From the cabbage is engendered the cabbageworm, and from the
leek the prasocuris or leekbane; this creature is also winged. From
the flat animalcule that skims over the surface of rivers comes the
oestrus or gadfly; and this accounts for the fact that gadflies most
abound in the neighbourhood of waters on whose surface these
animalcules are observed. From a certain small, black and hairy
caterpillar comes first a wingless glow-worm; and this creature
again suffers a metamorphosis, and transforms into a winged insect
named the bostrychus (or hair-curl).