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ingly restricted to certain localities, which are favourable to their growth, and are hence considered rare plants. Thus, for example, there are certain species which require that the air surrounding them should contain a minute quantity of salt, dissolved in its moisture;-these only abound, therefore, near the seashore; but they are seen to spring up in the neighbourhood of salt-works, even many hundred miles inland,—their seeds being conveyed by the wind or by birds, which have spread them over the whole surface of the earth, but there only meeting with the conditions they require for their development. On the other hand, there are many which can grow in almost any situation, and which can adapt themselves to a great variety of circumstances, often exhibiting evident changes of form and aspect, which are due to the influence of these. Such are common plants; and many of them are among those most serviceable to man, on account of the improvement which can be effected in them by cultivation. For example, the Potatoe, growing in its native climate-the tropical portion of South America,-does not require for the growth of its young shoots that store of nourishment which, in temperate climates, is provided in its fleshy tubers; and the edible portion is thus extremely small, since the warmth and moisture constantly supplied to it develope the growing parts without such assistance. But when transplanted to colder regions, and to a richer soil, that store is greatly increased in amount, and becomes one of the most important of all articles of food to man. If it were not for this capability of adapting itself to new circumstances, the plant could not thrive in Northern Europe; since its own powers of growth would be insufficient, when the external conditions are so much changed. But it is this very capability which renders it so useful to man. If the large Potatoes of European cultivation be planted again in tropical climates, the produce is little superior to that of the original stock; since, when circumstances no longer demand it, the ac

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quired habit ceases. The Cabbage, Broccoli, Cauliflower, &c., are, in like manner, only varieties of one species, greatly altered by cultivation; the plant which was the original stock of all having been formed susceptible of more remarkable changes than most others, and thus rendered at the same time useful to man, and very easy of production.

These instances, to which many more will be hereafter added, will suffice to show that it is not only in their original state that the adaptation of each tribe of plants to particular circumstances is exhibited; since there are many which can thus spread themselves, or may be spread by man, over a large part of the globe. And in this capability, no less than in their original aspect, do we recognise the wisdom and power of the Almighty Designer, who willed that no portion of the globe should be unclothed by vegetation, and that from every part the herbage should spring forth for the supply of the Animal creation, which is entirely dependent on it, either directly or indirectly, for its sustenance.

Such, then, being the universal diffusion of these beings, it is obvious that in no spot can he who seeks to make himself acquainted with their structure and habits, be without some subjects for examination. And since the humblest and simplest plants are found, when examined, to display an organization as remarkably and beautifully adapted to the functions they are to perform, and to the conditions in which they are to exist, as is that of the highest and most complicated, there is no reason why any should be neglected, however insignificant they may appear.

The following volume is intended to serve as a guide to those who are inclined to make the wonders of the Vegetable kingdom an object of their regard, either as a source of recreation, or with those higher views to which the student of Natural History can scarcely avoid being led. For although no doubt can be entertained by the reflecting mind that the Power, Wisdom, and Goodness of the Creator are everywhere operating with equal energy,

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whether in the simple but majestic arrangement of the heavenly bodies, or in those changes by which our own globe is rendered fit for the habitation of such innumerable multitudes of living beings, no one can help feeling that it is in the structure and actions of these beings themselves, that these attributes are more evidently manifested to the intelligent observer. And although the Animal kingdom has usually been regarded as affording more remarkable instances of their display than the Vegetable world, it may be doubted whether, when the latter is more closely examined, it will not appear equally or yet more wonderful.

CHAPTER I.

OF THE GENERAL CHARACTERS OF LIVING BEINGS, AND THE DISTINCTION BETWEEN ANIMALS AND VEGETABLES.

1. When we examine any common Vegetable, we find that it is composed of a number of parts, differing in their form and structure, such, for example, as the stem, roots, leaves, and flowers. Each of these we might again subdivide into others;the leaves, for example, into the footstalk on which they are supported, and the expanded portion or blade. The blade of the leaf may be again distinguished into the midrib and the branching veins proceeding from it (which form as it were its skeleton), and the soft fleshy portion which clothes these ; and we might further convince ourselves, by a little examination, of the presence of a kind of skin or cuticle, which envelopes the whole. Now these several parts of the structure of a plant, which have their respective uses in maintaining its life,-the roots, for example, being to suck up moisture from the soil through which they spread themselves, and to fix the whole structure in the ground,—the stem to convey this to the leaves, which it elevates into the air, and exposes to light and warmth,-the leaves to convert or elaborate this crude fluid into nutritious sap,-and the flowers to produce seed by which the being propagates its race,--these several parts are termed the organs of which the plant is composed; and the uses of these parts-the changes they perform-are called their functions.

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2. Now it is in the presence of these different organs of the chief distinctions exists, between those structures which possess or have ever possessed life, and dead inert matter. In the stone or the mass of metal, we perceive that every part is similar to

GENERAL CHARACTERS OF LIVING BEINGS.

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every other part; it has the same structure, the same properties. If it possesses the crystalline form, it may be reduced into an almost indefinite number of smaller crystals similar to itself; and as to its properties, the chemist cares not (except as a matter of convenience) whether he examines a single grain or a mass of a ton weight. Nay, of many substances, the properties are so peculiar that they can be recognised with certainty in quantities so minute as to be scarcely visible; thus, arsenic, when administered as a poison, has been detected after death in a quantity probably less than the hundredth of a grain; and yet the experienced chemist has no hesitation in asserting that this minute crystalline metallic substance is arsenic, because he recognises in it the same form and the same properties which a larger mass of that substance would exhibit.

3. Far different is it with regard to a Plant or Animal. These may be divided and subdivided; but they then entirely lose their original character, for the parts or organs no longer bear any resemblance to the whole or to each other, either in form, structure, or properties. Thus, then, we see that the bodies which are formed to exhibit those actions to which we give the general term of Life, are peculiarly distinguished from dead matter by the presence in them of a number of parts or organs, distinct alike in their form, structure, and properties; hence such are called organized bodies. On the other hand, dead inert matter may be divided with any degree of minuteness into parts similar to each other in form, structure, and properties; hence it is termed inorganic, or destitute of organs.

4. There is another peculiarity possessed by living beings in regard to their actions or functions. Some of these actions are governed by the same laws as those which operate on inorganic matter; the blood is propelled by the heart of an animal, for example, through its system of branching vessels, just upon the same principle that a forcing-pump drives water through the pipes which convey it over a large city. But the nature of the force is quite different. In the latter case it is merely mechanical. In the former it results from a property peculiar to organized structure,

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