A systeme of anatomy, treating of the body of man, beasts, birds, fish, insects, and plants illustrated with many schemes, consisting of variety of elegant figures, drawn from the life, and engraven in seventy four folio copper-plates. And after every part of man's body hath been anatomically described, its diseases, cases, and cures are concisely exhibited. The first volume containing the parts of the lowest apartiments of the body of man and other animals, etc. / by Samuel Collins ...

CHAP. XXIII. Of the Creeping of Animals.

ANother kind of Progressive Motion, is that of Creeping, * 1.1 seeming to be the meanest of all, wherein Animals destitute of Legs and Feet to support them, do Creep along sweeping the Ground with their Bel∣lies in a kind of Undulating Motion upon the Surface of the Earth, and do move laterally in divers Arches, made sometimes to the right, and some∣times to the left side; which is celebrated by several Machines of Motion, seated on each side of these Reptiles, and fixed to the sides of the Spine, consisting of many Vertebres, from which divers short Muscles do arise and into which they are inserted; and by contracting themselves toward the Head, * 1.2 do abbreviate the Body, by making several segments of Circles alternately in each side, thereby drawing the Body forward, part by part, as step by step.

So that Creeping is acted by many Flexions not made by Angles, lest the Ligaments tying the Vertebres of the Spine together should be Lacera∣ted, and a Laxation be made; whereupon the Motion of Reptiles, is ma∣naged by divers strong short Muscles, bending the Body into many arched

Positions, most proper and agreeable to this Fluctuating Motion (as very easie to Reptiles) which is exerted in hollow Flexures, made by Contra∣cted Muscles in one side, relaxing the Antagonists of the other, modelled into a convex Posture; whereupon the Muscles of each side being recipro∣cally contracted, and relaxed in Motion and Rest, do alternately make va∣rious Maeanders in their concave and convex Surfaces, in order to transfer their long slender Bodies piece by piece, from place to place, by many suc∣cessive segments of Circles, resting upon divers centers of Motion, very visible in Reptiles; as Snakes, Vipers, Glow-worms, and the like, which are not only dressed with Lateral, but also with Muscles, taking their rise from the Neck, and inserted into the posterior region of the Head, which being Contracted, lift up their alternate arched Motion, whose intermedial points are kept in a right posture with the Head, always conserved directly forth-right, while the Body sporteth it self on each side, in various succes∣sive segments of Circles, in reference to Progressive Motion.

And in relation to repose, Serpents have their Heads enwrapped within many segments of Circles, produced by a general Contraction of all the Muscles relating to one side, drawing all the Vertebres of the Back in a cir∣cumference toward the Head; whereupon all the Muscles of one side be∣ing Contracted, their Antagonists are Relaxed, and the whole Body is moul∣ded into Spires, every way encircling the Head.

Thus far of the first kind of motion proper to Reptiles, * 1.3 called Undula∣tion, most conspicuous in Serpents, Snakes, and the like; whose long Bodies are wheeled this and that way in quicker Motions; whereas the se∣cond degree of Motion stiled Creeping, is more slow and successive, where∣in the Fluctuation of the Body is made by bending not side-ways, * 1.4 but up∣ward: So that some part of the Body is acted with Motion (while the other is composed to rest) in various Postures, succeeding each other, plain∣ly discernable in Silk-worms, which are set before and behind with such small Feet, (that they can scarce be discovered) and between them is seat∣ed so large an Interval, that their Bellies touch the Ground in Motion, which is accomplished by divers Muscles; some placed in the Back, others in the Sides (terminating in the Annular Fibres) which being Contracted toward the Head, and those of the Back making Flexures upward in it, do draw the Body forward toward the Head; so that resting the Posterior part of their Body on the hinder Legs, Silk-worms pull themselves forward, by forming divers Arches in the Intermedial parts, which being afterward di∣stended, their Bodies are reduced into straight Postures.

