the centre of which the shoot is placed, upon a little hillock of earth, with its roots carefully spread out. The whole is then carefully covered with earth and with a small quantity of manure. The air must be allowed to penetrate the bed, this being secured by stirring up the soil from time to time.

Care must be taken to destroy or remove snails, insects, and other things injurious to the plant. In October, during dry weather, the stems of the asparagus are to be cut at a height of about six inches above the surface of the ground. A small quantity of manure is then to be placed around the plant and covered with a thin layer of light earth, so as to form a little hillock around the shoot some inches in height. The same precautions are to be taken each year; but it is not until the fifth year that the asparagus can be collected to advantage.

The shoots should be gathered once or twice a day, preferably in the morning, and should never be cut, but should be bent a little downward and then slightly twisted, thus detaching the top readily from the stump. By taking all the necessary precautions, especially in preventing too great action of light upon the asparagus, plants of extraordinary dimensions and excellence can be obtained, varying in price in Paris from one fourth of a franc to five francs each. A single plant has been known to furnish five dollars' worth of asparagus in a single year. When it attains, as it sometimes does, an excessive growth, the plant loses its original form and becomes very much flattened, the edges curling round in the form of a half-closed tube. This is technically termed fasciation, and frequently occurs in other plants.-13 B, July 10, 81.

NEW DISCOVERY IN CONNECTION WITH THE POTATO DISEASE.

There has been hitherto one "missing link" in our knowledge of the life-history of the potato-blight-Peronospora infestans. The non-sexual mode of reproduction by gonidia, or zoospores, has long been known; but the sexual mode of reproduction has eluded observation. This link has now 'been supplied through the researches of Mr. Worthington Smith, who described his discovery in a paper read at the last meeting of the Scientific Committee of the Royal Horticultural Society, and published at length in the Gardener's

Chronicle for July 10, 1875. He finds the female organs, the "resting-spores," or unfertilized." oospores," and the male organs, or "antheridia," in the interior of the tissue of the tuber, stem, and leaf when in a very advanced stage of decay; and he has actually observed the contact between the two organs in which the process of fecundation exists. In some remarks made at the meeting of the British Association last year, by one of our high authorities, it was suggested that we have in the Peronospora an instance of the phenomenon not infrequent among fungi, known as "alternation of generations;" and that the germination of the true spores of the potato-blight must be looked for on some other plant than the potato. Mr. Worthington Smith has, however, looked nearer home, and has proved at all events that the suggestion is not verified in every case.

CONTINUOUS CORN-GROWING.

Some agricultural authors insist that corn-growing can not pay in England, and that the increasing expense of cultivation must shortly consign large tracts of arable land to grass. Two spirited agriculturists, Messrs. Prout and Middleditch, of England, have helped materially to solve some of the difficulties of clay farming. They have demonstrated the agricultural capabilities of stubborn clays, for their practice shows how successfully they may be cultivated; have profitably grown cereals on the same heavy land for several consecutive years, and continue annually to dispose of the whole of the increased products. Mr. Prout's farm comprises 450 acres, and was in such poor condition that it was with difficulty rented at twenty shillings per acre. The land was wet, and was overrun with weeds and overshadowed with crooked fences. The best portions of it produced twelve bushels of wheat and twenty bushels of oats per acre per year. Since 1861 Mr. Prout has built commodious dwellings for his laborers, dug new wells, ditched and drained the whole farm, altered the fences and hedge-rows, and reclaimed the waste land to such an extent that eighteen acres have been added to the productive area of the farm. From the beginning Mr. Prout has employed steam-power, and at ev ery practical step the steam-plow so effectually disintegrated the formerly sour, stiff clay, admitting frost, air, and sun, that

after the first few years full crops grew with a little extra manuring; and even cereals were grown consecutively with the employment of about twenty shillings per acre of artificial manures. Experience, however, has shown that to prosecute his system successfully, fifty or sixty shillings per acre of manure must be applied annually.

