By Dr. Byron D. Halstead. Reprinted from the proceedings of the Connecticut State Board of Agriculture, 1882.

Horticulturists and agriculturists are not yet fully awake to the immense amount of injury they suffer from the minute plants of the lower order of vegetation known as microscopic fungi. It is barely a quarter of a century since not merely practical men, so-called, but even men of science firmly believed that fungi never existed except on diseased vegetation. Scientific men teach us differently now; but there are some excellent practical men, who still doubt whether these little plants are the cause rather than the followers of disease. It is an extremely important question to the practical man. If these almost invisible plants be not the cause of disease, it is not worth while to care anything about them ; but if they be, then we must wage war on them, and the best knowledge in an attack on an enemy is that which relates to his habits and all his secret ways. This chapter by Mr. Halstead is well worth reading, both by the true believers in deleterious fungus agency, and by the infidel. The former will perceive how much is yet to be added to the knowledge we have already gained; the latter may point to the differences of opinion among learned men, but will surely see that something has been gained over old notions, and that at least it is time for him to go over the ground anew.

He may ask himself why, if smut and similar organisms be a fungus, and yet not the cause of disease, why he has been for just two hundred years this season, as Prof. Brewer tells us here, trying to destroy it by steeping his seeds in brine, copperas and all sorts of steeps and washes?

An interesting discussion followed Mr. Hal-sted's remarks on the ergot (Claviceps purpurea) and the smut in Indian corn (Ustilago Maydis). It is beyond dispute that ergot has powerful medical properties; but we find by this discussion that abortion in cows is claimed for the smut as well as for the ergot by the farmers in Connectient. It is but fair to say that after balancing the points brought out by the discussion, the smut seems at least more innocent than they suppose.

A very interesting inquiry is suggested by the discussion, namely, how do the spores of fungi enter the plant? The prevailing impression with leading mycologists is that they germinate on the exterior, and then grow into the plant, penetrating the structure as they grow, just as a mistletoe or other parasitic plant penetrates the tissue as it grows. From some of the remarks of Mr. Halsted it may be surmised that this is his view, though he remarks that the early growth of the spores, from their small size, has never been observed in plant tissues. But we very often learn from circumstantial evidence, as well as from direct observation of the facts; and, if we may say that it is improbable that a spore could be taken into the tissue through the roots, and travel through the structure from cell to cell, as moisture does, by endosmose action, so also may we say, from observations recorded in this paper, that it seems improbable in many cases that the spores should have reached their germinating points from an external starting place on the surface of the inflorescence.

The intelligent and careful reader of this excellent paper will feel that he has profited largely by the perusal, but still with the encouragement which the explorer loves to enjoy, that there is yet much to learn.