Go back to Aristotle, and we may listen to him again while he talks of many other kindred insects: of the humble-bee and its kind, of the mason-bee with its hard round nest of clay, of the robber-bees, and of the various wasps and hornets; or (still more curiously and unexpectedly) of the hunter-wasp or 'ichneumon', and how it kills the spider, carries it home to its nest, and lays its eggs in its poor body, that the little wasp-grubs may afterwards be fed. Or again of the great wasps which he calls Anthrenae, and how they chase the big flies, and cut off their heads, and fly away with the rest of the carcass--all agreeing to the very letter with what Henri Fabre tells us of a certain large wasp of Southern Europe, and how it captures the big 'taons' or horse-flies: 'Pour donner le coup de grâce à leurs Taons mal sacrifiés, et se débattants encore entre les pattes du ravisseur, j'ai vu des Bembex mâchonner la tête et le thorax des victimes.' Verily, there is nothing new under the sun. With the metamorphoses of various insects Aristotle was well acquainted. He knew how the house-fly passes its early stages in a dung-hill, and how the grubs of the big horse-flies and Tabanids live in decayed wood; how certain little flies or gnats are engendered (as he calls it) in the slime of vinegar. He relates with great care and accuracy the life-history of the common gnat, from its aquatic larva, the little red 'blood-worm' of our pools; he describes them wriggling about like tiny bits of red weed, in the water of some half-empty well; and he explains, finally, the change by which they become stiff and motionless and hard, until a husk breaks away and the little gnat is seen sitting upon it; and by and by the sun's heat or a puff of wind starts it off, and away it flies.