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 ...

CHAP. VI.

The Anatomy of the inward parts of this Insect.

HAVING describ'd the Egg, the Worm, its Nourishment, & duration of Life, its outward parts and its nature; I could now fitly proceed to its Change; but for that this Change is so extreme sudden as con∣sisting alone in the shedding of two Films, and some members, I judged it better for the more clear un∣derstanding of the difference between the Insect swim∣ming, and the same Flying▪ (that is, between the Worm and the Ephemeron) first to consider the inward parts, the rather also for that we discern the same parts in both forms of this Insect.

And now that I have undertaken to describe the in∣ward parts of the Worm, and that to effect it, I en∣ter in a path untrod before, yet will I not with Clutius, bewail the want of Books Treating hereof: for besides that Nature it self best discovereth its wonders, and the Books are so far only to be received, as they agree with the truth of the natural appearances of things; I therefore pity those who depending on the experien∣ces of others receive also therewith their endless un∣truths, and therewith deceive their Readers. Second∣ly it is impossible, in the variety of Experiences, by our Conceptions and Reason alone to keep the right path of truth, and with a clear Judgment to pass a true sentence on the observations of others; the more for that we find the most certain Experiences not agree∣ing with our judgment, or rather prejudice, to be ob∣stinately rejected: wherefore I appeal to the Experi∣ences themselves, notwithstanding I might complain, that for want of a sufficient number of Worms, I could not Anatomize their parts to a full exactness, nor to

my own satisfaction. But afterwards I have learned that the Works of God are unsearchable and incompre∣hensible as is his Being. Wherefore we need not fur∣ther search into these his Works, than with admira∣tion of our ignorance in the same, to Praise and Love their Maker.

That I may as much as is possible clearly represent my Observations, I shall withal describe the manner I have used in the Year 1670. to attain the true Dis∣section of the parts of the Worm, for I will at no hand either deceive my self or others. But before I proceed to the description of the Intestines, I shall to assist the memory, in short, enumerate all the outward parts observable in the Worm, and then, which are the in∣ward parts in the Male, and which in the Female.

The outward parts of the Worm are the Head, the Scull, the Horns, the Eyes, the Teeth, the Beak, the Tongue with its hairy Films, which appear in the Worm in the same manner as in the Lobster; the Breast, the Legs, the Nails, the Wings, the Belly with its appurtenances, the uppermost twelve Gills, and the under ten Finns, the Tails with their appendices, and lastly the openings of the Air-vessels under the breast.

The Inward parts in the Male besides the Bloud and the Films, are the Muscles, the Fat, the Stomach, the Guts, the Lung-vessels, the Heart, the Medulla spinalis, and the Seed-vessels.

In the Female having the same parts, is alone this difference, that in stead of the Seed-bladders or Milt, is found the Egg-cluster, which is inclosed with thin Films, throughout woven with very many air-vessels.

But whereas for want of a sufficient number of Worms, I have not exactly enough examined the in∣ward parts of the Head and Eyes, I shall therefore speak little of them, as also of the parts of the Breast which for the most part is filled with the Muscles of the Legs and Wings.

When a Male Worm (easily distinguished by the largeness of its eyes) is placed on a small Deal board, covered either with black paper or linnen which spot∣teth not, with its belly upwards, and there fixed with a very fine Needle, you will find immediately issue out of the wound in the Skin, a thin watery moisture which is the true bloud of this Worm, however it appeareth not of a Red colour as in Earth-worms, in which, as in Four-footed Animals it is Red. To open the Skin, there is nothing more fit, than a very sharp and fine small Scissers, for that the Lancets, although never so sharp, are not in this work useful, for they alwayes tear up some of the parts and strain them asunder; especially when they are of unequal hardnesses.

When with a sharp fine Lancet, or the point of a sharp grounded Needle, you leisurely and with patience separate the upper Skin from the under parts, then ap∣peareth immediately the under Skin very thin and filmy, which, raised with discretion, the Muscles of the Belly appear, and not only those Muscles which extend in a straight line from one Ring of the Body to the other, but also those which are placed oblique, and transverse, and others also which serve to the motion of the Gills, the second Film appeareth also like threads, and seemeth to be fast joyned with the forementioned Muscles.

