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considerable size and age, as their decayed trunks testify. The extensive forests then existing were sufficient to break the force of northers before they reached the latitude of the Gulf States; and, of course, the moist atmosphere maintained by these forests tended to equalize temperatures. How great an influence these northers may exert on a southern climate, even in the partially-wooded districts of the East, is plainly exhibited in the devastation by frost at St. Augustine, Fla., on Feb. 9, 1835, when orange-trees two feet in diameter, and a century old, fell victims. Now this fruit is not considered sure above latitude 29°, though cultivated much farther north in protected localities. The planting of forest-trees cannot be too strongly advised: the subject is one of not merely local, but of national importance. It is, moreover, quite easy to prove it a profitable operation. But we Americans are at present very nomadic in our habits: we occupy land for its immediate advantages, and are rarely inclined to commence improvements that require half a century or more for their accomplishment.

With regard to vegetable nosology, we can only say that too little is known of the nature of vegetable life for a systematic and theoretical treatment of the diseases to which plants are liable. It may be that they possess the faint foreshadowings of a nervous system, and are liable to other than mere mechanical injuries. The microscope gives us, I believe, no direct indications that such is the fact; but the curious action of certain socalled narcotic gases, which cannot injure the tissues, and the effects produced by vegetable poisons, are difficult of explanation without admitting a degree of nervous excitability. However this may be, we should remember that most of the curatives recommended are the results of blind experiment, and that much difference of opinion exists as to their value, and mode of application; and, finally, that the old adage, "Prevention is better than cure," is worth as much now as it ever was; and that we shall do well to protect our plants in every manner possible from all injurious influences that may generate or develop disease. D. M. Balch.

Salem, Mass.

THE WESTERN PRAIRIES: THEIR COMPOSITION, CLIMATE, PRODUCTS, AND PROSPECTIVE CONDITION.

In considering the capacity of the prairie-soil for the growth of arborescent and horticultural products, we must first learn its constituent elements, and ascertain wherein it differs from other soil-formations. The conflicting opinions must be made to harmonize, or we shall fail in presenting any thing like a uniform rule for its general culture.

We talk of prairie-drift, of the glacial epoch, of submersions and upheavals; of treeless plains fringed with forest-belts, where the rivers, like great dead furrows, drain the land; of island-groves that stand like gems in the great sea of prairie-verdure; of jutting points of arborescent growth that break the monotony of the prairie, that, swell after swell, stretches beyond the range of vision.

Is this prairie-formation of one uniform texture, a homogeneous mass laid down by the waves of the old Silurian seas? or have some of them been formed at different epochs and of various material? The answer to this question will tend to throw light upon the subject, and to account for what some people please to call vagaries of the prairie-soil.

At the East, we have a general classification of soil, with its system of culture; but here on the prairie we have a general idea that the prairie-formation is due to one cause, and that it must be of a pretty general character. People begin to admit that there are peculiarities in regard to it that need further investigation, and are less disposed to trust to luck for a crop than formerly.

The first step in the way of the successful culture of horticultural products is to classify the soils, and study their relative value for particular products. Of course, climate will have more or less to do with this when we take in the whole range of the State, which is varied from semi-tropical products to those of the north temperate zone.

The lead-region of Galena contains no drift; its highest peaks being capped with Niagara limestone, and the valleys cut and carved into their present shape by the erosion of ocean and river currents.

Northern Illinois is covered with a thick band of blue clay, resting in some cases on the lower and in others on the upper silurian strata, over which is spread the drift of the glacial epoch, with its beds of gravel, and boulders of granite, from the copper-regions of Lake Superior. As we proceed south over the coal-fields, this band of blue clay thins out, and the drift becomes a friable clay-loam of considerable depth, interspersed in places with thin sheets of sand, in which is found an abundant supply of water, at a depth often to thirty feet. In other places, the drift is homogeneous, and wells must be sunk to a great depth. In fact, so variable are these prairies, that each location must be carefully examined before we can determine its relative value.

At one time, this drift may have been of a uniform character; but by erosion from ocean-currents, and the refilling of these ocean-grooves at a later period, many account for the marked variation in the character of the present surface within short distances.

We have, along the rivers, alluvium, loess, and drift; while the great inland prairies are composed of drift from fifty to one hundred and fifty feet in depth. The timber-lands of the small streams are of the same general character. The underlying rock, therefore, has nothing to do with the surface-soil, otherwise than in its deep subterranean drainage.

