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In the orders of animals next to man, we find the senses of sight, touch, taste and smell equally perfect as those possessed by him, and in some cases, they are even more acute ; but as we proceed downwards through the gradations of animal exist. ence, we perceive the number and acuteness of the senses to diminish-we find some beings with but four senses, some with three, others with two, and lastly, in the Zoophites, we find only the sense of touch, and that so faintly exhibited as almost to lead us to doubt its existence.
Let us, after these observations, return to the distinction between animals and vegetables. You now perceive that although you would find no difficulty with regard to a nightingale and a rose, to discover to which of the kingdoms of nature they belong ; yet with respect to a sponge or coral, and a mushroom or a lichen, it would be somewhat difficult, without a previous knowledge of their classification, to say which is called animal, and which vegetable, or to give the distinctions between them. We have seen among the zoophites, that the polypus may be increased by cutting shoots and engrafting them upon other animals, in the same manner as vegetables may be increased.
With respect to sensation, some plants discover this, apparently even in a greater degree than some of the last orders of animals; the sensitive plant shrinks from the touch ; the Dio. nea suddenly closes its leaves upon the insect which touches them ; the leaves of plants follow the direction of light, in order to present their upper surfaces to its influence; this you can observe in flower pots placed by a window. The seed of a plant, in whatever situation it may be placed in the earth, always sends its root downwards, and its stem upwards; in these cases, does there not seem as much appearance
of sensa. tion and instinct, and even more than in the lower orders of animals ?
We find then, that the possession, or want of instinct, does not constitute a mark of distinction between animals and plants.
Some have attempted to draw a line of distinction, by considering, that locomotion, or the power of changing place, belongs to animals only; but this criterion seems to fail, since we find animals fixed to the bottom of the sea, or growing upon rocks, and plants moving upon the surface of the water.
Another mark of distinction has been given, in the supposed presence of nitrogen in animals, detected by a peculiar odour
Senses of the orders of animals inferior to man--Sensation seems to be possessed by some plants-Instinct not peculiar to animals--Locomotion Nitrogen.
when animal substances are burning, similar to what we per. ceive in the combustion of bones; but nitrogen having been discovered in some vegetables, this proof is no longer considered infallible.
It appears then from a comparison between animals and vegetables, that these beings are closely connected by the essential characters of organization; that it seems impossible to distinguish them by any trait that belongs exclusively to either; that the connexion between them appears the most striking in the least perfect species of both kingdoms; and that as we recede from this point, the differences become more numerous and more marked.
We may illustrate this view, by imagining two ascending chains, rising from one common point, each side of the chain becoming more and more unlike in proportion to the interven. ing distance from the centre. From this same central point, also proceeds the chain of inorganized substances; some imperfect animals resembling plants in their outward form, some, both of animals and plants, resembling minerals in their hard and calcareous coverings and shapeless forms.
Having thus learned the almost imperceptible gradations, by which the animal and vegetable kingdoms are blended, we must, in stating the important differences which exist between animals and plants, consider the imperfect species of both kinds, as exceptions to any general rule, and confine ourselves to perfect animals and plants.
1st. Plants differ from animals with respect to the elements which compose them ; carbon, hydrogen and oxygen, form the base of vegetable substances; animals exhibit the same elements with this important distinction, that carbon prevails in plants, and nitrogen in animals.
2d. They differ in their food ; plants are nourished with inorganized matter, absorbed with water, the various substances which this liquid holds in solution ; animals are mostly nourished either by vegetables or other animals.
3d. Plants throw off oxygen gas, and inhale carbonic acid ; animals in respiration inhale oxygen gas, and throw off carbonic acid.
4th. Although plants and animals both possess a principle of life, it is in the one case much more limited than in the other ; exhibiting itself in plants by a feeble power of contraction or irritability ; in animals appearing in sensation, muscular movement and voluntary motion.
