is the result of immigration from the South, and that it dies out every year with its food-plant, the eggs which it lays not coming to maturity, being killed by the inclemency of the weather. He finds testimony that, for many years after the introduction of the cotton-plant into the Southern States, the cotton-worm did not appear, and that its existence in Southern Alabama but little preceded the late war. It is, however, capable of extended flights, as it has been observed in the Eastern States and also at Buffalo and Chicago. The supply of the insect is therefore maintained every year by means of flights from the South, which are somewhat capricious, and may be diverted out of their course by powerful currents of wind occurring at the time of their migration.

The inference drawn from these facts by Mr. Grote is that the process of artificial extermination may be simplified by limiting the period during which it can be successfully attacked, and by doing away with a certain class of proposed remedies. The agent employed to destroy the worm must be used against the first brood, as it appears in any given locality during its progress northward, and that, to be ef fectual, the action must be concerted in the application of the remedial agent.

Mr. Grote strongly recommends the introduction of the English sparrow, and additional legal protection to insectivorous birds, as absolutely necessary to the agricultural interest.-5 D, Dec., 1874, 726.

HORSE-POX.

M. Depaul describes what he calls horse-pox in horses, the symptoms manifesting themselves in fever, prostration, a certain elevation of temperature, cough, engorgement of the submaxillary ganglions, and in having in the nostrils of the left side a series of circular projecting pustules, depressed in their centre and exhibiting characters similar to those of variole. These pustules form a distinct eruption on all parts of the body.

The experiment has been made of inoculating a child and a heifer with this substance; but the result has not yet been announced.

M. Bouley, the eminent veterinary surgeon of Paris, remarked, in the presentation of this communication to the

Academy of Medicine of Paris, that the facts were far from being exceptional; that that very morning he had found the same thing in a horse which was supposed to be affected with glanders. He stated that, in view of the possibility of confounding the two, the propriety of experiments, including children, was open to very grave doubts.-12 B, May 15,

422.

DRY ROT OF THE LEMON.

A serious malady has lately attacked the lemon-plant in various parts of the world, the result, as suggested, of the forced cultivation of the fruit. This is known as the "dry rot," and commences at the extremities of the plant or of the roots, and gradually spreads throughout the whole tree, drying up the sap in its course. It is suggested that by grafting cuts of the wild lemon-plant on the orange-tree a new stock may be obtained, and the fruit cultivated upon trees which have not been subjected to a forced growth.-12 A, April 6, 1875, 456.

PRESERVATION OF FRUIT.

The following method for the preservation of fruit has been patented in England. The fruit is placed in layers in a vertical vessel, separated by layers of pulverized white sugar, and is then covered with alcohol of 80° Gay Lussac. After twelve hours the closed vessel is inverted, and the maceration allowed to continue for twelve to seventy-two hours, according to the nature of the fruit, which is then removed and allowed to drain and dry. About two pounds of sugar and two pounds of alcohol are recommended for four pounds of fruit.-5 C, XXXII., 248.

NEW KIND OF SPINACH.

Several years ago a new kind of spinach was introduced into England, under the name of Australian spinach (Chenopodium auriconium), which, according to the unanimous opinion of connoisseurs, must be regarded as a valuable acquisition. It is perennial, very hardy, reaches a height of six inches, and affords a large quantity of tender leaves, which are soon reproduced after plucking. Its flavor is similar to that of common spinach, but not so grassy nor so harsh, and,

in general, finer. It is best prepared by throwing the leaves into boiling water, and, after pouring this off, cooking it as usual. Its cultivation is simple. The seed may be sown in a hot-bed in March, for subsequent transplanting, or in the open ground in April or May.-9 C, December, 1874, 183.

BEST SHAPE FOR FRUIT-TREES.

The majority of a convention of German pomologists expressed a decided preference for the pyramidal form for fruittrees. The advantages claimed for it are the minimum of shade, greatest strength, avoidance of severe wounding of the tree, production of better fruit, and at the same time fewer disadvantages from storms, weight of snow, excess of fruit, theft, etc.-5 C, July, 1874, 105.

NEW FACTS IN THE HISTORY OF THE POTATO BLIGHT.

An important step has been gained in the natural history of the potato blight. It is stated that Professor De Bary, of Strasburg, has detected the existence of "heteræcism," or an "alternation of generations," in the life history of the Peronospora infestans, the parasitic fungus which causes the disease. It is conjectured that the second form may possibly be found on clover.

