Mikrokosmographia a description of the body of man. Together vvith the controuersies thereto belonging. Collected and translated out of all the best authors of anatomy, especially out of Gasper Bauhinus and Andreas Laurentius. By Helkiah Crooke Doctor of Physicke, physitian to His Maiestie, and his Highnesse professor in anatomy and chyrurgerie. Published by the Kings Maiesties especiall direction and warrant according to the first integrity, as it was originally written by the author.

CHAP. IIII. Of the Fat & Muscles of the Eyes.

THE parts wherof the Eye consisteth, are fiue Fat, Muscles, Vessels, Coats * 1.1 and Humors. The Fat which Anatomists do some of them call Adeps, som of them Pinguedo, is verie plentifull about the eyes [Tab. 1. Fig. 6. T] espe∣cially it is found in those spaces which are betwixt the Muscles and the Nerues. It is also more plentifull at the vpper Muscle, because that is greater and ordained for more frequent & strong motions. In like manner toward the lower side of the Orbe there is plentie of fat, which like a pillowe is laide vnder the Eyes, * 1.2 that with their weight they should not presse themselues vpon the bones. Againe, be∣twixt the Muscles and the globe of the eie there is aboūdant fat, that when the Muscles worke the eie should not suffer compression. Finally, there is also fat found neere the Veines and Arteries, whereby the vessels are smeared ouer and their distention preuen∣ted in the motion of the eies.

The vse of the fat, in as much as it is warme, is to heate the eye which by nature is wa∣terish and cold, and beside to defend it from the coldnesse of the outward aire. And that is * 1.3 the reason why we neuer feele any manifest coldnesse or stiffenesse in our eyes. Againe, the humidity of the sat doth moysten the Muscles, that they becōe not exiccated or dried vp in their often motions. The softnesse of the fat keepeth the eyes from being offended by the bones about them. The vnctuosity or oyly fatnesse maketh their motion swift and facile, and beside, when the Muscles are somewhat dried, because of their motion and as it were consumed, it affoordoth Aliment vnto them.

The Muscles of the Eyes, although they belong to another place, namely to the Booke * 1.4 of the Muscles, yet because wee are desirous to absolue the History of the Senses in this present Booke wee will take liberty to varry something from our scope and set downe as perfect a description of them heere as we can. And that was the reason why before we were so large in describing the Muscles of the eye browes and eye-liddes, concerning all which we will spare our labour and yours when wee come to the History of the Muscles. Because therefore our eyes were giuen vs as spies and scout-watches that wee might pur∣sue things profitable and eschew that that is hurtfull, Nature made not the eyes immoua∣ble, for then they shoulde haue discerned onely that which is opposite vnto them, for so saith Aristotle in his second booke Departibus Animalium and the tenth chapter Gerimnus * 1.5 per directum, that is, we see by a straight line; not in euery position saith Galen in the eight Chapter of his tenth booke de vsupartium, because oblique, side, backward, higher and lower Obiects do not fall in with the ball of the Eye. Nature therefore hath so disposed the Eyes that they may moue & turn themselues on euery side at their pleasure. But Galen addoth in the place before quoted, that not only the eyes are moued but also the neck and the head are made mooueable for the behoof of the eyes, because there are six positions of place vnto all which the eye ought to mooue; that is to say, vpward downeward, for∣ward backward, on the right hand and on the left.

It was therfore of necessity that the eyes shuld haue other helps beside their own motion, for the eyes are not mooued forward and backward, partly because there was no absolute

necessity, and partly because it was impossible; it was not necessary they should moue for∣ward sayth Aquapendens, because the eye doth not attaine vnto the light but the light vnto the eie, which in a moment enlightneth an infinite space euen vnto the eie, yea insinuateth it selfe thereinto.

