throat pervious; blue, with yellow flowerd flaxes; and so in many other cases. Such is the substance of Gartner's views. In calculating beforehand the probable result of an experiment, it may be as well to bear in mind that upon the whole the cross breed may be expected to resemble its male parent more than its female. Mr. Knight raised, between a sweet almond impregnated by a peach, a cross that, in every respect, presented the character of a perfectly melting peach (physiol. papers, page 252). When the female azalea is set with the pollen of a rhododendron, the seed of the azalea produces plants most resembling the rhododendron; and we think that the balance of evidence undoubtedly turns in this direction.

M. W. Herbert states that he had produced numerous hybrids upon certain species and varieties of the Lily, which resembled the female parent in the stalk and leaves, but the male in the peculiar characteristics of the flower.

It frequently happens in gardens that there are spontaneous crosses, which may be attributed to divers accidental causes-as proximity of flowers-pollen being borne from flower to flower by insects, bees, wasps, etc., etc. These spontaneous crosses happen most frequently in the Cruciferæ Double flowers like the chrysanthemums are always sterile, and the hybrids cannot reproduce, but M Gallesia has produced double flowers by crossing semi-double, with semi-double ones, and has obtained fertile seed from semi-double and even double Ranunculus.

Hybridization has only commenced, but even as yet the most beautiful flowers are due to accident, but is it not well to investigate the laws of nature and aid them? In 1694 Camerarius spoke of hybrid plants; in 1751 Linnæus wrote his Dissertatic de plantis hybridis; and in 1759 Kolreuter commenced and succeeded in producing hybrids by artificial fecundation.

The following is a list of natural hybrids discovered in the vicinity of Vienna, and described by A. Neilreich, a minute description of which he read before the Zoologico-Botanical Association of Vienna, at its meeting on the 7th of January,

*The seeds of this plant are invariably imperfect-this fact led botanists to suspect that it was a hybrid.

Professor Gærtner, of Stuttgardt, and A. Neilreich, of Vienna, have devoted much time to the study of this subject, state that the cereals are among the plants least favorable to hybridization. Professor John Lindley, professor of Botany in the University College, London, does not regard the process by any means as impracticable, but merely difficult in manipulation-in removing the unexpanded anthers and then applying the pollen of another. Mr. Maund, of Bromsgrove, Warwickshire, (England,) obtained a prize medal at the industrial exhibition in London, in 1851, for hybrid specimens produced from the annexed varieties of wheat:

MALE.

5. Boston Red,

6. White Cone, (hairy,) 7. Dark Cone,

Large ear, very strong straw,

Donna Maria,
Northumberland Red (smooth,) Long beardless ear, rather downy

Pearl,

Small deformed white ear.

Mr. Maund found as a general rule in hybridizing wheat, that a strong male and weak female produced a better result than a weak male and a strong female.

In 1848 Mr. Raynbird, of Laverstake, obtained a gold medal from the Highland (Scotland) Society, for experiments of this kind. Mr. R. commenced his experiments in 1846, with the "Hopetoun," a white wheat, of long ear and straw, and fine grain, and "Pipers Thickset," a coarse red wheat, with thick clustered ears, a stiff straw and very prolific, but liable to mildew. The hybrids thus obtained, were intermediate between the two parents, the ears are shorter than in the "Hopetoun," and larger than in the "Thickset."

The deterioration of the saccharine qualities of the Sorgho should rather be ascribed to soil and culture than to hybridization, for the following reasons:

First. It is a difficult matter to hybridize plants belonging to different species although of the same genus ;-in a natural state there is no probability that hybrids would be produced in any event-where hybrids are naturally produced they occur in species which are very closely allied. The different kinds of Indian corn or maize are all simply varieties of one species-hence they hybridize very readily. Indian corn and broom corn belong to the same family, (graminaceae) yet no farmer hesitates to plant them side by side, well knowing that they will not hybridize.

Second. The saccharine quality of the Sorgho has deteriorated when grown in localities many miles distant from any broom corn. It is a well known fact that pollen grains are borne by the wind often for miles; but it is assuming, rather more than the facts will warrant, to assume that the wind would safely conduct pollen grains from a small lot of broom corn for a distance of many miles over hills and valleys, through forests, through many fields of corn, just as tall as the Sorgho, and then safely deposit the pollen on the pistils of the Sorgho plant.

Third. Every one who has grown Sorgho corroborates the fact that Sorgho grown on bottom lands, or very rich moist loam, invariably produces a very high stout stalk, but with not more than half the amount of saccharine matter in it than that grown on dry uplands. Several instances have come to my knowledge of the same lot of seed having been planted on rich bottom lands, second bottom and poor dry uplands, with the following results, viz: That planted on the first bottom grew the tallest, largest and rankest, with the most suckers, but required from twelve to fifteen gallons of juice to make one gallon of ordinary syrup; and the seed, planted in the same place where it grew for two or three successive years, To completely" ran out" that it produced nothing at all. That grown on the dry upland was more slender, and not near so tall, as that grown on the bottom land -but six to seven gallons of the juice made one gallon of excellent syrup. The

seeds were sound, healthy, and reproduced from year to year the same kind of cane on similar soil.

Fourth. Almost all kinds of cultivated plants from foreign countries require acclimation-some never become acclimated-others deteriorate. Many varieties of wheat deteriorate so greatly in eight or ten years as to be no longer worthy of cultivation-other varieties, as the Mediterranean for example, improve under cultivation so as to be more valuable and reliable at the close of twenty or twentyfive years than they were originally.

THE ATMOSPHERIC CONDITIONS SHOWING THE VALUE OF BAROMETERS FOR AGRICULTURAL PURPOSES.

BY C. A. RICHARD, OF COLUMBUS.

CHAPTER I.

Our first subject, in demonstrating the atmospheric conditions is, to have a close examination of the heat and moisture which are indispensable to the fertility of the earth. Without suitable arrangements for their diffusion and distribution, and within the limits of certain minima and maxima, the earth would not have been habitable, or the design of its Creator perfected.

These arrangements therefore exist, and also which, in their character are very simple, though somewhat complicated and irregular in their operation, the ultimate result is always attained.

From the operation of these few, simple, connected and intelligible arrangements for the diffusion of heat and the distribution of moisture over the earth, result all the phenomena which constitute the weather; and by studying them, we may acquire an accurate knowledge of its "Philosophy."

The necessary heat is produced mainly by the direct action of the sun's rays; and the most obvious feature in the arrangements for its diffusion is that which the sun is made to shine successively and alternately upon different portions of the earth. Nothing animate or organic could endure his burning rays, if they shone continuously or vertically upon one point, or could exist without their occasional presence. Hence the provision for a diurnal rotation, to prevent the exposure of any portion of the globe to the action of those rays for twenty-four consecutive hours, except for a limited period, and at a considerable angle, in the polar regions. But the earth is spheroidal, and a diurnal revolution would still leave that portion which lies under the equator too much, and the other too little, exposed to the action of the sun. This is obviated by an annual revolution of the earth around the sun, and an obliquity of its axis, by reason of which the northeru and southern portions are alternately and, as far as the tropics vertically, exposed to the sun; and it is made to travel from tropic to tropic, producing summer and winter, and other important phenomena.