INVESTIGATION OF THE POTATO DISEASE.

Announcement has already been made of the selection of Professor De Bary, of Strasburg, by the Royal Agricultural Society of England to make a series of investigations into the life history of the potato fungus, for the purpose of filling up a certain blank in our knowledge of the development of this destructive object. This gentleman, in carrying out his investigations, has lately discovered that the disease is not propagated by defective tubers, and that although the mycelium was distinctly apparent in the stalks of plants raised directly from diseased tubers, yet that neither gonidia nor germs were evolved. He also expresses the hope that he has at last discovered the resting-places of the oöspores, or the active primary germs of the fungus. This is the special point upon which further information is needed, and may suggest the proper means of preventing the continuance of the disease in any given locality by warning agriculturists

against planting their potatoes in a spot where they must, at some time, inevitably be destroyed.—18 A, Nov. 20, 1874, 239.

FARLOW ON THE POTATO ROT.

A few years ago Dr. W. G. Farlow, of Cambridge, Massachusetts, visited Europe for the purpose of making a special study of the cryptogamic plants, and in this connection spent considerable time in the study of the subject, under the eminent Professor De Bary, of Strasburg. A recent number of the Bulletin of the Bussey Institution contains some of the results of this move on Dr. Farlow's part in an elaborate paper upon the potato rot. This is an important contribution. to the natural history of the subject, embodying as it does the latest knowledge of this most destructive pest.

It should be remembered that Professor De Bary was commissioned by the Royal Agricultural Society of Great Britain to carry on investigations in this department, and the labors of Dr. Farlow give the results hitherto ascertained.

There are still some points in the natural history of the potato rot which are unknown, and which must be determined before any very positive preventive measures can be entered upon. Dr. Farlow sums up the whole matter by stating that there is no such thing as a specific against it; that is to say, there is nothing that will effectually protect the tubers and also prevent the further development of the fungus, as whatever completely destroys the fungus will be equally fatal to the potato itself; so that the only thing that can be done is to prevent as much as possible any harm to the plants in which the mycelium already exists, and the spread of the disease to healthy plants.

If the moisture in the air, about the time when the disease is likely to appear, say from the first of July to the middle. of September, can be controlled, the mycelium would not increase to any extent so as to produce practically any harm. Unfortunately this can not be done; but the land can be thoroughly drained, or dry soil used for planting. The wetter the soil the more liable is the potato to rot. As the disease does not appear until about the first of August, early potatoes should be less likely to rot than late ones. But exactly what variety farmers should plant is not a question for the botanist. Although certain potatoes seem to resist the

H

disease better than others, yet none are free from liability to decay. Dr. Farlow remarks that the precautions which should be taken to prevent the extension of the disease will be more definitely known when the plant in which oöspores are produced has been discovered. At present we can not say with certainty that these are found either in clover, wheat, oat, or rye straw, and therefore the prohibition to plant after any of the above-mentioned crops is without foundation. It is thought probable, however, that the oöspores of Peronospora infestans will be found concealed in some common plant eaten by cattle; and as these oospores are so tough as not to be affected by passing through the alimentary canals of animals, the chances of avoiding the rot are greater when mineral manures are made use of than animal. Dr. Farlow also puts in a word of caution in reference to the fungus of the lettuce, which he states is increasing very rapidly in New England, and is a subject worthy of serious consideration.

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CULTIVATION OF THE ASPARAGUS IN FRANCE.

There are few vegetables in which the result of special care in cultivation has been more marked than in the case of asparagus, which, from the old-fashioned stringy, slender, and tough spike, has been converted into a tender, succulent mass of agreeable food. This result is due particularly to the labors of the French, asparagus having been cultivated in France for a long time, especially in the vicinity of Argenteuil, near Paris.

In former times the beds in which this plant was culti vated were managed without reference to other crops; but more recently the plant has been reared in the vineyards, the grape and the asparagus agreeing very well together. At present the vineyards of Argenteuil furnish from eight to twelve hundred dollars' worth of asparagus annually per hectare (2 acres), or from three to five hundred dollars' worth per acre.

The asparagus bed is started in March or April, with shoots obtained by sowing under glass in open, light, wellworked soil, isolated as much as possible from surrounding vegetation, the earth being dug out to the depth of about eighteen inches. Trenches of these dimensions are first prepared, being separated from each other about four inches, in