But the wise Creator hath made amends for the defect of this motion of the eyes by the help of the motion of the head, which out of hād conuerteth it selfe to see those things which the eie could not by his proper motions perceiue. Moreouer, that wee might see * 1.6 whatsoeuer is behind our backe (which could not be done onely by the circumuolutions of the head) Nature hath so prouided that the thighes can carry the body round. In like man∣ner the motion of the eye vpward is assisted by the backeward motion of the head and of the whols spine, which they haue experience of that striue to take view of the pinnacle of a high Steeple: so also the motion of the eye downeward is furthered by that motion of the head and of the necke which is forward.

Seeing therefore it was necessary that the eyes should bee moued with voluntary mo∣tion; and all voluntary motion is made by muscles, therefore our wise Creator hath giuen * 1.7 vnto them diuers muscles whereby their motions are very sudden and expedite. Hence it is that Aristotle in the 8. Probleme of the 7. Section calleth the Eye The most noble part of the body: yet sayth he, the left eie is more nimble then the right. Now whereas the moti∣ons of a mans eye are sixe according to Galen in the third Chapter of his first Booke de mo∣tu musculorum, it followeth necessarily that the eie must haue sixe muscles; but Galen, Ve∣salius and the rest of the Anatomists as Columbus sayth being accustomed only to describe the eies of beastes haue added a seauenth muscle, and those sixe also which they haue de∣scribed they haue misplaced. But we are to describe the muscles of the eye of a man, that seauenth which belongeth to beastes is deuided into two, into three, and sometimes into foure.

In men therefore as we haue said there are sixe muscles according vnto the sixe moti∣ons of a mans eie; foure of which motions are Right, that is to say vpward, downeward, * 1.8 to the right hand and to the left; the two motions remayning are oblique, to which belong two oblique muscles whose vse is to rowle the eie about. Notwithstanding one of these is * 1.9 exactly oblique, the other partly right partly oblique. All these muscles are seated on the backeside of the Eye within the cauity of the Scull, whether they accompany the opticke nerue and so remayning in their position, the eie and they together doe make a Pyramidal or turbinated figure. [Table 1. figu. 6. 7.] Among these muscles the thicker and more cor∣polent are the Right which haue all the same structure, originall and insertion, and do passe * 1.10 straight al along the length of the eie; the oblique muscles are lesse fleshy yet very like one another.

All these muscles of the eie are small that they might be sooner mooued; but that which helpeth most the volubility of their motion is the round figure, which is the nimblest of all * 1.11 others, as we may perceiue by the roundnes of the heauens.

The eie therefore being round as are also the muscles thereof, is euen in a moment con∣ueyed * 1.12 ouer the whole heauen, and the head itselfe is therefore mooued very suddanly and swiftly, because it toucheth vpon the bone whereon it resteth with a narrow point.

The foure Right muscles meeting and touching one another toward the roote of the nerue optick, doe arise with a sharp beginning frō the lower part of the bony orbe which is * 1.13 made by the wedge bone, hard by the passage through which the nerue of sight or the op∣ticke nerue doth yssue. I know well that Vesalius is of opinion that they arise out of diuers parts and into diuers parts are inserted. Againe for their matter, he conceiueth they arise from a commixture of the Dura mater which compasseth the opticke nerue and a nerue of the second coniugation. Platerus thinkes that they arise from the membrane which com∣passeth the orbe of the eye, and that membrane which inuesteth the opticke nerue. Aqua∣pendens imagineth they proceed from the Pericranium or Scull-skinne. Laurentius dispu∣teth about their originall on this manner; They erre, saith he, which thinke the muscles of * 1.14 the eie doe arise from the inner thicke membrane which compasseth the opticke nerue, for this is altogether against sence; they could not sayth hee arise from a membrane nor they ought not. They ought not, because a membrane of an exquisite sence compasseth the nerue, which nerue the muscles in their motions would compresse, and so the sight would be offended. They could not because they are not established vppon a firme foundation. It remayneth therefore, saith Laurentius, that they must arise from the inmost depth of the

[illustration]

Table 2. Figure 1. sheweth many muscles of the Eye in their owne seate.

