Referring to the potato disease, an admirable treatise before us says:

"From what has been said it follows that the parasite may often live over winter in the tops or decaying tubers left in the fields after harvest. Prudence would, therefore, dictate the complete removal and destruction of such refuse. It should be buried or burned".

There should be no objection to this. It is certainly no harm to burn fungus spores. But we are inclined to think the recommendation prevents students from looking into the cause of disease from fungus operations. All that we may burn on a whole crop of potato stems will be but as a drop in the bucket, as compared with those that escape the burning. As the same good treatise says, speaking of the first appearance of the potato disease:

"A critical inspection of the diseased tops shows numerous small white spots scattered over the leaves and stems. When highly magnified these spots are found to be miniature forests of slender stems growing up out of the surface of the leaves and stems of the potato. These tiny stems commonly branch and swell out at the ends into ellipsoid or oval bodies, known as summer spores. These little spores are produced by millions and are so small that a million could easily lie side by side on a square inch without crowding. When ripe they separate from the stem by a joint and fall".

Such tiny organisms scarcely "fall," but are borne away everywhere on atmospheric currents.

From their immense number we may regard them as almost omnipresent when they once get a foothold in any locality, and the burning of a few million of no account whatever. Yet the disease, virulent in one season, will often not appear the next or perhaps for many successive years. Why? Not because the spores have been destroyed, but because the conditions for their germination have been unfavorable. We may never hope to " stamp out " these plagues, but we may hope to learn something about the favorable conditions, and then perhaps control them.