To form a just idea of the ovaries of insects, I could wish the reader to consult the description that Swammerdam has given of that of the queen bee, and to take a view of the elegant figure that accompanies it, a figure that speaks to the eyes, and by them to the imagination. Malpighi has given a description of the ovaries of the silk-worm moth.
Reaumur mentions six or seven species of two-winged flies that are viviparous, bringing forth worms, which are afterwards transformed into flies. The womb of one of these is singularly curious; it is formed of a band rolled up in a spiral form, and about two inches and an half in length; so that it is seven or eight times longer than the body of the fly, and composed of worms placed one on the side of the other with wonderful art: they are many thousands in number.[81]
[81] Reaumur Mem. des Insectes, tom. 4, p. 415.
These are a species of insects that have opened new views of the œconomy of animated beings; they belong to the hemiptera class. The rostrum is inflected, the antennæ are longer than the thorax; some have four erect wings, others are entirety without them. Towards the end of the abdomen there are two tubes ejecting that most delicate juice called honey-dew. Various names have been applied to them, the proper one is aphis, that by which they are most generally known, is puceron; they are also frequently called vine-fretters or plant-lice: many among the genera are both oviparous and viviparous, bringing forth their young alive in summer, but in autumn depositing their eggs upon the branches and bark of trees. The different aphides are very curious objects for the microscope: they are a very numerous genus, Linnæus has enumerated thirty-three different species, whose trivial names are taken from the plant which they inhabit, though it is probable the number is much larger, as the same plant is often found to support two or three different sorts of them. Their habits are very singular: an aphis or puceron, brought up in the most perfect solitude from the very moment of its birth, in a few days will be found in the midst of a numerous family; repeat the experiment on one of the individuals of this family, and you will find this second generation will multiply like its parent; and this you may pursue through many generations.