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 *tion which is shaken out of the ears and sheaves before they reach the barn, the proportion of ergot in the whole crop has been estimated so high as a fourth or even a third. In Sologne the disease was farther observed by Tessier to be always most prevalent in the dampest parts of a field, and to affect above all the first crop of fields redeemed from waste land, or from land which had previously been for some time in pasture. The same connexion between moisture and the development of the ergot has been repeatedly traced in other parts of France, as well as in Germany. And according to the experiments of Wildenow, it may be brought on at any time, by sowing the rye in a rich damp soil, and watering the plants exuberantly in warm weather.

Opinions are much divided as to the cause and nature of the spur. It had been conceived by some that nothing else is required for its production but undue moisture combined with warmth; and that under these circumstances the spur is formed simply by a diseased process from the juices of the plant. By others, such as Tillet, Fontana, and Réad, who also consider it to be simply a diseased formation, it has been held to arise from the germen being punctured when young by an insect; and in support of this statement, General Field says he saw flies puncture the glumes in their milky state where spurs afterwards formed, and imitating the operation with a needle obtained the same result. On the other hand, Decandolle, reviving a previous doctrine that the spur is a kind of fungus, conceived he had given strong grounds for believing this excrescence to be a species of sclerotium, which he terms S. clavus. Wiggers supports this doctrine by chemical analysis; for he endeavours to show that the basis of the structure of the spur is almost identical in chemical properties with the principle fungin. Lastly, the most recent researches, those of Smith, Queckett, and Bauer, founded chiefly on microscopical observations, tend to a union and modification of these two views,—namely, that the great mass of the spur is a peculiar morbid formation, and that the whitish bloom which covers fresh specimens consists of a multitude of microscopic fungi in the form of sporidia, which thickly envelope and impregnate the parts of fructification in the nascent state of the embryo, and are in all probability the exciting cause of the morbid degeneration of the pickle.