Next the Muscles, appeareth and is fast joyned to them a very fine and thin Film, which I judge to be the Peritonaeum, above and under the same appeareth the Fat, which is composed of small and very thin White bladders, which contain in them the true Fat, in the form of a liquid Oil; when these bladders are viewed without a Microscope, it would easily be judged they were the Fat it self, whereas they are but as the thin and extreme tender Vesicles thereof, which con∣tain that liquid Fat. Like as it is also in man, and all other beasts, as will appear when these Fat-containing Vesicles, which are of a like proportionate magnitude

shall be view'd by a Microscope. The younger the beasts are the better this Fat appeareth, for then it is spread here and there on the Films, and not so close placed up together as in beasts of more Age.

Next appeareth the (a) 1.1 Stomach, with the Guts thereon depending, viz. the Throat-gut, or Gula, otherwise the upper Gut of the Stomach, which shoot∣eth forward in the form of a thin thread from the Mouth or Cheeks through the back and breast, and constituteth the upper part of the Stomach. Where this small Gut is joyned with the Stomach, it appeareth commonly straitned, * 1.2 which also appeareth in the lower part of the Stomach, otherwise the nether * 1.3 mouth of the same.

The Stomach * 1.4 notwithstanding it is composed of several parts, yet seemeth to be constituted of a thin and very tender Film inwardly beset with rimples or very neat pleats, outwardly it appeareth wholly smooth and extended, especially being filled with food, or blown full of Air with a fine Glass pipe; Veins and Arteries there appear none, for the watery colour of the bloud hindreth the discerning of those parts, and for which cause these Insects are named Exanguious, or without bloud.

Notwithstanding the * 1.5 Stomach appeareth sup∣plied with many small Veins which seem to be bloud-vessels, yet being viewed with a Microscope they clear∣ly appear to be branches of the (b) 1.6 Lung-vessels, which communicate their Branches not only to the Sto∣mach, but to all the outward and inward parts of the body,* 1.7 so that the very Bones and Nails are furnished therewith. The (c) 1.8 Guts adjoyned to the Stomach appear both in form and constitution threefold, as the inward bended or * 1.9 thin Gut. The thick or * 1.10 pleated Gut, and the straight * 1.11 or terminating Gut, within the thin Gut, somewhat low backwards appear some Pleats * 1.12 like half circles in the same manner as the Valves in the thin Guts of men, where

they are named by Anatomists Annular or Conniven∣tes. Somewhat lower where it formeth the (E) thick Gut appear somewhat long strokes, which are very neat and lively, like so many long and extended Mus∣culous threads in the hollow thereof, which agrees somewhat with the Boeck, which in four-footed Crea∣tures is a part of the Paunch; next followeth the (F) straight Gut which appeareth very neatly pleated, till it extendeth as it were out of the body with an indiffe∣rent opening at that end by which the Excrements are sent forth.

The * 1.13 Stomach is placed between the 4th and 5th Ring of the body,* 1.14 where with the thin Gut it takes up all the remaining part of the Belly, as the 6, 7, 8, 9,* 1.15 10, and 11th Rings, whereas the three last of the body as the 12,* 1.16 13, and 14th contain the thick and straight Gut. Like as the Stomach is furnished with a great number of Air-vessels, so also are the Guts, and espe∣cially the straight Gut, and that chiefly in that part, where it is furnished with (a) 1.17 two Muscles for pres∣sing out its Excrements.

And because the Worm is fed with Clay, the Sto∣mach and Guts commonly appear filled therewith. This Clay doth almost always appear through the Stomach, the Guts, and also through the whole body, but it is most visible through the back; by which transparency of the Worms body, it hapneth that the Worm at diffe∣rent times appeareth of different colours, according to the colour of the Clay it feedeth on, viz. Paler, Greener or Wanner; or more or less digested or chang∣ed in the Guts.

