A correspondent suggests that " one feature of action, in working of shelter overhead as a preventive of grape mildew, has not been touched, and that is, radiation of heat. It is well known that a plant radiating to the open sky cools off in half the time that another will when slightly sheltered by the projection of a wall. May there not therefore be more in the retention of heat, and more gradual cooling off produced from the coping shade, than in the prevention of dew ? The value of these projections was known more than one hundred years ago, written upon, and practiced."

The discussion on Grapes, at the las Ohio Pomological Society's meeting, gave the Ionaa rather a bad character. Its hardiness was doubted, while a tendency to mildew and rot came forward as one of its characters in a majority of the reports. We think the manner in which a majority of the vines have been propagated has much to do with the tendency to disease reported, and believe that when plants are grown only from healthy, well-ripened buds, and have an opportunity to develop the full character of the vine, that it will prove a hardy and valuable grape - not perfection, as has been claimed for it, but one that few cultivators can do without.

Who Knows About it? - It was written, some twenty years since, that at Walpole, Mass., a peach had been grown from seed more than forty years without variation in size or quality, any more than if budded It was called the "Allen." Who knows anything about it?

Plants in hot-beds are often destroyed by a too great heat, more especially on a clear, sunny day. Care should be taken to raise the sash, and to let in as much fresh air as possible, consistent with keeping up a requisite degree of heat for plant-growing. If one side of the sash only can be raised, on account of too great cold, let it be the upper side.