Other Reptiles, * 1.5 as Leeches and Worms, have another kind of Progres∣sive Creeping Motion, which is not effected either by moving laterally or upward by various Flexures, but long-ways and short-ways by Extension and Contraction, produced by Minute Fibres, as Tensors rendring these Insects more long and slender; and by other Fibres, as Contractors, ma∣king the parts more thick and short, by whose joint assistance of Tensors and Contractors, the bodies of Leeches and Worms are drawn forward in their Anterior parts first, the Center Motion resting in their hinder parts, which at that moment are thickned and immoveable, and afterward move, while they grow long and slender by Tensors: So that first the Anterior parts of these Reptiles are lessened, and moved, and the hinder parts are immoveable as Hypomoclia, and afterward the Posterior Region is lessened, and the Anterior is thickned, being rendred the Center of Motion: Where∣upon (I conceive) the Motion of these Reptiles is celebrated by different

Fibres, as Extensors and Contractors; the first playing in the Anterior parts, draw them out in length, and afterward being shortned into a greater thick∣ness by Contractors, pull the Body toward the Head; so that the Anterior parts being Incrassated and shortned, the Posterior are made slender and lengthned by Tensors, and afterward reduced by Contractors more closely into themselves, pull the Posterior parts forward.

Nature, God's Vicegerent, useth divers Methods in the conduct of Pro∣gressive Motion, and as it is more Excellent, it hath a better Appara∣tus, made of a more perfect and greater number of Instruments, more choice Bones, and better contrived Articulations, and more regular Muscles, the chief Engines of Motion.

Wherefore the methods of Local Motion in lower ranks of Animals, as Insects, and the like, are very obscure and imperfect, as gradually celebrated with more slowness, wherein the whole Body is not moved at once, but one part after another with great industry and time, which is performed in ob∣lique slender Bodies, not supported by the interposition of Articulated Limbs, as so many jointed Columns, but often Sweeping or Creeping upon some Area, with their bare Bellies, which in several parts are lifted up and depressed again to the Ground, to draw the Body piece by piece from place to place.

Before we make any farther progress, it may seem Methodical to be in∣quisitive into the nature of this Creeping Motion, which may be worth our Time, as well as Pains, as being a matter of great Curiosity and Wonder, to understand the great Works of the Creator, in reference to the most Mi∣nute Creatures.

And indeed it is very difficult to apprehend the Method by which Na∣ture proceedeth, in the production of Motion relating to Insects, which is much different from that of greater and more perfect Animals, and is not at all relating to Walking, Flying, Swimming, which require a greater Apparatus of more noble Organs: Again, the conception of this Motion, is perplext in point of its various Modes, as Spiral, Arch-like, &c.

Thirdly, It is difficult to pry into the Nature of it, because the Instru∣ments of it are not very obvious to Sense, by reason of their smallness, im∣perfection, and various confused parts; so that some Animals are furnished in order to this Creeping Motion, with Bones, Joints, and Muscles, the main Instruments of Motion, as Eels and Serpents; but in other Animals they are deficient, as Leeches and Worms, and the like, and have neither Bones nor Joints, but small Annular Membranes in stead of Bones, and straight Fibres in stead of Muscles.

And now I will take the freedom to offer some requisite Conditions, * 1.6 found in Minute Animals, as so many Pillars, upon which all Creeping Motion is built; * 1.7 The first is some immoveable Base or Area (upon which this Mo∣tion is founded) seated without the moved bodies of Animals, which are the subjects of Motion, and are the second requisite of it, and the third and chief are the Machines, or instrumental causes of this Motion.

Local Motion, commonly called Creeping, * 1.8 admitteth a Division into many kinds, as so many Modes of it, which is sometimes Wavelike, di∣versly celebrated; as when the Back is curled above in variety of short Waves, which is evident in Leeches, and Silk-worms; or acted below, when Oblong bodies are rendred Crooked, part after part successively, wherein the Body is moved by degrees, by Spire after Spire, from Term to Term, as in Lampreys, Eels, Congers: But Insects do extend first the

fore part of their Bodies, and lift up their Heads, and afterward contract their hinder Region, and so bring it forward toward their Heads, and so do gain more ground.

Aristotle, * 1.9 in his Book De Incessu Animalium, addeth a fourth kind of Creeping, acted by various Arches, and doth not essentially differ, from the curled Wavelike Motion, which is managed by a kind of lesser Arches: And the greater Wavelike Motion is full of Wonder in a kind of Silk-worm, which maketh one most eminent Arch, with a most crooked Angle seated in the middle of the Back, highly elevated from the Earth; and other diffe∣rent Silk-worms do make many smaller Incurvations (somewhat aemula∣ting Waves of Water) one Wave impelling another, and receive divers Discriminations of Colours, Shape, and Size: But other Insects, acted with many Wavelike Motions, are most truly denominated Silk-worms, whose Backs are variously acted, with many crooked Arches, being sometimes lifted up, and other times depressed.

