A Frankford (we believe Pa.) correspondent says: "Enclosed I send you a piece of bark from a twig on a Bartlett pear. Will you in the Gardener's Monthly please to explain the nature of the disease if disease, it is; and the cure, if cure there is? I find that it causes the smaller limbs to die slowly, and gives the tree a stunted or premature appearance. My trees are much injured by a short, green, big-headed slug that eats away the tender portion of the leaves from the upper side, and leaves only the woody fibre. Can the ravages of this vile thing be prevented or stopped? By causing the trees to put out a second growth of leaves, I have blossoms in the fall and no fruit next year."

[The disease shows itself in blackened leaves, and in black splotches in the growth of the past year, as the leaves are growing in spring. We have always identified it with what is known in the books as "Frozen sap blight," though we are quite sure frost has nothing whatever to do with it. As our correspondent says, it is very likely to appear on branches that have had the leaves prematurely destroyed by the leaf blight of the summer previous. As leaf blight is a fungus, it is quite likely the "frozen sap blight" is a phase of development of the same fungus; but of this we have no certain evidence. For the leaf slug see article in another column. - Ed. G. M.]