1. It has already been observed that the male insects are less than the female, and that the male mounts upon the female; and the manner of their sexual intercourse has been described, and the difficulty of separating them. Most of them produce their young very soon after sexual intercourse. All the kinds except some psychæ (butterflies and moths) produce worms. These produce a hard substance, like the seed of the cnecus,[168] which is fluid within. From the worm an animal is produced, but not from a portion of it, as if it were an ovum, but the whole grows and becomes an articulated animal.
2. Some of them are produced from similar animals, as phalangia and spiders from phalangia and spiders, and attelabi,[169] locusts, and grasshoppers. Others do not originate in animals of the same species, but their production is spontaneous, for some of them spring from the dew which falls upon plants. The origin of these is naturally in the spring, though they often appear in the winter, if fine weather and south winds occur for any length of time. Some originate in rotten mud and dung; and others in the fresh wood of plants or in dry wood; others among the hair of animals, or in their flesh, or excrements, whether ejected, or still existing in the body, as those which are called helminthes.
3. There are three kinds of these, the flat worms, the round worms, and those which are called ascarides. From these creatures nothing is produced; but the broad worm is attached to the intestine, and produces something like the seed of the colocynth, and this is used by physicians as a proof of the presence of the worm.
4. Butterflies are produced from caterpillars; and these originate in the leaves of green plants, especially the rhaphahus, which some persons call crambe. At first they are smaller than millet, afterwards they grow into little worms, in three days they become small caterpillars, afterwards they grow and become motionless, and change their form. In this state the creature is called chrysalis. It has a hard covering, but moves when it is touched. They are united to something by weblike processes, and have no mouth nor any other visible organ. After a short time the covering is burst, and a winged animal escapes, which is called a butterfly.
5. At first, while in the caterpillar state, they take food and evacuate fœces, but in the chrysalis state they do neither. The same is the case with all other creatures which originate in worms, and those which produce worms after sexual intercourse, or even without this process; for the offspring of bees, anthrenæ, and wasps, while they are young worms, consume food and evacuate excrement, but when from worms they receive their conformation they are called nymphæ, and neither feed nor evacuate, but remain quiet in their covering until they are grown. They then make their escape by cutting through a place where the cell is fastened on.
6. The penia[170] and hypera[171] also are produced from a kind of campe (caterpillar) which make a wave as they walk, and as they advance bend the hinder extremity up to that which has preceded. The creature produced always derives its colour from the campe in which it originates. A certain great worm, which has as it were horns, and differs from others, at its first metamorphosis produces a campe, afterwards a bombylius, and lastly a necydalus. It passes through all these forms in six months. From this animal some women unroll and separate the bombycina (cocoons), and afterwards weave them. It is said that this was first woven in the island of Cos by Pamphila, the daughter of Plateos.
7. From the worms in dry wood the insects called carabi are produced in the same manner; for at first they are immoveable worms, and afterwards the carabi are produced by the rupture of their case. The crambides originate in the plant called crambe, and these also have wings, and the prasocurides from the plant called prasum (onion). The œstri are produced from the little flat creatures that are found on the surface of rivers. Wherefore also they congregate in the greatest numbers around the waters where such animals are found. The kind of pygolampis which has no wings originates in a small, black, hairy caterpillar. These undergo another change, and turn into the winged creatures called bostrychi.
8. The empides originate in ascarides, and the ascarides originate in the mud of wells and running waters which flow over an earthy bottom. At first the decaying mud acquires a white colour, which afterwards becomes black, and finally red. When this takes place, very small red creatures are seen growing in it like fuci. At first these move about in a mass, afterwards their connection is ruptured, the creatures called ascarides are borne about in the water, after a few days they stand erect in the water without motion and of a hard texture, and subsequently the case is broken and the empis sits upon it until either the sun or the wind enables it to move, then it flies away.
9. The commencement of life in all other worms, and in all creatures produced from worms, originates in the influence of the sun and wind. The ascarides are produced in greater numbers, and more quickly, where the various matters are mixed together, as in the works conducted in the Megarian territory, for putrefaction thus takes place more readily. The autumnal season also is favourable to their increase, for there is less moisture at that time of the year. The crotones[172] originate in the agrostis, the melolonthæ from the worms which originate in the dung of oxen and asses.
10. The canthari which roll up dung, hide themselves in it during the winter, and produce worms, which afterwards become canthari; and from the worms which inhabit the osprea,[173] winged creatures, like those already mentioned, derive their existence. Flies originate in dung which has been set apart, and those who are employed in this work strive to separate the remainder which is mixed together, for they say that the dung is thus brought to putrefaction.