The foremost feature of disease in wheat is the oat.308 Barley, too, will degenerate into the oat; so much so, in fact, that the oat has become an equivalent for corn; for the people of Germany are in the habit of sowing it, and make their porridge of nothing else. This degeneracy is owing more particularly to humidity of soil and climate; and a second cause is a weakness in the seed, the result of its being retained too long in the ground before it makes its appearance above it. The same, too, will be the consequence, if the seed is decayed when put in the ground. This may be known, however, the moment it makes its appearance, from which it is quite evident that the defect lies in the root. There is another form of disease, too, which closely resembles the oat, and which supervenes when the grain, already developed to its full size, but not ripe, is struck by a noxious blast, before it has acquired its proper body and strength; in this case, the seed pines away in the ear, by a kind of abortion, as it were, and totally disappears.

The wind is injurious to wheat and barley, at three309 periods of the year in particular: when they are in blossom, directly the blossom has passed off, and just as the seed is beginning to ripen. In this last case, the grain wastes away, while in the two former ones it is prevented from being developed. Gleams of sunshine, every now and then, from the midst of clouds, are injurious to corn. Maggots, too, breed310 in the roots, when the rains that follow the seed-time are succeeded by a sudden heat, which encloses the humidity in the ground. Maggots make their appearance,311 also, in the grain, when the ear ferments through heat succeeding a fall of rain. There is a small beetle, too, known by the name of “cantharis,”312 which eats away the blade. All these insects die, however, as soon as their nutriment fails them. Oil,313 pitch, and grease are prejudicial to grain, and care should be taken not to let them come in contact with the seed that is sown. Rain is only beneficial to grain while in the blade; it is injurious to wheat and barley while they are in blossom, but is not detrimental to the leguminous plants, with the exception of the chick-pea. When grain is beginning to ripen, rain is injurious, and to barley in particular. There is a white grass314 that grows in the fields, very similar to panic in appearance, but fatal to cattle. As to darnel,315 the tribulus,316 the thistle,317 and the burdock,318 I can consider them, no more than the bramble, among the maladies that attack the cereals, but rather as so many pests inflicted on the earth. Mildew,319 a malady resulting from the inclemency of the weather, and equally attacking the vine320 and corn, is in no degree less injurious. It attacks corn most frequently in localities which are exposed to dews, and in vallies which have not a thorough draught for the wind; windy and elevated spots, on the other hand, are totally exempt from it. Another evil, again, in corn, is over-luxuriance, when it falls to the ground beneath the weight321 of the grain. One evil, however, to which all crops in common, the chick-pea even, are exposed, is the attacks of the caterpillar, when the rain, by washing away the natural saltness of the vegetation, makes it322 all the more tempting for its sweetness.

There is a certain plant,323 too, which kills the chick-pea and the fitch, by twining around them; the name of it is “orobanche.” In a similar manner, also, wheat is attacked by darnel,324 barley by a long-stalked plant, called “ægilops,”325 and the lentil by an axe-leafed grass, to which, from the resemblance326 of the leaf, the Greeks have given the name of “pelecinon.” All these plants, too, kill the others by entwining around them. In the neighbourhood of Philippi, there is a plant known as ateramon,327 which grows in a rich soil, and kills the bean, after it has been exposed, while wet, to the blasts of a certain wind: when it grows in a thin, light soil, this plant is called “teramon.” The seed of darnel is extremely minute, and is enclosed in a prickly husk. If introduced into bread, it will speedily produce vertigo; and it is said that in Asia and Greece, the bath-keepers, when they want to disperse a crowd of people, throw this seed upon burning coals. The phalangium, a diminutive insect of the spider genus,328 breeds in the fitch, if the winter happens to be wet. Slugs, too, breed in the vetch, and sometimes a tiny snail makes its way out of the ground, and eats it away in a most singular manner.

These are pretty nearly all the maladies to which grain is subject.