Ephemeri vita, or, The natural history and anatomy of the Ephemeron, a fly that lives but five hours written originally in Low-Dutch by Jo. Swammerdam ...
Swammerdam, Jan, 1637-1680., Tyson, Edward, 1650-1708.

CHAP. V.

A Description of the members, or outward parts of the Worm, its Colour, and Nature.

BY a strict examination of the Worm, I find it distin∣guished into Fourteen annular incisures or divi∣sions, whereof the First containeth the Head, the Three following the Breast, and the last Ten the Belly, with its appendant Tails.

In the (a) Head are observable the * Eyes cover∣ed with an entire smooth Film, having on each side its brushy hairs. When the Worm sheddeth its Skin, this Film sheddeth also gradually from the Eyes, which eyes when the worm is fledged appear like a net. Some∣what lower under the eyes appear the two tender and sharp-ending * horns, which are as it were di∣stinguished into several Joints. Next appear the * Toothlike sheres or cheeks which constitute the Beak, at whose beginning underneath appear several other hairy and filmy parts, which have some similitude with those found in Lobsters and Prawns.

At the first ring in the Breast are joyned the * Two foremost legs, in which is observable their shape and their Joints. Their shape is somewhat like those crea∣tures which wroot in the Earth, and therefore these feet have their strongest motion outwards, whereby like Moles they may the better dig away the earth.

Page  12Every Leg hath four joynts and one Nail; the first joynt is joyned to the Breast; the second joyned to the first, is somewhat bent, as is also the third; but with∣all of a more horn-like substance than the other, and having small points sticking out like teeth of a sad Red colour, and with many hairs on the sides. The fourth joint is very small and armed with a Nail, in which are very neatly placed the small muscles with their in∣sertions, which very curiously move the joints of the horn-like bony legs.

At the Second ring of the Breast, being the third of the body, which seemeth most properly to repre∣sent the Back, and which is covered above, and under with a horn-like bone, appear fastned the * second pair of Legs, containing each five joints, and one nail, here and there beset with hairs. Somewhat more backward appear on each-side the * knobs, or wing∣cases, in which are inclosed the first pair of wings: These are here and there interwoven with Air-vessels which appear on the outside like common Veins, or Nerves. When the Worm is ready for shed∣ding its Skin, these inclosed wings neatly and curi∣ously folded appear through these inclosing films or cases.

At the Third Ring of the Breast being the Fourth of the Body, appear the Second pair of wings which are much smaller, and wholly covered with the first pair, which also in a manner cover the last pair of Legs, containing also each five joints and one nail, and beset with several hairs for adornment.

The First Ring of the Belly, or the Fifth of the whole body, appeareth smooth and even, without conjun∣ction of Legs, Wings, or ought else: To the Six fol∣lowing Rings on either side of the Belly are neatly ad∣joyned * the always trembling and moving Gills, with which according to Clutius the Worm swimmeth; but mistakingly, for these parts are truly the Gills of this Worm: in Crabs, Lobsters, and the Zeekatten,Page  13 which in many things agree with the form of these Worms, are found the same parts, and placed almost in the same manner, however with this difference, that in the Lobsters and Crabs they are inclosed in the hard Scale that covereth its back, and that in them they are placed higher in the body than in our Worm, as it also is in the Zeekatten. In the Figures of Kracht are Twelve of these Gills, represented on each side, but by mistake, for there are in all but Twelve, viz. Six on each side.

The Eighth and Ninth Rings of the Belly, or the Twelfth and Thirteenth of the Body, are wholly smooth and even, but the Tenth Ring of the Belly, and Fourteenth of the Body is adorned with * three hairy and bushy Tails, besides two crooked appendices which in the Females are not so visible, and in the Males have some other appendices.

As to the Colour of the Worm, the smallest are of a pale Blue, somewhat inclining to Grey, which ra∣ther proceedeth from the transparent Intestines, than from the true Colour of the Worms outside; also the eyes in all these Worms are a Brown black, and the Black is speckt with pale Brown specks, the which ac∣cording to the age of the Worm grow blacker. The Beak of these Worms is pale, with sad red teeth, as are also the Two tooth-like Sheres or Cheeks, which are as it were a part of the mouth: the hornlike bony parts of the Legs and the Nails of the feet, are likewise a sad Red.

The Wings which as it were bud forth change gra∣dually from a Pale into a Yellowish Colour, which in time further changeth into a Brown blue, till at length it becomes of a Brownish black. The whole Worm in time attaineth a pale Yellow, and the Blackish spots on its back, which constitute the upper parts of the Belly, are gradually changed into a deeper Colour.

Next in this Worm is to be considered the Sex. The (a) Male hath its Eye in largeness double to that Page  14 of the (b) Female. The body of the Male is commonly much less than that of the Female, which according to my observation is the same in all Insects, and is so contrived by Nature, or rather by the Omniscient God of Nature, that for the great number of Eggs the Fe∣male beareth, it might have a sufficient containing place. The Tails of the Male are the longest; besides they have three or four other appendices which in the Fe∣male are hardly visible, and of which some appear on the sides, and some under. The Male represented in the first Figure of the second Plate is the biggest I have ever seen, notwithstanding of Females many larger are found.

Concerning the Nature of this Creature, I pretend to little experience thereof, only I can assure you that among all the diverse sorts of Insects I have been ac∣quainted with, I never met with one better natured and more harmless than this; for how often or how much soever it is touched or handled, it seemeth always to be well pleased; and left at rest, it immediately be∣taketh to its work of making its Cell. Only I have ob∣served in the smallest sort, that when they are handled somewhat too hard, they bend their head toward their breast, and thereby make themselves as it were stiffer: Among all its actions, none is more strange than the motion of its Gills, of which it hath on each side of its body (c) Six, which are moved so orderly and con∣tinually trembling, that it is admirable.*