When the time approacheth that the Worm is to Change into a Flie, then appeareth no Clay at all in the Guts, the same also hapneth in Wood-worms, the Worms of Bees, Silk-worms, and several other Insects, which at the time of their Change become as clear and transparent as Crystal, and some other Insects are thus transparent during their whole life, so that their Veins

and Intestines with the motions of the same within their body can be clearly discerned.

Among the inward parts of the Ephemeron, are very considerable the (a) 1.18 Lung-pipe, the Air-pipe, or Wind-pipe, as the same part is named in Birds, Beasts and Man;* 1.19 this Air-pipe or vessel is not constituted of one single trunk, as in the forementioned Beasts and Man, but of two chief Trunks, which are placed on each side of the body, curving Snake-like, and that not only in the Breast, as in our bodies, but also in the Head, the Belly, the Legs, and the Wings; so that the Stomach and the Guts, together with the Muscles and Sinews, are as it were fed with Air, which truly is very wonderful, for that the Reason for which it is so formed, is to us wholly incomprehensible, and teacheth us that God in the incomprehensibleness of his works is to be adored.

The Fabrick of the Lung-vessels in this Insect, as in all other Insects I am acquainted with, is constituted of innumerable stiff and curled-like parts, which in the form of knotted Rings are joyned together, and so close united by means of very thin films drawn over them, that they very fitly contain the Air in them, and send it to all the parts of the body backwards and forwards.

When the Worm sheddeth its Skin, I believe, the Lung-vessels also shed a Skin, notwithstanding I have not yet seen it, for at that time when I hapned to make these observations, I knew not of it. In the Silk-worms is this shedding of the Skin of the Lung-vessels so considerable, that all humane understanding must stand amazed thereat: for in that very small time when the Silk-worm sheddeth its Skin, several hun∣dreds of Air-vessels in its body also shed their Skins, being very thin films, all made up of those Rings before-mentioned, which would seem incredible in the Rela∣tion if I my self had not seen it distinctly, and had shewn it also to others.

The Colour of these Lung-vessels is a Pearl colour somewhat Grey, which as they come to change their Skin, changeth into a clear and shining White, for which cause they are much Whiter in the Flies than in the Worms; they spread throughout the whole body, to Communicate Air to all the parts outwards and in∣wards, so that those two great and remarkable (a) 1.20 Air-vessels, which appear placed on each side of the Worm, send to all parts of the body their Branches,* 1.21 as in the Head * 1.22 to the Nerves and Brains; in the Breast * 1.23 to the Muscles of the Legs and Wings; in the Belly * 1.24 to the oblique and straight thread-like Muscles. As also to the (EEE) Medulla Spinalis, to (FFF) the Milt or Seed-vessels of the Male, to (GG) the hairy Gills, to (b) 1.25 the Stomach and (c) 1.26 Guts, to (III) the outward Skin, to (KK) the Film of the wings, to (d) 1.27 the Egg-cluster in the Female, to the Film (MM) that covereth the Egg-cluster, to the (e) 1.28 Eggs, as they are taken out of the body, and to the (f) 1.29 heart.

I have had much trouble to discover the outward openings of the Lung-vessels, for they open neither in the Mouth or Throat as in other Creatures, and for that Reason they lessen gradually as they nearer approach the Head, whereas otherwise they ought there to widen, after a long search they seem to me to have their open∣ings, under and in the sides of the Breast, almost in the same manner as I have afterwards observed it in Grashoppers, where these openings are easier to be seen; but here in our Worm, by reason of its living in the Water and Clay, are less, and therefore more trouble∣some to discover. In the Silk-worms these openings of the Air-vessels are more visible, for they have Ten on each side of their body, viz. Eighteen large ones, and Two lesser, which last not having any Brown spots are not so visible, and never appear clearer to sight than when the Worm sheddeth its Skin, when out of all these Twenty openings of these Air-vessels the shed Films thereof may be seen to issue out,

From these Observations, appeareth very clearly the reason why our Worms rise higher into other Cells when the water of the River increaseth, for that some∣times they must draw fresh Air, and breath, for which cause it may also be said, that they follow the falling water, lest they should be too much dryed up by the surrounding Air, and that their vessels through the dripping out water might be in danger of closing.

