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THE GENERAL SUBJECT.
Why are certain animals called Mammalia or Mammifera?
Because they have breasts (mamma) with which the females suckle their young.
Why is the class of mammifera placed at the head of the animal kingdom?
Because, not only that we ourselves belong to it, but it is that class which possesses the most numerous faculties, the most delicate sensations, and the greatest variety of action; and in which the assemblage of all these qualities appears so combined, as to produce an intelligence more perfect, more fertile in resources, less the slave of instinct, and more capable of progressive perfection, than what is found in any of the other classes.
Why are mammalia and birds called warm-blooded? Because their blood is of heat about 100°, more or less.
Why are other animals called viviparous ?
Because they produce their young alive and perfect, (from vivus and pario) as man, quadrupeds, &c.
Why are certain animals called vertebrated?
Because they have a cranium, or bony cavity, containing the brain, and a succession of bones called the spine, and the divisions of it vertebræ, proceeding from the cranium, and containing a prolongation of the brain, denominated the spinal marrow. Why are other animals called invertebrated? Because they have no vertebræ.
Why does the faculty of instinct differ from intelligence?
Because instinct makes animals perform certain actions, necessary to the preservation of the species, but often altogether foreign to the apparent wants of the individual; and often, also, extremely complicated. We cannot attribute these actions to intelligence, without supposing a degree of foresight and understanding infinitely superior to what we can admit in the species that perform them. The actions performed by instinct are not the effects of imitation, for the individuals that execute them, have often never seen them done by others; they bear no proportion to the common intelligence of the species, but become more singular, more skilful, more disinterested, in proportion as the animals belong to the less elevated classes, and are, in other respects, most stupid. They are so much the property of the species, that all the individuals perform them in the same manner, without any improvement.
The working bees have, since the beginning of the world, constructed the most ingenious edifices, agreeable to principles of the highest geometry, and destined to lodge and nourish a posterity which is not even their own. Solitary bees and wasps form also very complicated nests for their eggs. From the egg there springs out a worm, which has never seen its mother, which does not know the structure of the prison in which it is enclosed; but, when once it is changed into a wasp or bee, it constructs a similar nest, equally perfect, for its own egg.
Why is fossil osteology, or the knowledge of bones dug out of the earth, an important branch of anatomy?
Because it not only brings to our knowledge races of animals, very different from those with which we are acquainted, but supplies many intermediate links, in the gradation of structure, which are wanting in the present creation ; and, therefore, makes it probable that, when the two are sufficiently investigated, one regular, connected chain will be formed, each class of animals imperceptibly running into that which is next to it. Sir E. Home.
Why are bones excellent manure ?
Because of the large proportion of lime which they contain.
Why are teeth important in identifying different
Because, by the largeness of the tooth, the naturalist can judge of the relative size of the animal which bore it; and by the form of the tooth he can tell whether it was fitted to grind grass, or to tear flesh; and therefore, whether it belonged to an herbivorous or a carnivorous species. Pursuing his enquiries from this point, he could decide in a great degree, as to the structure of the stomach and viscera; the extremities, whether armed with claws or protected with hoofs; and, farther, he can judge of the vivacity of the senses which belonged to the animal, and of the habits which it derived from its peculiar conformation:-knowing, beyond all doubt, that there was an intimate agreement in all the properties of its existence, and that every thing in its organization was regulated by an undeviating harmony. - Lib. Ent. Knowledge.
Why are the lives of wild animals shortened by the loss of teeth?
Because, as old age increases, the teeth fall out, 1*