although the heat is greater, the humidity is less constant. China and part of the United States of America, are exceptions, for in them a happy mixture of climates produces a luxuriant and beautiful vegetation. In those favoured regions, "where," as an enthusiastic admirer of nature says, "the great magnolia shoots up its majestic trunk, covered with evergreen leaves, and decorated with a thousand beautiful flowers, that perfume the air around; where the forests and fields are adorned with blossoms of every hue; where the golden orange ornaments the gardens and groves; where bignonias of various kinds interlace their climbing stems around the white-flowered stuartia, and mounting still higher, cover the summits of the lofty trees around, accompanied with innumerable vines, that here and there festoon the dense foliage of the magnificent woods, lending to the vernal breeze a slight portion of the perfume of their clustered flowers; where a genial warmth seldom forsakes the atmosphere; where berries and fruits of all descriptions are met with at every step:"-In those regions, man finds the fewest impediments in extending his race; for, in their natural state, the forests afford an abundant supply of animal and vegetable aliment, and under cultivation, the fields and orchards are loaded with grain and fruits of species which occur in the tropical and northern zones.

But it is in the torrid zone that nature displays all her magnificence. There the species of tribes which in other climates are herbaceous, become shrubs, and the shrubs trees. Ferns rise into trunks equal to those of the northern regions of Europe, balsams, gums and resins exude from the trees; aromatic fruits and flowers abound, and the savage, as he roams the woods, satisfies his hunger with the spontaneous products of the soil. Here also are all the climates of the globe, and almost all their productions united; for, while the plains are covered with the gorgeous vegetation of the tropics, the lofty mountains display the forms that occur in the colder regions, and the places intermediate in elevation, all the graduated transitions from these to the warmest latitudes. It were vain to attempt the description of these scenes, which have been depicted by Humboldt in tints directly transferred from the originals.

The vegetation of the seas presents infinitely less diversity than that of the land. It is less luxuriant, less elegant, less ornamented, and less productive of substances directly useful to man. There is also less difference of aspect between marine plants of different latitudes, for the great currents of the ocean and other causes render its temperature more equable than that of the atmosphere.

In the reproduction, growth, and maturation of plants, phenomena are presented to us, which are well calculated to elicit our admiration; but the exposition of the mechanism and processes by which they are effected, in so far as they are known, is inconsistent with the objects here in view. Suffice it to say, that by a curious and diversified apparatus of tubes and cells, in which are circulated fluids derived from the atmosphere and the earth, the more perfect plants perform all their intended functions. In animals, we can trace the various organs by which extraneous matter is assimilated and applied to the development of parts; but, in plants, which are apparently more simple in their organization, the microscope, aided by chemical analysis, fails to detect the minuter mechanism. We know that plants absorb and give out various gases, that their juices perform various motions, that various products are formed in them, and that they contain certain principles; but the peculiar means by which these phenomena are produced are still exceedingly ob

scure.

Botanists reduce plants to a few primary divisions or classes. Some, the most simple in their organization, are composed of aggregated cells, such as mosses and lichens, and are termed Cryptogamic or cellular plants. Others, as ferns, have tubes or vessels mingled with their cellular texture, but do not produce flowers. Of the plants furnished with these organs, and named Phenogamous, some have a uniform structure of cells and tubes throughout their whole transverse section, and are called Monocotyledonous vegetables; while others, the Dicotyledonous, have a different arrangement of their elementary organs, and in a transverse section present concentric circles, denoting the existence of cylinders placed within each other. These different kinds occur together in all the regions of the globe; but the fact

which it is my object here to impress, is that there is, a kind of gradation in plants from those of simple to those of complex

structure.