These Lung-vessels are best discovered when the Worms have been dead for some days, and that their inwards are become blackish, for then they appear very clear to the sight, which happens for that they they are of a Pearl colour, and like new boil'd Silver, and also for that through their stiff and hard matter of which they are made, they are not so subject to rot, for which reason also at that time they better keep their Figure and roundness.

When with a Microscope you view these Worms on their Breast and Belly, the whole belly seemeth as interwoven with Silver-white vessels: But now to know truly whether they contain Air in them, lay them only in a drop of water, and then close or press them with the point of a Needle whereby the inclosed Air will presently appear; when these Creatures are Dis∣sected under the water, and that with fine Scissers you clip off some of their Lung-vessels, they rise imme∣diately to the Surface of the water, which also do all the parts of the vessels broken off, with their ends up∣wards; in a dried Worm Dissected, these Vessels are very easily discovered, because by their curled-like Rings they remain constantly open, how much soever the other parts dry up.

One of the most remarkable things observable in these Lung-vessels is the great number of them ex∣tending to the (a) 1.30 Gills where are * 1.31 three chief of them represented as cut off; the middlemost is al∣ways * 1.32 black, which notwithstanding just in the middle appeareth transparent White, the other two

appear on each side of the middlemost which is Black, and they shoot out a great number of Silver white Vessels * 1.33 in the Gills, which vessels are not very visible by their Colour, by reason of the very bright ap∣pearance of the Gills, which are in number Six (b) 1.34 on each side of the body, and are pure shining White, under the same,* 1.35 on each side are the Five (c) 1.36 Finns of a Yellow Colour with which the Worm swimmeth.

R* 1.37I had made some other Observations concerning the Gills and their Vessels, which are missing, and which I cannot now find, and the Contents of them is wholly out of my Memory; so that I remember not what is the use of * 1.38 that Feather-like hairy part which is seen under the first and uncut pair of Gills, as also whether it is found under the other Gills, what Communication those Gills have with the Lung-vessels, and the (d) 1.39 Lung-vessels with * 1.40 the heart, I know not, so that I can relate no more thereof than what is repre∣sented in this Delineation,* 1.41 where all the Air-vessels about the heart are not represented, to prevent confu∣sion, only some are represented whole, and the others * 1.42 as cut of.

I have also in all my delineations, not observed an exact proportion as to the size of the parts, for that seemed to me a too tedious labour and of small use; so that I have delineated one part somewhat larger than the other, never thinking to have made these my Ob∣servations publick, till I had anew more examined them all over, which I also afterwards found more ne∣cessary, as well for the greater knowledge I afterwards attained concerning the parts of Insects, and also a greater readiness in the Anatomizing of them, but the kind Reader is desired to pardon what is wanting, which I am conscious is very much; and who is able in many years to describe this Insect, and the wonders therein observable, which is the reason that I Commu∣nicate it thus to the world; the more for that I now am resolved to addict my thoughts more to love the Crea∣tor

of these things, than to admire him in his Crea∣tures.

The (a) 1.43 heart appeareth placed above in the back as it is in Silk-worms, the Worms of Bees, Wood-worms, Caterpillars,* 1.44 and other like Insects, here and there it appeareth somewhat * 1.45 swelling out, like as in Silk-worms, and noted by Malpighius, and from whence he concludeth, but not rightly, as I conceive, that in the same Worm should be more than one heart; I have seen this heart move in the Ephemeron, but very disorderly, and what I have here represented in the Figure is but a part of it, and I have wholly forgotten in what part or division of the body it is placed.

