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Vermes and Zoophytes. Tentac'ula, often called feelers; organs supplying the place of hands and arms to some animals, and intended also for feeling.
(Singular, Tentaculum.) The term Ver'mes has been used with great vagueness in natural history, and employed to designate animals to which the name was not appropriate. It is now, however, more restricted in its application, and is made to include only a small class of animals. Their bodies are of a cylindrical, elongated shapé, divided into a great number of rings. In some species, certain black points appear around the head, which have been supposed to be eyes, but this is doubtful. They are the only invertebral animals which have red blood. It circulates in a double system of vessels, but there is no distinct fleshy heart to give it motion. They breathe by means of gills, which are sometimes within and sometimes without their bodies. They have no limbs, but on each of the rings of which their bodies are composed, are little spines or bristly projections which answer in some sort the
All, except the earthworm, inhabit the water. Many of them bury themselves in the sand; some form themselves a sort of tube or habitation of sand, or other materials, and others exude from their surfaces a calcareous matter, ' which produces a shell around them. When cut through the middle, each portion becomes a distinct individual.
There are several species of the leech, of which the medicinal leech is the most valuable. It has three jaws or rather lancets, with which it pierces the skin of animals, in order to draw their blood. Its tail is furnished with a shallow cup, by which it is able to fix itself firmly to different objects, while obtaining its nourishment; and by means of the same organ it moves from place to place.
The class of Zo'ophytes is the last division of the animal kingdom, and the lowest in the scale of the animated creation. It includes an immense number of individuals but imperfectly known, and having but few points of resemblance and connexion with one another. In general, they have no nervous system, no complete vascular circulation,
purpose of feet.
no distinct apparatus for respiration, and no sense but that of feeling and perhaps that of tasting. This is not true however, without exception; for, in some instances, traces of a nervous system, of a circulation, and of respiratory organs, may be detected, as in the sea-urchin, the common star-fish, and the sea-egg. These Zoophytes are the most perfect in their structure, and are endowed with a curious set of organs for the purpose of motion. Their shells are pierced with a large number of holes, regularly arranged, through which project the feet of the animal, or rather the instruments answering the purpose of feet. These are little hollow cylinders, filled with a liquid, and terminating in a kind of knob, which is also hollow. By forcing the liquid into these cylinders, or by exhausting it from them, the animal can either lengthen or shortan them. The knob, when exhausted, is drawn into a cup-like form, and thus may be firmly fixed to whatever object it is applied, like a cuppingglass; and when the liquid is again thrown into it, it is again loosened.
Pol'ypes have a hollow, cylindrical, or conical body, with one extremity open which serves for their mouth, and is surFounded by a number of organs, (tentacula) by which they seize their prey. Many of them have been celebrated on account of the fact, that when one is divided into several pieces, each piece becomes a distinct animal, perfect in all its parts. The immense beds of coral and the different kinds of sponge, are nothing but the habitations of infinite numbers of these little animals, and are produced by their labour. Corals grow in such quantities, and to such heights in some seas, as to create islands. The Friendly Islands, in the Pacific Ocean, were thus raised by corals from the depth of that sea. Ships have often been lost by striking on coral-rocks.
QUESTIONS.--1. What is said of the former and present application of the term Vermes? 2. What is said of the structure of Vermes ? 3. Of the circulation of their blood and of their respiration? 4. Of their instruments of motion, and their habitations ? 5, Describe the medici. nal Leech. 6. What is said of the general structure of Zoophytes ? 7. Describe the organs of motion in the most perfect Zoophytes. 8. What is the structure of Polypes ? 9. For what celebrated ?" 10. How are corals and sponge produced ?:11. What is said of the growth of corals in some seas? (Note. To the class of Zoophytes belong In. testinal worms, sea-nettles, or sea-anem'ones, Medusæ, or sunfish, and
EXISTENCE OF THE DEITY.
Animalcules, which have been called infusorial animals, (Infusoria,) because they are principally found in some animal and vegetable fluids and infusions.) 12. What are the orders of Vermes according to Linnæus ? (see Appendix.) 13. In treating of a particular animal, how are naturalists accustomed to designate it? 14. Give examples.
