OF THE GENERATION OF ANIMALS, HOW ANIMALS ARE BEGOTTEN, AND WHETHER THEY ARE OBNOXIOUS TO CORRUPTION. Those philosophers who entertain the opinion that the world had an original do likewise assert that all animals are generated and corruptible. The followers of Epicurus, who gives an eternity to the world, affirm the generation of animals ariseth from the various permutation of parts mutually among themselves, for they are parts of this world. With them Anaxagoras and Euripides concur: For nothing dies, But different changes give their various forms. Anaximander’s opinion is, that the first animals were generated in moisture, and were enclosed in bark on which thorns grew; but in process of time they came upon dry land, and this thorny bark with which they were covered being broken, they lived for a short space of time. Empedocles says, that the first generation of animals and plants was by no means completed, for the parts were disjoined and would not admit of a union; the second preparation for their being generated was when their parts were united and appeared in the form of images; the third preparation for generation was when their parts mutually amongst themselves gave a being to one another; the fourth, when there was no longer a mixture of similar elements (like earth and water), but a union of animals among themselves,—in some the nourishment being made dense, in others female beauty provoking a lust of spermatic motion. All sorts of animals are discriminated by their proper temperament and constitution; some are carried by a proper appetite and inclination to water; some, which partake of a more fiery quality, to breathe in the air; those that are heavier incline to the earth; but those animals whose parts are of a just and equal temperament are fitted equally for all places. CHAPTER XX. HOW MANY SPECIES OF ANIMALS THERE ARE, AND WHETHER ALL ANIMALS HAVE THE ENDOWMENTS OF SENSE AND REASON.