[illustration]

Figure 2. sheweth the Eye rowled vpward whereby their mus∣cles may be perceiued.

[illustration]

Figure 3. and 4. sheweth the muscles of the Eye, separated be∣fore and behind with their nerues.

[illustration]

Figure 5. Is the Eye of an Oxe, with his muscles seuered as Ve∣salius doth shew it.

[illustration]

TABVLA. II.

[illustration]

FIG. I.

[illustration]

FIG. II

[illustration]

FIG. III.

[illustration]

FIG. IV.

[illustration]

FIG. V.

• A, The eie lid. B, The Tarsus or gristle where the haires grow.
• C, the muscle lifting vp the eye lid.
• D, 1, 3, 4, the right vpper muscle of the eie in 3, and 4, with the nerue.
• E, 2, 3, 4, the right lower muscle of the eye, in 3 and 4 with the nerue,
• F, 1, 2, 3, 4, the right externall muscle of the eye.
• G 1, 2, 3, 4, the right internall muscle of the eye.
• H, 1, 2, 3, 4, the oblique superior muscle or the pulley, whose tendon is marked with a and the pulley with b.
• I 2, 3, 4, The oblique inferior muscle of the eye.
• K 1, 3, the opticke nerue.
• a 1, 2, The tendon of the oblique superior muscle.
• b 1, 2, the sayd pulley, a small gristle where through the tendon doth passe, & in the 3 and 4 pulled from the bone.
• cccccc 3, 4, the mouing nerues of the eies.
• αβ, 5, the second muscle of the eye-lid lying in the cauity of the eye, whose broad ten¦don β is inserted into the eie-lid.
• γ 5, the haires of the eie-browes.
• ♌ •• 5, two right muscle leading the eie vp∣ward and downward.
• ζ n 5, Two right muscles moouing vnto the right and left side.
• B 1, 5, two oblique muscles lightly turning the eye.
• •• 5, the seauenth muscle which may bee de∣uided into more.
• Λ 5, The Opticke nerue.

orbe or cauity. But we rest vpon Bauhines opinion for their originall.

Their whole bodies throughout their whole course are fleshy, and their bellies beare out round as they come forward. But they determine a little aboue the middle of the eye * 1.15 into a broad thinne and membranous tendon wherewith they compasse the whole eye be∣fore, and grow very strongly to the horny Tunicle neare vnto the Iris or Raine-bow in the greater circle: and these tendons ioyned together doe make that nameles coate of Colum∣bus and the white of the eie.

For we conceiue that this whitenesse is caused rather by the tendons of these muscles * 1.16 then that it properly belongeth to the coate which we call Adnata. And so much shal be sufficient to haue spoken in generall of the muscles of the Eie. Now we come to a more particular discription of them one by one.

The first [Table 2. figure 1, 3, 4. ^D fig. 5. ♌] which is the third according to Vessalius, and Galen also in the 8. Chapter of his 10. Booke de vsu partium, is seated aboue; fleshy it is & * 1.17 round, thicker also then the rest, greater and stronger then the second, because it lifteth the eie vpward toward the brow. For there is greater strength required to lift a thing vp, then to pull it downe. The names of this muscle commonly giuen by Authours are, Attollens and Superbus, the Lifter and the Proud muscle.

The second which according to Galen and Vesalius is the fourth [Table 2. figure 2, 3, 4. E. figure 5. ••] is opposite vnto the former and placed in the Lower part; it draweth the eye downeward to the Cheeks, and therfore needed not be so great as the former, be∣cause the eye declineth easily with his owne waight. It is called Deprimens and Humilis; the Depressor and Humble Muscle.

The third [Ta. 2. fig. 1, 2, 3, 4^G. fig. 5, ζ] according to Galen and Vesalius the first, is sea∣ted in the great angle and leadeth the eye inward toward the nose, and is called Addu∣cens and Bibitorius we may call it the Gleeing Muscle.