But Mr. Prout has done more than to bring into superior and profitable cultivation 450 acres of heavy clay land, worth thirteen years ago not more than twenty shillings per acre. He has inaugurated an almost original system of husbandry. All ordinary rotations are ignored; corn crops follow each other on the same field for several consecutive years. Wheat has been grown for five successive years, and the cereals have been repeated for eight years. Mr. Prout is no mere theorist. He brought to his labors the experience acquired from many years in Cornwall and in Canada. He determined to sell, year by year, the whole of his growing crops, and to restore an equivalent in the form of portable fertilizers. For his consecutive corn crops Mr. Prout only desires deep, thorough cultivation, extirpation of weeds, and a regular supply of manure. His crops are sold a week or ten days before they are ready for the harvest, the neighboring farmers being his principal buyers, and superintending their own harvesting and threshing. The labor question troubles Mr. Prout less than many of his neighbors. His steam-tackle economizes both horse and hand labor, and keeps his labor account under thirty shillings per acre. He expends upward of £1200 annually on portable manures. Bones, mineral superphosphate, guano, and nitrate of soda are generally preferred. The average annual receipts of his farm are £4800, out of which it is estimated that he has an annual profit of £825. That the consecutive grain crops taken off have not exhausted nor deteriorated the land is evident from the improved quantity and quality of the growing crops, and the increased value of the farm, which would now bring double the price paid for it by Mr. Prout. Very few land investments, or any description of investments, pay, like Mr. Prout's, a fair interest on the outlay, and double their value in thirteen years.

The farm of Mr. Middleditch, before referred to, has been treated in a very similar manner, and with the same encouraging results.

FIELD EXPERIMENTS WITH VARIOUS FERTILIZERS AT THE
BUSSEY INSTITUTION.

The “Trials of Various Fertilizers upon the Plain Field of the Bussey Institution" of Harvard University, by Professor F. H. Storer, are much more elaborate, accurate, and useful than any other field experiments ever attempted in this country, and will, if continued, excel in these respects all European ones except those of Lawes and Gilbert at Rothamstead, in England.

The motive of these experiments has been "to determine, if possible, what kinds of fertilizers, among those ordinarily obtainable in Boston, are best fitted to increase the yield of crops grown upon a field that had been chosen as the typical representative of the thin, light, 'leachy' soils which so frequently overlie the gravelly drift in New England." The plan has been to divide the field into plots, and to raise upon them different crops with different kinds of manure, repeating the same crop on the same plot, with the same manure, year after year. Three kinds of crops-barley, beans, and ruta-baga-were grown. Yard and stable manure, muck, fish-scraps, lime, bone-meal, superphosphates, salts of ammonia, potash and soda, and other fertilizers were used, either singly or in combination with each other. The experiments were commenced in 1871, and reports for four years (1871-4) are now issued.

An idea of the magnitude of the work may be obtained from the fact that some 285 experimental plots, each five meters (about one rod) square, have been cultivated, some during the whole, and others for part of this time. The experimental crops suffered somewhat from the casualties to which crops in general are exposed, such as heavy rainstorms, depredations of animals, failure from bad seed, and particularly from drought. The repetition of the experiments through a series of years, however, served to make up for the disturbances from these causes, so that the general results are, on the whole, quite conclusive and reliable. The conclusions apply, of course, to such soils as that of the experimental field, and only in a more limited degree to

others.

In one respect, however, these experiments have a very

great value. Most of the investigations upon which the accepted theories of agricultural science are founded have been made in Europe, where circumstances obtain, in many respects, different from our own. And so long as we depend entirely upon results of European experience to guide our practice, we shall run the risk of falling into error. A number of illustrations of this truth are brought out by these experiments of Storer.

In the experiments described above it was found that potassic manures yielded the best crops, while phosphates and nitrogenous manures did but little good, and in some cases positive harm. The largest crops were obtained with farm and city stable-manure, and with wood-ashes. Nitrate, sulphate, and carbonate of potash (pearlash) likewise brought large returns. In a summary of comparative results, woodashes proved more efficacious than any other single fertilizer, the yield being larger than with either yard or stable manure.

Professor Storer concludes that the soil needed potash rather than phosphoric acid or nitrogen. "The addition of potassic manures to the soil manifestly enables the crops to make use of a certain store of phosphoric acid and nitrogen that the land contains. It is clearly shown, moreover, that the amount of available potash in the soil must be very small, since neither the phosphatic nor the nitrogenous manures by themselves, nor mixtures of the two, such as several of the so-called superphosphates are known to be, could enable the crops to get enough potash from the soil to keep them from starving after the first year." And further, "It is plain that the soil of this field, like those of thousands in New England, needs fertilizers that are rich in potash, and that, under the existing condition of things, no advantage can be gained by applying mere phosphatic and nitrogenous fertilizers to the land.... If only potash enough be given to this soil, the latter can of itself supply all the other ingredients that compose the food of plants, at least for the term of years during which the experiments lasted, and for as many more, of course, as the store of phosphates and nitrogen may hold out. . . . The crying want of the land is for potash, and potassic manures should be applied to it to the well-nigh complete exclusion of all other fertilizers until an equilibrium can be reached."