We see then, many important differences between perfect
Result of the comparison between animals and vegetables-Chains of beings proceeding from one point-Differences between animals and plants.
animals and perfect plants. We have, in numerous instances, pointed out striking analogies between the two great divisions of organized bodies; this subject might be greatly enlarged, but every human effort has its limitation ; and we have already, amid the multitude of interesting facts and reflections presented by the vegetable creation, far exceeded the bounds originally prescribed. A few remarks upon the inorganized matter connected with our globe, must close our present course.
Inorganic bodies form the solid base of the globe. Minerals are spread upon the face of the earth or lie buried beneath its surface. They form vast masses of rocks, chains of mountains, and the ground upon which we tread. The Water occupies a still greater surface of the earth than the land; it is filled with life and animation; the treasures and wonders of the deep seem almost unbounded. The Air, lighter than earth and water, extending on all sides about forty miles in height, surrounds the whole globe, separating us from the un. known elements which exist beyond it. Among the inorgani. zed substances upon our globe, is Heat or Caloric, a subtle fluid which pervades all matter, in an increasing proportion from solids to fluids, and from fluids to gases; and Light, which reflects its hues from terrestrial objects, producing by the de. composition of its rays, all the beautiful variety of colouring. The laws which govern these two substances, so extended in their existence, and so various in their operations, are explain. ed in the sciences of Chemistry and Optics.
Wherever we turn our eyes, we behold wonders ; “ if we go up to Heaven, God is there ;" “ the firmament showeth forth his handy work ;” if we contemplate the earth on which we are placed, and all its varied tribes of beings, with the in. organized substances formed for their comfort and subsistence, we realize, that “ even the hairs of our head are all number. ed,” and that it is indeed God, “ who maketh the grass to grow upon the mountains, and herbs for the use of man.”
Different kinds of inorganic matter—The Deity manifested in his work.
The Universe, how vast! exceeding far,
Turn, child of ignorance and narrow views,
, and with care preserved ? Who teaches, when this principle of life Thus animated, swells the germ within, And bursts its tomb, rising to light and air; Who teaches root and stem to find their place, Each one to seek its proper element ?
Who gilds the insect's wings and learls it forth To feast on sweets, and bask in sunny ray ? None could the life of plant or insect give; Save God alone, He rules and watches all ; Scorns not the least of all His works; much less Man, made in his image, destin’d to exist, When e'en yon brilliant worlds shall Then how should man rejoicing in his God, Delight in His perfections, shadow'd forth In every little flow'r, and blade of grass ! Each opening bud, and care perfected seed, Is as a page, where we may read of God.
ease to be.
THE following description of genera and species is intended to furnish exercises for the student in practical botany. It is designed to include the most common indigenous and exotic plants; such as teachers can most readily procure for their classes, and such as pupils are most likely to meet with in their botanical excursions. Those who expect to go beyond the elements of the science, will find in the Manual of Profes. sor Eaton a complete list of American plants.
Botanical Districts. Eaton considers North America as divided into two botanical districts, northern and southern. The dividing line to be drawn from the mouth of Delaware river (N. Lat. 39°, W. Lon. 75°), to the south end of Lake Michigan (N. Lat. 41° 31'); leaving in the northern district all Pennsylvania, and the north part of Delaware, Maryland and Ohio. The division line thus rises as we go towards the west, because southern plants ex. tend to higher latitudes on the western side of the Allegany range, than on the eastern side.
The northern district is divided into eastern and western, by a line drawn from the intersection of the Allegany range and the Potomac river, in the direction of Cayuga lake. The Allegany mountain is the dividing line in the southern district. Explanation of figures, letters and characters, used in the Generic and Specific descriptions,
Numbers. The first number following the generic description, is the number of the natural order of Linnæus, the second number is that of Jussieu.
Letters. E and W are used to denote that the plant is found in the eastern or western division of either of the districts.
S, at the end of a description, shows that the plant grows in the southern as well as northern district.