Existence of the Deity. God and the r:orld which he has formed are our great objects. Every ining which we strive to place between these is nothing. We see the universe, and seeing it, we believe in its Maker. The universe exhibits indisputable marks of design: it is not, therefore, self-existing, but the work of a designing mind. From the great masses that roll through space, to the slightest atom that forms one of their imperceptible elements, every thing is conspiring for some purpose. I shall not speak of the relations of the planetary motions to each other,---of the mutual relations of the various parts of our globe, -of the different animals of the different elements, in the conformity of their structure to the qualities of the elements which they inhabit,-of man himself in all the nice adaptation of his organs :—to these splendid proofs, it is scarcely necessary to do more than to allude. But when we think of the feeblest and most insignificant of living things,-the minutest insect which it requires a microscope to discover, when we think of it as a creature, having limbs that move it from place to place,-nourished by little vessels, that bear to every fibre of its frame, some portion of the food which other organs have rendered fit for serving the purposes of nutrition ;-having senses, as quick to discern the objects that bear to it any relative magnitude as ours, – and not merely existing as a living piece of most beautiful mechanism, but having the power, which no mere mechanism, however beautiful, ever had, of multiplying its own existence, by the production of living machines exactly resembling itself ;-when we think of all the proofs of contrivance which are thus to be found in what seems to us a single atom, or less than a single atom, and when we think f the myriads and myriads of such atoms, which inhabit n the smallest portion of that earth, which is itself but
almost an invisible atom, compared with the great system of the heavens, --what a combination of simplicity and grandeur do we perceive! It is one universal design, or an infinity of design ;--nothing seems to us little, because nothing is so little as not to proclaim the omnipotence which made it ;—and I may say too that nothing seenis to us great in itself, because its very grandeur speaks to us of that immensity, before which all created greatness is scarcely to be perceived.
On particular arguments of this kind, however, that are as innumerable as the things which exist, it is not necessary to dwell. Those whom a single organized being, or even a single organ, such as the eye, the ear, the hand, does not convince of the being of a God,—who do not see him, not more in the social order of human society, than in a single instinct of animals, producing unconsciously, a result that is necessary for their continued existence, and yet a result which they cannot have foreknown—will not see him in all the innumerable instances that might be crowded together by philosophers and theologians.
The world, then, was made ;--there is a designing Power which formed it--a Power whose own admirable nature explains whatever is admirable on earth, and leaves to us instead of the wonder of ignorance, that wonder of knowledge and veneration which is not astonishment, but love and awe.
Political Economy. Tech'nical, belonging to arts; not in common or popular use. The language of science is frequently its most difficult part, but in political economy there are few technical terms, and those easily comprehended. It may be defined as the science which teaches us to investigate the causes of the wealth and prosperity of nations.
In a country of savages, you find a small number of inhabitants spread over a vast tract of land. Depending on the precarious subsistence afforded by fishing and hunting, they are frequently subject to dearths and famines, which cut
them off in great numbers. As soon as they begin to apply themselves to pasturage, their means of subsistence are brought within narrower limits, requiring only that degree of wandering necessary to provide fresh pasturage for their cattle. Their flocks ensuring them a more easy subsistence, their families begin to increase; they lose in a great measure their ferocity, and a considerable improvement takes place in their character.
By degrees the art of tillage is discovered, a small tract of ground becomes capable of feeding a greater relative number of people; the necessity of wandering in search of food is superseded; families begin to settle in fixed habitations; and the arts of social life are introduced and cultivated.
In the savage state scarcely any form of government is established; the people seem to be under no control but that of their military chiefs in time of warfare. The possession of Aocks and herds in the pastoral state introduces property, and laws are necessary for its security; the elders and leaders therefore of these wandering tribes begin to establish laws, to violate which is to commit a crime and to incur a punishment. This is the origin of social order; and when in the third state the people settle in 'fixed habitations, the laws gradually assume the more regular form of a monarchical or republican government. Every thing now wears a new aspect; industry flourishes, the arts are invented, the use of metals is discovered ; labour is subdivided; every one applies himself more particularly to a distinct employment, in which he becomes skilful. Thus, by slow degrees, this people of savages, whose origin was so rude and miserable, be come a civilized people, who occupy a highly cultivated country, crossed by fine roads, leading to wealthy and populous cities, and carrying on an extensive trade with other countries.
The whole business of political economy is to study the causes which have thus co-operated to enrich and civilize a nation. This science, therefore, is essentially founded upon history,--not the history of sovereigns, of wars, and of intrigues, but the history of the arts, and of trade, of discoveries, and of civilization. We see some countries, like America, increase rapidly in wealth and prosperity, whilst others, like Egypt and Syria, are impoverished, depopulated, and falling to decay; when the causes which produce these va