So that all slow Motion (wherein the Body is moved part after part, as step by step) is reducible to Four kinds, Spiral, Wavelike, Archlike, and Motion performed by Traction of one part after another, by the help of many Minute Muscles, or Fibres contracting themselves.

And we may take our first rise from the Motion of more perfect Creeping Animals, * 1.10 as being dressed with the better furniture of Organs, found in Eels and Serpents, which are acted with Spiral Motion, consisting of various segments of Circles, having not any recourse into each other in order to a perfect Circle, but somewhat resemble the Circumvolution and Spires of the Intestines, and are not formed by many Bones, Articulations, or Muscles of the Limbs, but by several instruments of Motion, appertaining to the Spine, which is furnished with great variety of minute carved Bones, numerous Joints, and many short Muscles, which do all act their several parts, in the slender Bodies of these long Animals, moved by many lateral Incurvations (where∣in one part is haled after another) displayed in Four several Postures.

The first is that above, celebrated by the Muscles, elevating the Head and Trunk from the Ground, which giveth a prospect of good or ill Acci∣dents, to embrace the one and refuse the other.

The second Posture of Eels and Serpents, * 1.11 in reference to the Motion of Spires, is made by Depression; as by Muscles, by whose Contraction, the Body is inclined downward toward the Ground.

The third Posture of Motion is Lateral, made by the alternate Incurva∣tion of one side after another in forming Spires, which are accomplished by many Lateral Muscles, shortning the parts of the Body, by which it is drawn forward little by little, according to the nature of Motion in Oblong Bodies, resting on many parts of the lower Region, which give so many steps to the total Motion of the Body.

So that the Lateral Motion is produced by the alternate flexions of the Spiral Vertebres, inclined sometimes to the right, and other to the left side, and this Flexion is not made as by the Articulations of more perfect Ani∣mals, according to Angles, but by Arches and Spires, formed by many small Muscles, imparting Tendons to every Vertebre of the Spine, which are bent one after another toward the Head.

So that the many Muscles belonging to several Articulations, being con∣tracted and abbreviated, cannot incurvate the whole Spine, into one great entire Arch; because it would prejudice Motion, if each side should be furnished only with one Muscle, upon whose Contraction the whole side

would be moved with great trouble, while the other resteth, but the side being divided into many Incurvations, is much more readily and nimbly moved, to the great ease and pleasure of those Animals: And some are ap∣propriated particular Muscles to the Head, for the carrying it forward, which is thrust onward not by any other Muscles, but those of the Spine fol∣lowing each other in different sides, and making many small Spires, which by divers Muscular Contractions, do abbreviate the parts of the Body, and carry the Head and Body forward, as being fixed to the Anterior parts of it.

The Local Motion of other more imperfect Animals, is distinguished from those of Eels, Lampreys, Congers, and the like, both in Mode and Instrument of Action; the one being celebrated by small Arches, accom∣panying each other in manner of Waves, and by less perfect organs of Anular Fibres, and small streight Fibres running between, and inserted into them. Whereas Lampreys, Eels, Congers, &c. being more great, strong, and ob∣long Animals, are moved by the mediation of Bones, Joints, and Muscles; but Palmer Worms, and other Insects, are encircled only with many nar∣row thin Membranes, interspersed with many Fibrils, which take their rise from the upper incisure, ending in the next below.

And one difference between Palmer Worms, and other more perfect Creatures (whereupon the first are called Insects) is from many round Lines, encircling the Bodies as with so many Rings (which are worth our remark) as divers Centres of Motion, from and upon which, the Creeping of Insects doth take its rise, and depend; and the Interstices interceeding the Rings, are the proper places of Muscles: So that we may plainly count so many Muscles are there as Spaces running between the Rings, which is evident in every Interstice, when the Palmer Worm moveth its Body, part after part in many Incurvations.