The (b) 1.46 Medulla Spinalis in this Insect, is like that in all the other sorts that I have yet dissected, very wonderful and observable;* 1.47 it contains Eleven Swellings Oblong and Oval, the First of which representeth the Brains where the * 1.48 Optick Nerves very visibly appear shooting forth in the same manner like as the other Nerves of the Body shoot out from the other Ten Swellings, but in greater number from the upper Swel∣lings than from the under. Here and there the Medulla Spinalis appeareth very neatly fastned as it were with * 1.49 bands, which are made partly of an horny bone, and partly of a Sinewy substance, as is chiefly appearing in the Breast, where the Medulla Spinalis shooteth forth very strong Nerves to the * 1.50 Muscles which move the Leggs and the * 1.51 Wings in like manner as it doth to the (cc) 1.52 Muscles of the Gills and the Finns.

Out of every Swelling or Node of the (d) 1.53 Medulla Spinalis shoot always two very strong Nerves which joyn in the next Swelling,* 1.54 and enlarges the same whereby the Medulla Spinalis appeareth throughout as if Split and Gaping; but as it is naturally placed in the body that gaping appeareth not, for whereas there the arising Nerves lie close one to the other, they seem no•• gaping, as Tab. 4. Fig. 6. may be seen where the Medulla Spinalis is represented, as it appeareth naturally

in the body, as also the Fourteen divisions correspond∣ing to those of the body in which it is placed.

When you would see the Medulla Spinalis without hurting the Worm, you must blow the same up with Wind from behind, whereby the Swelling Guts will press so strongly against the transparent Skin that you may very conveniently see the Natural position, or shape thereof, and that as well without as with a Mi∣croscope, but this is chiefly practicable in the Male.

As all the other parts of the body have their Air-vessels, so hath also the Medulla Spinalis, and that in a great number, so that even the Brain and the Nerves, receive a continual refreshment of Air. Whether it hath Veins and Arteries I have not seen, yet I firmly believe it; but in the Silk-worms I have seen it very plainly, viz. several Vessels and Veins issuing out of the heart, which I filled with a Coloured Liquor, notwithstand∣ing I cannot hitherto certainly affirm whether they are Veins or Arteries.

Concerning the (a) 1.55 Seed-vessels, or Genital parts, they are as visible in the Male-worm the day before he sheddeth his Skin,* 1.56 as in the Male of the Ephemeron, which hath shed his Skin; on both sides of the Stomach and the Guts appear these Seed-vessels, which wholly agree with the Milt of Fishes, notwithstanding like the Seed-bladders in men, they are somewhat crump∣led and Pipe-like in shape.

In which they also agree with the Seed-bladders of some Four-footed Animals, as with the Moles, Hedge-hogs, and the like. The shape of these Seed-vessels are * 1.57 oblong, taking up the whole belly as may be seen in the Figure thereof, where some of them is represented without the body and somewhat greater than that in the body, those Vessels contain a very white Milky liquid substance which is the Seed, the Vessels themselves also are very white and constituted of a thin Film, having here and there many Air-vessels interwoven in the same.

In the nethermost Rings of the Belly appear two other (a) 1.58 parts also, as it seemeth pertaining to the Seed-vessels, which seem to have the same opening with the Seed-vessels, and with the * 1.59 Guts, which I could not so exactly observe when I made the Dis∣section, for that a great number of these Insects are requisite to be opened, to repeat the same search, and to find that in the following which could not be found, or was omitted in the former, but this number of these Insects is not always attainable.

The (b) 1.60 Egg-cluster in the Female is double, and placed in these Insects in the same manner as the Roe in Fishes. When with a fine sharp-pointed Scissers the Skin of the Belly is a little clipt of, the (c) 1.61 Egg-clusters appear immediately,* 1.62 which are placed on each side of the Flank of the Belly. In the middle between the same appear the * 1.63 Stomach, and the Guts shining through, but somewhat darkly, which are indifferently fast joyned to * 1.64 the Films of the Egg-clusters; the Stomach and Guts appear the clearer by how much they are more filled with Clay, their nourishment; whereby also the Eggs are more visible, which by that difference in colour appear the Whiter.