Remains of vegetables are of frequent occurrence in almost all the stratified rocks, from the lowest secondary up to the highest diluvial; and the characters which these remains still retain, enable us to form some idea of the nature of the vegetation which existed at the remote periods preceding their immersion in the strata. The lowest secondary formations are poor in vegetable remains, and those which have been observed in them have been referred to the most simply organized tribes. The coal formation abounds in plants. Coal itself is in factnothing else than a mass of decayed vegetables, altered by various circumstances. The plants observed in this deposit are also of the lower orders, but many of them have gigantic dimensions, and resemble those which grow at present in tropical countries. These gigantic plants occur in the coal deposits of all climates, and in general the fossil plants of cold countries are not inferior in size to those of the warmer regions, so that if they have been deposited near the places where they grew, the ancient vegetation of the globe has been more equable than the present. The remains found in the coal formation all belong to land plants, whereas in certain other deposits marine species are observed. This difference indicates, that while some deposits have been formed on the land or in fresh water, others have been formed under the sea. In the strata between the coal and chalk formations, the plants of inferior organization still predominate; but above the chalk the numerous species which occur are generally of higher orders, and approximate besides, in their generic and specific forms, to the species which are at present dispersed over the globe.

ON COOKING FOOD FOR HORSES. By Mr WILLIAM DICK, Veterinary Surgeon, Edinburgh.

THE deficiency in last year's crop of hay and straw was such as to have been severely felt by all those connected with horses, and naturally excited a desire of using these articles as economically as possible; and as the attention which has been bestowed by some individuals who have had a pretty ample field for experiment, has led to what I consider some useful results, it appears to me, that, notwithstanding the very favourable prospects which is before us in every part of the country, the knowledge that much saving may be effected by an economical use of fodder, may be useful to all or most of your agricultural readers. And, even should the abundance of the present crop be such as to render it a matter of less moment now than it would have

been last season, and may be on some future occasion, still the

knowledge of the fact is at least worth recording; and that fact is, that a horse may be kept upon a much less quantity of hay than is generally supposed to be necessary for him, and that without stinting him of a proper allowance of that kind of provender. Horses, when allowed as much hay as they commonly are, almost invariably waste a considerable quantity of what is placed before them; the wasted portion with them goes for nothing, but it costs the full price to the owner of the animal. This waste, on an average, amounts to nearly one-half, or at least onethird, of what is consumed. It is quite evident, therefore, that, if the portion that is wasted could be saved, a great diminution in the expense of keep would be the result. A saving, however, is not only to be effected by avoiding waste, as far as that is possible, but another saving may be effected by the means employed to effect the other, which I shall now endeavour to explain.

Before either vegetable or animal food is in a proper state to be acted on by the stomach and other organs immediately concerned in the digestive process, it is necessary that the food which is to pass into the stomach should be broken down, and minutely comminuted. This is more especially the case in regard to herbivorous animals: hence we see that these animals

have first a mill, the grinding teeth, by which it is reduced to a kind of coarse powder; it is at the same time mixed with a large quantity of fluid, the saliva, the quantity of which is almost incredible to those who have not had an opportunity of ascertaining it, but which the following fact will testify. A black horse had received a wound in the parotid duct, which became fistulous. When his jaws were in motion, in the act of eating hay, I had the curiosity to collect in a glass measure the quantity which flowed during one minute, by a stop-watch, and it amounted to nearly a dram more than two ounces in that time. Now, if we calculate that the parotid gland, on the opposite cheek, poured into the mouth the same quantity in the same time, and allow that the sublingual and submaxillary glands, on each side combined, pour into the mouth a quantity equal to the two parotids, we then have no less than eight ounces of saliva passing into the mouth in one minute, for the purpose of softening the food, and preparing it for digestion. But this is not all: for we find that it requires to be still farther prepared before it passes on to be digested. In the horse we find a portion of the stomach lined by an insensible coat, forming a kind of pouch for the masticated food to steep in, to be prepared to pass on to the portion where the digestion is more especially carried on; and that that is the case we have reason to believe, first, from the circumstance that the coarser portions of the food which are taken into the stomach of the horse are found after death to be lodged in this part of the stomach; and further, that, in other animals, such as the ox and sheep, this process is still more evident. In these animals there is not only the grinding down of the food, and mixing with the saliva, but afterwards it is passed into first one stomach, the paunch, where the food is mixed with the secretions of that viscus, and separated into the coarser and finer portions by a kind of eccentric motion,—which I can compare to nothing better than the motion given to coffee in the newly invented coffee-roaster, or the tossing of corn in a sieve to clean it from dust, the motion certainly not so rapid, but the effect analogous-the finer parts passed into the second stomach, and on to the third, while the coarser, after all this cooking and tossing, is again sent up from the stomach to be still further comminuted, and is thus passed into the third stomach, to undergo farther preparation, before it