The emigrant from the East has little idea of the difficulties that he must encounter, and looks upon this formation as he would upon the alluvium of his native rivers, that is composed of the debris of rich rock-soil washed from the hillsides and cultivated fields of the adjacent country.

In the distribution of rain, different parts of the prairie receive unequal quantities; and this, too, must be taken into consideration. Add to this, currents of air from the north-west, sweeping down from the polar plains without warning, and the almost steady presence of the damp air-currents coming up from the Gulf of Mexico, which cause new complications that must be taken into account .

This is the skeleton or framework, the vascular system, upon which we have to build.

The surface-soil, composed of the remains of plants and insects, is from one to four feet in depth, and almost practically inexhaustible when under very indifferent management.

While the timber-lands of the East have had their climate changed by stripping the hills of their forest-growth, and exposing the country to sudden changes of temperature and to long-continued droughts, we of the prairies have begun at the bottom round of the ladder, and must perforce ascend. We have forests to build up, not to cut down. Every tree we grow, every shelter-belt which we plant to shelter our stock, our crops, or our orchards, has its influence in modifying the climate, and in giving us a more generous supply and equable distribution of rain. We find the loess soil of the large rivers eminently adapted to the grape, the pear, the peach, and certain varieties of the apple; while the peach, the pear, a few varieties of the early apples, the strawberry, the raspberry, and the blackberry, flourish on the hills of the grand chain, in the south part of the State, by the side of cotton and other semi-tropical plants, fruits, and nuts. Central Illinois is the great plateau or corn zone of the West, and also well adapted to the culture of the whole range of small fruits, apples, pears, with fair crops of the peach, say, in three out of four years. Vegetables do very well in most parts of this section, but, on the whole, are not as sure a crop as in the soils of the north part of the State.

In variety of products in soil and in climate, this State can challenge any State in the Union.

The immense water-power in the north part of the State, the extensive coal measures of the centre and south, the belt of navigable rivers that girt her round and penetrate the interior, the lines of railroad that radiate from her great centre, all point to the fact, that, at no distant day, she will have to supply a dense population engaged in manufactures, in commerce, and in mining; that all points to the north will demand at her hands early fruits, early vegetables, and the long-keeping apples. These demands will and are already stimulating her industry in the productions of the garden and the orchard, and will give her a commanding position in the higher departments of rural pursuits. M. L. Dunlap.

Champaign, Iii., Jan. 20, 1867.

THE MAGNOLIACE^E.

(Continued.)

As the production of new and improved varieties of fruits and flowers has become a systematized art, capable of unlimited extension, it is probable that the time is not distant when the Magnoliacece will be submitted to its operations. The certainty with which the glauca matures every seed of the germs adapts it as a pistillate parent for that purpose. An application of the pollen of the purpurea might develop a progeny with red or variegated flowers. Increased size of flowers and foliage might be secured by the pollen of the macrophylla, as has already been effected by a cross with the tripetala, resulting in the production of the Thompsoniana. Interesting results might follow the fertilization of the glauca by the acuminata, and the latter by the macrophylla.

While pursuing this subject, it would be well to test by experiment the effect of crossing the tender grandiflora with both the glauca and acuminata. The progeny between the tender rhododendrons of the Himalaya Mountains and the hardy American species are in some instances sufficiently hardy to bear the climate of Cleveland. One of them has stood fifteen years on the north side of my residence, overlooking Lake Erie, and has never received any protection during winter. It not only survives, but is thrifty and healthy. May we not expect some of the progeny from the crosses above suggested to be endowed with an equal degree of hardiness with those hybrid rhododendrons?

4. M. Longifolia. — This is a mere variety, resulting from breaking the 1 natural habit of the glauca, its parent. It originated in Belgium, and was supposed to be an accidental cross between the glauca and tripctala. None of the features of the latter are exhibited in its habit; and it differs from the former only by its larger flowers and leaves, — differences capable of perpetuation by seed, which it produces in equal abundance with its parent . It is also improved by propagation on the stock of the acuminata.

5. M. Thompsoniana. — A doubt can hardly be entertained that this is a true hybrid between the glauca and tripetala: though Loudon considers it a variety only of the glauca, "the aboriginal species enlarged in all its

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