The fourth [Tab. 2. fig. 1, 2, 3, 4^F. fig. 5, n] which according to Galen and Vesalius is the second, is opposite to the third, seated on the outside of the eye which it draweth to the lesser angle or to the temples, and is called Abducens and Indignatorius, we may cal it the Scu-muscle or the Muscle of Disdaine.

If all these foure worke together the eye is drawne inwarde, fixed, established and conteined, which kind of motion Physitians call Motus Tonicus, wee in our Language * 1.18 cal it a Set or wist-looke. Archangelus is more distinct in the assignation of the motions of these Muscles, for (saith he) whē as at diuers times they are moued with any pause be∣twixt their motion, then the eye is mooued toward the originall of that Muscle which worketh. But when they are mooued at diuers times without any pause, that is, with im∣mediate successiue motions, then they mooue the eye round: but when they all mooue in the same moment then do they set fixe and establish the Eye immooueable, wherein they are holpen by the fift Muscle, whether all foure doe mooue a part or do worke to∣gether.

The fifth [tab. 2. fig. 2, 3. 4. ^I fig. 5. ^•] which is also according to Galen and Vessalius the fifth, but the sixth according to Fallopius, Platerus, and Laurentius; is seated in the out∣side at the depth of the cauity and ariseth betweene the eye and the Tendons of the se∣cond and fourth Muscles; which is the reason why some haue thought that it taketh his originall from the Eie and is againe inserted into the same. But the very place of his originall is at that cleft which appeareth like a suture or seame of that bone of the lower part of the Orbe which ioyneth the first bone of the iaw with the fourth. Sometimes it ariseth with a fleshy beginning from a bony scarfe. It is slender, round, short and exact∣ly oblique, and passeth obliquely toward the outwarde angle as it were to embrace the eie, and is implanted with a short and round Tendon, degenerating into a thinne and Neruous termination neere vnto the Iris or Rain-bow but obliquely, hard by the inserti∣on of the sixt Muscle, so that sometimes the Tendons of them both, serue one and the same.

To recite heere the contentions and challenges of Anatomistes about this Muscle would rather entangle our Readers minde then giue him any great satisfaction, especi∣ally seeing those learned men to whom so nice disquisitions will not seem tedious, may repaire to those fountaines from whence we haue drawne our by-streame, and therefore we passe on to the vse which is by the contraction of his Fibres to rowle the eie oblique ly downward to the outward angle.

The sixt [Tab. 2. fig. 1, 2, 3, 4. ^H fig. 5 ••] which is the sixt also according to Galen & Ve∣salius, but the fift according to Falopius, Platerus and Laurentius, is seated on the inside * 1.19 and the vpper part, yet vnder the right Muscles, and is partly right and partly oblique. It ariseth from the same place with that Muscle which draweth the eye directly vnto the inner angle at the side of the Opticke Nerues passage, which is in the verie depth of the Orbe.

It endeth as well in man as in bruite beastes into a round, small and long Tendone, * 1.20 [Tab. 2. fig. 1, 2. ^•] almost at the vtmost brimme or edge of the inward angle. This Ten∣don is reflected through a small gristle hollowed like a Caue and scituated in the grea∣ter angle, which Fallopius first of all men called Trochlea or the Pully, & thence procee∣ding obliquely to the right angle [Ta. 2, fig. 2, ^b but in the thirde and fourth figure it is * 1.21 sliuen from the bone] toward the vpper part of the eye, it is inserted betweene the first and the fifth Muscles with an oblique line, all which time the foresaid Tendon is com∣passed about with a certaine Ligament as it were with a sheath.

This Muscle being drawne inward toward his originall with his Tendon he turneth the eye in a circular motion to the inward Angle. These two turning Muscles the one vpwarde the other lower are called Circulares & Amatorij, the rowling or glauncing

Muscles, some also call the sixt Musculum Trochleae, or the Muscle of the pully.

