known Seed, contrary to that false opinion of men prejudiced to the contrary, who believe they are Pro∣duced out of putrifying Clay and Water; as if such a chance-Productor had the power to produce a Creature in all Ages to be admired, and hardly by the most In∣genious and Wise to be described.
This Ephemeron is a Four-winged creature, fur∣nished with Two small Horns, Six Legs, Two very long and straight hairy Tails, and living at longest in this shape or form but Five Hours; is found yearly in all the mouths or entrances of the Rhine, as the Maes, the Wael, the Leck, and the Isel; about Mid-summer flying on the Surface of the water for Three dayes succeeding; but with this difference, that those which have lived and flown the First day, die the same Evening; and the same happens the Second and Third day, and then ceaseth till next Year and Season when the like happens again.
At the same time the Female Ephemeron being risen out of the water, and in the rising, having shed her Skin, and having for some time flown, and as it were sported above the Surface of the water, she shoot∣eth her double Egg cluster, or Ovarium in the water; after which the Male also being risen out of the water, and as before in the rising having shed his skin, and afterwards on Land stript another thin Film, also shooteth his Seed on the Female Seed, and thereby fructifieth it. But how properly this Genera∣tion is effected, and how these Insects rise out of the water, and how in the water and on the land they shed their Skins, shall be in this following relation more largely and circumstantially described.
This very wonderful flight of this Insect, living in this form and shape but Five Hours, I have for the first time seen in a Branch of the Rhine, running by Cui∣lenborch in the Year 1667. I find also in Clutius, who hath writ of these Insects, that they are also found at Arnhem, Zutphen, at the Cut by Vtrecht, at Rot∣terdam,