proves a much more ancient cultivation.
Experiments in sowing varieties of maize in uncultivated ground several years in succession would perhaps show a reversion to some common form which might then be considered as the original stock, but nothing of this kind has been attempted. The varieties have only been observed to lack stability in spite of their great diversity.
As to the habitation of the unknown primitive form, the following considerations may enable us to guess it. Settled populations can only have been formed where nutritious species existed naturally in soil easy of cultivation. The potato, the sweet potato, and maize doubtless fulfilled these conditions in America, and as the great populations of this part of the world existed first in the high grounds of Chili and Mexico, it is there probably that wild maize existed. We must not look for it in the low-lying regions such as Paraguay and the banks of the Amazon, or the hot districts of Guiana, Panama, and Mexico, since their inhabitants were formerly less numerous. Besides, forests are unfavourable to annuals, and maize does not thrive in the warm damp climates where manioc is grown.[1998] On the other hand, its transmission from one tribe to another is easier to comprehend if we suppose the point of departure in the centre, than if we place it at one of the limits of the area over which the species was cultivated at the time of the Incas and the Toltecs, or rather of the Mayas, Nahuas, and Chibehas, who preceded these. The migrations of peoples have not always followed a fixed course from north to south, or from south to north. They have taken different directions according to the epoch and the country.[1999] The ancient Peruvians scarcely knew the Mexicans, and vice versâ, as the total difference of their beliefs and customs shows. As they both early cultivated maize, we must suppose an intermediate point of departure. New Granada seems to me to fulfil these conditions. The nation called Chibcha which occupied the table-land of Bogota at the time of the Spanish conquest, and considered itself aboriginal, was an agricultural people. It enjoyed a certain degree of civilization, as the monuments recently investigated show. Perhaps this tribe first possessed and cultivated maize. It marched with Peru, then but little civilized, on the one hand, and with the Mayas on the other, who occupied Central America and Yucatan. These were often at war with the Nahuas, predecessors of the Toltecs and the Aztecs in Mexico. There is a tradition that Nahualt, chief of the Nahuas, taught the cultivation of maize.[2000]
I dare not hope that maize will be found wild, although its habitation before it was cultivated was probably so small that botanists have perhaps not yet come across it. The species is so distinct from all others, and so striking, that natives or unscientific colonists would have noticed and spoken of it. The certainty as to its origin will probably come rather from archæological discoveries. If a great number of monuments in all parts of America are studied, if the hieroglyphical inscriptions of some of these are deciphered, and if dates of migrations and economical events are discovered, our hypothesis will be justified, modified, or rejected.
Article II.—Seeds used for Different Purposes.
Poppy—Papaver somniferum, Linnæus.
The poppy is usually cultivated for the oil contained in the seed, and sometimes, especially in Asia, for the sap, extracted by making incisions in the capsules, and from which opium is obtained.