The seauenth Muscle which is for the most part found in brute beastes, excepting the Ape and Fishes, is placed [Tab. 2. fig. 5. x] vnder the former sixe, and hath of it selfe that figure which the former sixe do together make. It is short and compasseth round about * 1.22 the Opticke nerue, [Tab. 2. fig. 5. ^Λ] yet is their some fat betweene them. Proceeding forward it is dilated and embraceth the whole globe of the eye euen to the roote. It ma∣keth also a circle like as the foure first did at the Rainbow make a circle with their chords or Tendons: at his insertion, which is into the hard tunickle of the eye, it becometh fleshy and may be diuided into three or foure; so as Galen in the fourth chapter of his fift booke de dissectione Musculorum maketh a doubt whether it be one Muscle, or double or treble.

The vse of this Muscle is to tie vppe and strengthen the eyes of brute beasts hanging alwayes downeward, that they should not fall with their own weight. It also incompas∣seth the nerue Opticke therby making his passage, not only straight but also warranteth it frō distention & frō leaning against the bone in violent concussions or suddain motions. Galen addeth in the booke before named, that in that motion which we called Tonicall or the fixing of the eye; it establisheth the same when we would accurately discerne any small body; for he supposed this Muscle also to be in men.

But Nature or the God of Nature rather, did not see it needfull for mankinde, be∣cause * 1.23 his countenance is erected vp to heauen, and if at any time hee bee constrained to looke downward, he hath all the foure right Muscles with their ioynt strength to sustaine his eye, because their Fibres grow to the Membrane which compasseth the Orbe.

Falopius addeth an eight Muscle found in Oxen which draweth that gristly Membrane which Aristotle in the twelft chapter of his second booke de historia Animalum calleth the skin of the angle, with which Membrane brute beasts do blinke when they feare lest any thing should fall into their eyes: vnlesse any man shall thinke this is a part of that Muscle which draweth the eye to the outward angle.

To finde out these Muscles of the eye, when the Braine is taken away you must cut * 1.24 the Orbe at each corner euen to the Opticke nerue with a saw, hauing a great care lest the Trochlea or pully which is in the inner angle be offended.

Next you must separate the Pericranium from the bone, and bend the vpper part of the Orbe backeward, then take away the fat and so shall you perceiue the Muscles of the eye lids, and of the eyes themselues together with their vessels; and if you would obserue the proper and peculiar motion of euery Muscle, you must preserue them in their proper positions and tie to euery one of them a thred not farre from the Tendons, then draw the thred and the draught thereof will describe vnto you the vse of the Muscle to which it is tied.

You may also take the eye whole out of his Orbe together with the Trochlea, which is in the inner angle and so demonstrate what you please. And thus much shall bee suffi∣cient to haue spoken of the Muscles of the eyes. Now we proceede vnto their vessels.

Notes

• * 1.1

  The partes whereof the eie is com∣pounded.
• * 1.2

  In what pla∣ces of the eye the fat is foūd
• * 1.3

  The vses of the fat.
• * 1.4

  Why the mus∣cles of the eye are described in this place.
• * 1.5

  We see by a right line.
• * 1.6

  As also the motion of the thighes.
• * 1.7

  Why their muscles are many.
• * 1.8

  Why sixe,
• * 1.9

  How many mo••••ons the eie hath.
• * 1.10

  The figure of the eie.
• * 1.11

  Why the mus¦cle▪ 〈…〉〈…〉
• * 1.12

  Why round,
• * 1.13

  The right mus¦cles.
• * 1.14

  Diuers opini∣ons about their original
• * 1.15

  Their inserri∣on,
• * 1.16

  Whence the whitenes of the eie pro∣ce••deth.
• * 1.17

  A more parti∣cular descrip∣tion of the se∣ueral muscles.
• * 1.18

  Their Vse.
• * 1.19

  His original.
• * 1.20

  His end or Tendon.
• * 1.21

  His progresse. Falopius his Trochlea or pully. His insertion.
• * 1.22

  The 7. belon∣ging to a beast.
• * 1.23

  Why a man hath not the 7. Muscle.
• * 1.24

  How to make diffection best to find out these Muscles