+Wheat and Kindred Species.+—The innumerable varieties of wheat, properly so called, of which the ripened grain detaches itself naturally from the husk, have been classed into four groups by Vilmorin,[1775] which form distinct species, or modifications of the common wheat according to different authors. I am obliged to distinguish them in order to study their history, but this, as will be seen, supports the opinion of a single species.[1776] +1. Common Wheat+—_Triticum vulgare_, Villars; _Triticum hybernum_ and _T. æstivum_, Linnæus. According to the experiments of the Abbé Rozier, and later of Tessier, the distinction between autumn and spring wheats has no importance. “All wheats,” says the latter,[1777] “are either spring or autumn sown, according to the country. They all pass with time from the one state to the other, as I have ascertained. They only need to be gradually accustomed to the change, by sowing the autumn wheat a little later, spring wheat a little earlier, year by year.” The fact is that among the immense number of varieties there are some which feel the cold of the winter more than others, and it has become the custom to sow them in the spring.[1778] We need take no note of this distinction in studying the question of origin, especially as the greater number of the varieties thus obtained date from a remote period. The cultivation of wheat is prehistoric in the old world. Very ancient Egyptian monuments, older than the invasion of the shepherds, and the Hebrew Scriptures show this cultivation already established, and when the Egyptians or Greeks speak of its origin, they attribute it to mythical personages, Isis, Ceres, Triptolemus.[1779] The earliest lake-dwellings of Western Switzerland cultivated a small-grained wheat, which Heer[1780] has carefully described and figured under the name _Triticum vulgare antiquorum_. From various facts, taken collectively, we gather that the first lake-dwellers of Robenhausen were at least contemporary with the Trojan war, and perhaps earlier. The cultivation of their wheat persisted in Switzerland until the Roman conquest, as we see from specimens found at Buchs. Regazzoni also found it in the rubbish-heaps of the lake-dwellers of Varese, and Sordelli in those of Lagozza in Lombardy.[1781] Unger found the same form in a brick of the pyramid of Dashur, Egypt, to which he assigns a date, 3359 B.C. (Unger, _Bot. Streifzüge_, vii.; _Ein Ziegel_, etc., p. 9), Another variety (_Triticum vulgare compactum muticum_, Heer) was less common in Switzerland in the earliest stone age, but it has been more often found among the less ancient lake-dwellers of Western Switzerland and of Italy.[1782] A third intermediate variety has been discovered at Aggtelek in Hungary, cultivated in the stone age.[1783] None of these is identical with the wheat now cultivated, as more profitable varieties have taken their place.