« السابقةمتابعة »
objects near at hand. In the eye, both these purpose, is so minute as to elude ordinary observacases were to be provided for ; and for the purpose tion. Some very late discoveries, deduced from a of providing for them, a subtile and appropriate laborious and most accurate inspection of the mechanism is introduced:
structure and operation of the organ, seem at length I. In order to exclude excess of light, when it is to have ascertained the mechanical alteration excessive, and to render objects visible under ob- which the parts of the eye undergo. It is found, scurer degrees of it, when no more can be had, that by the action of certain muscles, called the the hole or aperture in the eye, through which the straight muscles, and which action is the most adlight enters, is so formed, as to contract or dilate vantageous that could be imagined for the purpose, itself for the purpose of admitting a greater or less —it is found, I say, that whenever the eye is dinumber of rays at the same time. The chamber rected to a near object, three changes are produced of the eye is a camera obscura, which, when the in it at the same time, all severally contributing light is too small, can enlarge its opening; when to the adjustment required. The cornea, or outertoo strong, can again contract it; and that without most coat of the eye, is rendered more round and any other assistance than that of its own exqui- prominent; the crystalline lens underneath is site machinery. It is farther also, in the human pushed forward; and the axis of vision, as the subject, to be observed, that this hole in the eye depth of the eye is called, is elongated. These which we call the pupil, under all its different di- changes in the eye vary its power over the rays of mensions, retains its exact circular shape. This light in such a manner and degree as to produce is a structure extremely artificial. Let' an artist exactly the effect which is wanted, viz. the formaonly try to execute the same; he will find that his tion of an image upon the retina, whether the threads and strings must be disposed with great rays come to the eye in a state of divergency, consideration and contrivance, to make a circle, which is the case when the object is near to the which shall continually change its diameter, yet eye, or come parallel to one another, which is the preserve its form. This is done in the eye by an case when the object is placed at a distance. Can application of fibres, i. e. of strings, similar, in any thing be more decisive of contrivance than their position and action, to what an artist would this is ? The most secret laws of optics must have and must employ, if he had the same piece of been known to the author of a structure endowed workmanship to perform.
with such a capacity of change. It is as though II. The second difficulty which has been stated, an optician, when he had a nearer object to view, was the suiting of the same organ to the percep should rectify his instrument by putting in another tion of objects that lie near at hand, within a few glass, at the same time drawing out also his tube inches, we will suppose, of the eye, and of objects to a different length. which are placed at a considerable distance from Observe a new-born child first lifting up its eyeit, that, for example, of as many furlongs (I speak lids. What does the opening of the curtain disin both cases of the distance at which distinct cover? The anterior part of two pellucid globes, vision can be exercised.) Now this, according to which, when they come to be examined, are found the principles of optics, that is, according to the to be constructed upon strict optical principles; laws by which the transmission of light is regu- the self-same principles upon which we ourselves lated (and these laws are fixed,) could not be done construct optical instruments. We find them without the organ itself undergoing an alteration, fect for the purpose of forming an image by refracand receiving an adjustment, that might correspond tion; composed of parts executing different offices : with the exigency of the case, that is to say, with one part having fulfilled its office upon the pencil the different inclination to one another under of light, delivering it over to the action of another which the rays of light reached it. Rays issuing part; that to a third, and so onward; the progressfrom points placed at a small distance from the ive action depending for its success upon the nicest eye, and which consequently must enter the eye and minutest adjustment of the parts concerned ; in a spreading or diverging order, cannot, by the yet these parts so in fact adjusted, as to produce, optical instrument in the same state, be brought not by a simple action or effect
, but by a combinato a point, i. e. be made to form an image, in the tion of actions and effects, the result which is ulsame place with rays proceeding from objects situ- timately wanted. And forasmuch as this organ ated at a much greater distance, and which rays would have to operate under different circumarrive at the eye in directions nearly (and physi- stances, with strong degrees of light, and with cally speaking, parallel. It requires a rounder weak degrees, upon near objects, and upon remote lens to do it. The point of concourse behind the ones; and these differences demanded, according lens must fall critically upon the retina, or the vi- to the laws by which the transmission of light is sion is confused; yet, other things remaining the regulated, a corresponding diversity of structure; same, this point, by the immutable properties of that the aperture, for example, through which the light, is carried farther back when the rays proceed light passes, should be larger or less; the lenses from a near object, than when they are sent from rounder or flatter, or that their distance from the one that is remote. A person who was using an tablet, upon which the picture is delineated, should optical instrument, would manage this matter by be shortened or lengthened: this, I say, being the changing, as the occasion required, his lens or his case, and the difficulty to which the eye was to telescope; or by adjusting the distance of his be adapted, we find its several parts capable of glasses with his hand or his screw: but how is it being occasionally changed, and a most artificial to be managed in the eye? What the alteration apparatus provided to produce that change. This was, or in what part of the eye it took place, or by is far beyond the common regulator of a watch, what means it was effected (for if the known laws which requires the touch of a foreign hand to set which govern the refraction of light be maintained, it; but it is not altogether unlike Harrison's consome alteration in the state of the organ there must trivance for making a watch regulate itself, by inbe, ) had long formed a subject of inquiry and con- serting within it a machinery, which, by the artful jecture. The change, though sufficient for the use of the different expansion of metals, preserves
the equability of the motion under all the various y plan varied with the varying exigencies to which temperatures of heat and cold in which the instru- it is to be applied. ment may happen to be placed. The ingenuity There is one property, however, common, 1 of this last contrivance has been justly praised. believe, to all eyes, at least to all which have been Shall, therefore, a structure which differs from it, examined, * namely, that the optic nerve enters chiefly by surpassing it, be accounted no contriv- the bottom of the eye, not in the centre or middle, ance at all? or, if it be a contrivance, that it is but a little on one side; not in the point where without a contriver!