Whereupon it is very probable, that every Muscle lodged between the Spaces, deriveth its origen from the Annular Membrane next the Head, and doth terminate into the Ring immediately following toward the Tail, and the upper Ring (in the motion of every Muscle, is the Hypomoclion) to which it is fastned, which being immoveable, the Muscle contracting it self, shortneth the Space passing between the Rings, and by drawing the lower Ring nearer the upper, pulleth part of the Body toward the Head, which is a step in order to the Creeping Motion of the whole; which is mana∣ged by a Chain of Motion, consisting of many Links, or Rings, tying the Muscles together, which are playing one under another in Successive Motion.

So that in this rare Scene, the upper Machine first moveth, and then the next, and so all the ranks of Muscles seated one under another, do succes∣sively contract and shorten the Interstices of the Rings, whereby they pull the Body forward part by part, as by so many Intermedial steps: So that these ranks of Fibres lodged between the Annular Membranes, do somwhat resemble the Intercostal Muscles (lodged in more perfect Animals) which are like a Teem of Horse, pulling the Ribs one after another, in order to the dilatation of the Thorax, in which the rows of Fibres placed between the Incisure, do differ from the Intercostal Muscles; because they by narrow∣ing the Interstices of the Annular Fibres, do not dilate the inward Cavity of the Muscles, but pull one Incisure nearer another, toward the Head, and by consequence draw gradually all the Body forward. * 1.12

The third kind of Creeping belonging to Insects, is performed by greater Arches, and is that of a kind of Worm, called by the Latines, Geometra,

and may be rendred in English, a Land Measurer; because the Body of this Insect, is raised most eminently in the middle, and is clapped to the Area in both Extreamities, after the manner of a pair of Compasses, which be∣ing joined in both points to the Ground, and afterward removed forward, from one part of the Earth to another, somewhat resembleth the Measu∣ring of Land, and the motion of this rare Insect.

This little Animal doth not make many small Arches in the motion of its Body tending upward like Waves, one following another in various rises of troubled Waters, but formeth one large Arch, made by a single Muscle, taking its rise near the Head, and ending about the Tail; so that the Head being the Center of Motion as immoveable, and the Muscle con∣tracting and shortning it self, draweth the Tail being moveable toward the Head, and so pulleth its Body forward, not part by part, as in Wavelike Motion, but moveth the whole forward at once, made by the contraction of one long Muscle interceding the Head and Tail.

The last and fourth manner of Local Motion in Insects, * 1.13 is accomplished by Traction (as in Worms, Leeches, and the like) wherein the Anterior part of these Minute Animals first march in the Van, in their fore part, and the Po∣sterior bring up the Rear; and the Anterior part is first extended and length∣ned, by being rendred slender, and the hinder part at the same moment is contracted, growing thicker and shorter, wherein it gaineth ground, as being brought forward and nearer to the Head.

The Body of Worms and Leeches, are composed in their Ambient parts, of two sorts of Muscles: The one being Annular Fibres, encircling the Bo∣dy, and are so many Muscles, which being moved, make the Body long and slender; as is very conspicuous, when these Insects of a suddain spin themselves out to a great length and slenderness.

The other Muscles relating to Worms and Leeches, are right and ob∣long, passing between the Rings in their stations, which being Contracted, do shorten the Interstices, and draw the numerous Rings closer to each other, and make the hinder part greater, by pulling them nearer to the Head; whence the Body of these Insects do move, Pian piano, as it is rendred in the Italian Language, little after little, giving great trouble to these tender faint Animals.

Notes

• * 1.1

  Creeping in Reptiles is performed by sweeping their Bellies on the Ground, as having no Legs nor Feet.
• * 1.2

  Reptiles do move their Bodies gradu∣ally, by ma∣king many Arches.
• * 1.3

  Undulation the first kind of motion in Reptiles.
• * 1.4

  The second kind of moti∣on in Reptiles is Fluctuation.
• * 1.5

  The third kind of motion in Reptiles, is made by Ex∣tension and Contraction.
• * 1.6

  The first mo∣tion of Insects is wavelike.
• * 1.7

  The second kind is per∣formed by Spires.
• * 1.8

  The third is effected by Contraction and Extension.
• * 1.9

  The fourth is made by lesser Arches.
• * 1.10

  The motion of Serpents and Eels, is Spiral.
• * 1.11

  The second posture of mo∣tion is made by Depression.
• * 1.12

  The third kind of Cree∣ping Motion is performed by one great Arch.
• * 1.13

  The Fourth manner of Creeping Mo∣tion is per∣formed by Traction.