"What form of insect Is the parent of the slugs so destructive to Pear and Cherry leaves? Is there any preventive for the nuisance? The dusting with ashes or lime, or drenching with tobacco water, to be effectual, moat be repeated after every rain, if not more frequently, and where large and tall trees are affected, is but an imperfect remedy, besides being a very laborious one. Sudgosiber.

Prof. Harms describes the "Slug Fly" under the name of Selandria Cerasi, as follows: "The Slug Fly is of a glossy black color, except the first two pairs of legs, which are a dirty yellow or clay color, with blackish thighs, and the hind legs, which are dull black, with day-colored knees. The wings are somewhat convex, and rumpled or uneven on the upper side, like the wings of the saw-fly generally. They are transparent, reflecting the changeable colors of the rainbow, and hare a smoky tinge, forming a cloud or broad band across the middle of the first pair; the reins are brownish. The body of the female measures rather more than one-fifth of an inch in length; that of the male is smaller. In the year 1828, I observed these saw-flies on. Cherry and Flam trees, in Milton, on the tenth of May; but they usually appear towards the end of May or beginning ot June. Soon afterwards some of them begin to lay their eggs, and all of them finish this within three weeks, and disappear. Their eggs are placed singly within little semicircular incisions through the skin of the leaf( and generally on the under side of it On the fourteenth day afterwards the eggs begin to hatch, and the young slug-worms continue to come forth from the 5th of June till the 20th of July." They attain their growth in twenty-six days, leave the trees, and burrow in the ground.

In sixteen days their transformation is completed, and they emerge from the ground in the fly state, and commence to lay eggs tot another brood. We have not often, however, more than one brood in one season.

We know of no better remedy than dusting with lime or ashes, and this we admit to be somewhat difficult in the case of large trees. Among the nursery rows we use dry, fine earth, as we get it among the trees; and it answers the purpose.

THE August number of the Horticultural is received, snd your answer to a subscriber si Elkton, Todd Co, Ky., relative to some diseased Apple twigs seat you, I do not wish to be troublesome, bat would be glad to hear farther from you, relative to the disease known with y a, as fire-Might. What we call are-Might In the West, may differ from what Is known as that disease with you. Is the wood ss well ss the fbuage killed In Are-blight, as far ae the disease extends? (1)

In the diseased trees, of which I sent you a specimen, The foliage alone Is kitted, although the wood, and sasnettsnes the (rait, Is covered with fhe same sorts of deposit. The wood does not appear to be injured by it, but remains ptamp and healthy, and with a firm belief that it was the work of sn insect, I have pat in thousands of grafts, which were eorered with It at the time. The older and torn thrifty trees are more liable to be attacked than others; of both the . Apple and the Pear. However, I have noticed tome exceptions to this rule. J. S. Dowxes, - Elton, Xy.

(1) It is; and, as a general thing, the woody portion of the tree is affected with the disease, beyond recovery, before a leaf turns black. The first indication of the disease is often the sour smell which it emits, especially when a tree is first taken and is yet full of sap. It seems to operate principally on the newly-formed parts immediately under the bark. It spreads among the circulating fluids with great rapidity, so that a tree may in fact be dead without a leaf being withered or black. If the attack is discovered early, and the affected branch or portion of bark be cut cleanly and thoroughly out, leaving no trace of the disease, the tree will recover.- - We have ourselves saved a large number of trees in this way; but if neglected a day, or in some cases a few hours, the disease becomes deeply seated, and the tree is in a hopeless case. - Sometimes, as the subject is more or less susceptible, the leaves turn black immediately; while in others, where a portion of the wood remains sound enough to keep up a sort of communication between the roots and leaves, the latter will remain green, or a sickly-looking green,-for\a whole season. In some cases trees recover without any aid.

These are when the circulation of the fluids is very slow, as in old or stunted trees; the disease attacks a branch or portion of the tree, and expends its venom without affecting the principal channels in which the vital fluids circulate.