This double Egg-cluster is supplied with an innu∣merable number of Air-vessels, which are as it were knit together with a thin Film, enclosing the Egg-cluster, and by which those Air-vessels are conducted to the enclosed Eggs. When the Film is separated by the point of a sharp and a well cutting Needle, and that a part thereof with the Eggs is laid in a Spoon with wa∣ter, the Eggs immediately separate one from another, and there remaineth a tender bunch (d) 1.65 of very thin Veins as their Fibres, Pearl coloured, which Fibres I conceive for the most part to be constituted of Air-vessels.

The (a) 1.66 Magnitude of the Egg is so small, as to be hardly visible, and therefore ought to be viewed by a Microscope, being laid on Black or Blue paper which

much assisteth to the clear perception of them.

The Form of the Egg is a flattish round and oblong, and inclosed in a reasonable strong Skin, which viewed through a Microscope appears cloudy; its Colour is White, like the inward Film of an Egg-shell: The smalness of the Egg seemeth to be the reason why the Worms are Three years growing before they come to their full growth and ready for change.

Notes

• (a) 1.1

  Tab. 4. Fig. 5.
• * 1.2

  A
• * 1.3

  B
• * 1.4

  C
• * 1.5

  C
• (b) 1.6

  Tab. 3. Fig. 1.
• * 1.7

  AA
• (c) 1.8

  Tab. 4. Fig. 5.
• * 1.9

  DD
• * 1.10

  E
• * 1.11

  F
• * 1.12

  G
• * 1.13

  C
• * 1.14

  4, 5,
• * 1.15

  6, 7, 8, 9, 10, 11,
• * 1.16

  12, 13, 14.
• (a) 1.17

  Tab. 4. Fig. 1.ii.
• (a) 1.18

  Tab. 3. Fig. 1.
• * 1.19

  AA
• (a) 1.20

  Tab. 3. Fig. 1.
• * 1.21

  AA
• * 1.22

  BB
• * 1.23

  CC
• * 1.24

  DD
• (b) 1.25

  Tab. 4. Fig. v. C.
• (c) 1.26

  Tab. 3. Fig. 1. H.
• (d) 1.27

  Tab. 4. Fig. 1. LL.
• (e) 1.28

  Fig. 7. N.
• (f) 1.29

  Fig. 4. TT.
• (a) 1.30

  Tab. 3. Fig. 1.
• * 1.31

  PPPP
• * 1.32

  QQ
• * 1.33

  GG
• (b) 1.34

  Tab. 2. Fig. 1.
• * 1.35

  FF
• (c) 1.36

  Tab. 3. Fig. 1.
• * 1.37

  RRRR
• * 1.38

  SS
• (d) 1.39

  Tab. 4. Fig. 4.
• * 1.40

  TT
• * 1.41

  OO
• * 1.42

  VV
• (a) 1.43

  Tab. 4. Fig. 4.
• * 1.44

  TT
• * 1.45

  XXXX
• (b) 1.46

  Tab. 3. Fig. 1.
• * 1.47

  YYY
• * 1.48

  **
• * 1.49

  ZZ
• * 1.50

  aa
• * 1.51

  bb
• (cc) 1.52

  Tab. 4. Fig. 1. CC
• (d) 1.53

  Tab. 3. Fig. 1.
• * 1.54

  EE
• (a) 1.55

  Tab. 3. Fig. 1.
• * 1.56

  FFFFF
• * 1.57

  FFFFF
• (a) 1.58

  Tab. 3. Fig. 1. dd
• * 1.59

  e
• (b) 1.60

  Tab. 4. Fig. 3.
• (c) 1.61

  Fig. 1.
• * 1.62

  LL
• * 1.63

  ff
• * 1.64

  MMM
• (d) 1.65

  Tab. 4. Fig. 7. g.
• (a) 1.66

  Tab. 4. Fig. 2.