88.  Triticum aestivum.  Spring wheat.—­Wheat is a grain well known in most countries in Europe.  It has been in cultivation for many ages.  This species was introduced some years ago from the Barbary coast, and has been found very beneficial for sowing in the spring, when it often produces a large crop.  It takes a shorter time to come to maturity than the other sorts; and as it is a more profitable crop to the farmer on good soils than Barley, it is frequently sown after Turnips are over.  This has, perhaps, been one of the best improvements in Grain husbandry that was ever introduced, as it gives the grower great advantages which he could not have under the common culture of Wheat at the usual seed-time.  This is little different in appearance from the Common White Wheat.  But there was a small variety of it with rounder grains sent to the Board of Agriculture from the Cape of Good Hope about the year 1801, of which I saved a small quantity of seeds which was distributed among the members; and I have lately seen a sample of it in the hands of a gentleman in Devonshire, who speaks very highly of it as producing a large crop in a short time, and that the flower was so much esteemed, that the millers gave him a higher price for it than the finest samples at market of the other kinds would sell for.  I believe this variety is very scarce.  It is now twelve years since I grew it, from which what I saw, and all other in cultivation, if any there are, have sprung.

89.  Triticum compositum.  Egyptian wheat.—­This is a species with branched ears, and commonly having as many as three and four divisions.  It is much cultivated in the eastern countries, but has not been found to answer so well in this country as the common cultivated species.

90.  Triticum hybernum.  Common wheat.—­Of this grain we have a number of varieties, which are grown according to the fashion of countries, differing in the colour of the ear and also of the grain.  The most esteemed sorts are the Hertfordshire White and the Essex Red Wheat, which are both much cultivated and equally esteemed.  The season for growing these kinds is usually September and October.  The drill, dibble, and broad-cast modes are all used, as the land and convenience of the farmer happen to suit, and the produce varies accordingly; as does also the quantity of seed sown.  From two pecks to two bushels and a half are sown on an acre.

Wheat is liable to the ravages of many terrestrious insects which attack its roots; and also some very curious diseases.  One of these has been very clearly elucidated by our munificent patron of science, Sir Joseph Banks, in the investigation of a parasitical plant which destroys the blood of the stalk and leaves, renders the grain thin, and in some cases quite destroys the crop, which has done that gentleman’s penetration great credit [Footnote:  Sir Joseph Banks On the Blight in Corn.].  An equally extraordinary disease