Answers To Correspondents #1

Please answer the following questions in the next BorUoutturiet, and yon will much oblige, at least one of your subscribers, viz: What are the names of the six best Verbenas - as for color, Ac What are the names of the six best Dahlias - as for color, habits, etc. What are the names of the six best Paeonles - as for color, habit, etc How do you protect tall sown Lettuce? "Which is the nicest Rose; "Blanche," or, Blanche Vlbert, (of the Bemontants) G. H. H. - Collins Centre, N. Y.

Six Best Verbenas, (Old oa New.) Defiance - light fiery scarlet St. Marguerite - rosy crimson with a violet center. America - pure white. Blue Bonnets-deep blue. Painted Lady - clear white, with a carmine eye. Madame Lemounier - distinctly striped like a Carnation, rose and blush.

Six Best Dahlias. Agnee - pure white. Grand Duke - bluish lilac; a new color and beautiful form. Sir R. Whittingion - ruby crimson. Beauty of the Grove - -buff, edged with purple. Claudia - violet purple, tipped with white. Mr. Hanean - yellow, tipped with white.

Six Best Chinese PARonies. Comtede Parie - purplish rose; early. Ducheue de Nemoura - violet and lilac Feativa - pure white, center marked with red. Humei - purplish rose; late. Pottsi - dark purplish crimson. Queen Victoria - rose and blush.

Protect fall sown Lettuce by a thick covering of dry leaves, laid on in a dry time. An old hot bed frame placed over them and covered with boards or straw mats would be better.

We do not know a Remontant Rose "Blanch." Blanche Vibert is a pretty white variety, but I fingd my Apple seedlings much damaged by the wooly aphis. To me it is a new enemy, and threatens to be very formidable. 1 found a few on my two year old grafts, those I destroyed by crashing them. They injure the root by caoslngit to be eorered with knots. Can yon, or any of your correspondents give any information with regard to it - any preventives or remedies? It is not confined to this locality; I hare seen them in great numbers In other nurseries. Enclosed I send you a piece of seedling root with the knots on it caused by them. W. H O.-Pwin fan.

We have seldom seen the roots of healthy, rigorous, Apple trees, attacked with this insects but seedlings allowed to remain in the seed beds until they become stunted, very often are, and so. are the roots of large trees in some unfavorable situations. The past dry season has favored the appearance of this insect we believe. Seedlings badly affected should be destroyed, the roots of older trees should be stripped and cleaned with a brush. Will some one give more information.

I SEND you by Express a small box of Apples. What are they ? I hare not been able to Identify them by any of the descriptions of Fruits in any book that I hare seen. I have been disseminating to some extent in this part of the country, as Sweet Non-such, they are a favorite here.

The small Apple was received from PRINCE, & Co. a few years since, for the King of Pippins. Is it not Bullock's Pippin? Let me hear from you through the HoriicuLIurUt. JOHN RiChaRd. - Arch Spring, Md.

Ribston Pippins, and fine specimens.

Answers To Correspondents #1

A Correspondent desires us to give a plan of a greenhouse or conservatory for professional men or the better class of farmers. We shall do so as soon as possible.

Answers To Correspondents #2

(G. F. S., Battle Creek.) By the portion of a leaf and the description sent, your Strawberry would appear to belong to the "Boston Pine," but for your assertion that the fruit is "much more delicious than Burr's Pine," which in our opinion the Boston Pine never is. Send us a few berries at the proper season, and you shall have a more decided answer.

(T. M.) If you want a rapid, even rampant grower, plant in tolerably rich soil the Wistaria Sinensis, and give it time to get a good root It exhibits best its rare beauty when trained up the trunk of a tree, or better still, a strong pole or upright wire trellice, so that many of its smaller branches may hang loosely in "graceful negligence." Exposed to the light on a trellice the flowers are of a brighter color than when in the shade. If the young shoots are pinched back in the spring, this plant will flower again in the fall. Framed on the walls of a house to extend round several sides, a succession of flowers, commencing from the warmest aspect, may be had for weeks. The honey from the flowers is poisonous to bees and bumbles.

(J. H. B.) The vine you find so much to resemble the Grape in leaf and habit is the Ampelopsis cordifolia; it attains a great size, running over the highest trees in the man ner of the wild Grape. It is not considered either useful or particularly ornamental, but it is curious for its remarkable "imitation," if we dare to use the word, of a productive vine;