the axis of the eye meets the retina, but between But this, though much, is not the whole: by that point and the nose. The difference which different species of animals the faculty we are de- this makes is, that no part of an object is unperscribing is possessed, in degrees suited to the dif-ceived by both eyes at the same time. ferent range of vision which their mode of life, and In considering vision as achieved by the means of procuring their food, requires. Birds, for in- of an image formed at the bottom of the eye, we stance, in general, procure their food by means of can never reflect without wonder upon the smalltheir beak; and, the distance between the eye and ness, yet correctness of the picture, the subtilty the point of the beak being small, it becomes ne of the touch, the fineness of the lines. A landcessary that they should have the power of seeing scape of five or six square leagues is brought into very near objects distinctly. On the other hand, a space of half an inch diameter; yet the multifrom being often elevated much above the ground, tude of objects which it contains, are all preserved; living in air, and moving through it with great are all discriminated in their magnitudes, positions, velocity, they require, for their safety, as well as figures, colours. The prospect from Hampsteadfor assisting them in descrying their prey, a power hil is compressed into the compass of a sixpence, of seeing at a great distance; a power of which, in yet circumstantially represented. A stage coach, birds of rapine, surprising examples are given. travelling at its ordinary speed for half an hour, The fact accordingly is, that two peculiarities are passes, in the eye, only over one twelfth of an found in the eyes of birds, both tending to facili- inch, yet is this change of place in the image distate the change upon which the adjustment of the tinctly perceived throughout its whole progress; eye to different distances depends. The one is a for it is only by means of that perception that the bony, yet, in most species, a flexible rim or hoop, motion of the coach itself is made sensible to the surrounding the broadest part of the eye ; which, eye. If any thing can abate our admiration of confining the action of the muscles to that part, the smallness of this visual tablet compared with increases the effect of their lateral pressure upon the extent of vision, it is a reflection which the the orb, by which pressure its axis is elongated view of nature leads us, every hour to make, diz. for the purpose of looking at very near objects. that, in the hands of the Creator, great and little The other is an additional muscle, called the mar- are nothing. suprum, to draw, on occasion, the crystalline lens Sturmius held, that the examination of the eye back, and to fit the same eye for the viewing of was a cure for atheism. Besides that conformity very distant objects. By these means, the eyes of to optical principles which its internal constitution birds can pass from one extreme to another of their displays, and which alone amounts to a manifestscale of adjustment, with more ease and readiness ation of intelligence having been exerted in the than the eyes of other animals.
structure; besides this, which forms, no doubt, The eyes of fishes also, compared with those of the leading character of the organ, there is to be terrestrial animals, exhibit certain distinctions of seen, in every thing belonging to it and about it, structure, adapted to their state and element. We an extraordinary degree of care, an anxiety for its have already observed upon the figure of the preservation, due, if we may so speak, to its value crystalline compensating by its roundness the and its tenderness. It is lodged in a strong, deep, density of the medium through which their light bony socket, composed by the junction of seven passes. To which we have to add, that the eyes different bones,t hollowed at their edges. In somo of fish, in their natural and indolent state, appear few species, as that of the coatimondi,the orbit to be adjusted to near objects, in this respect dif- is not bony throughout; but whenever this is the fering from the human eye, as well as those of case, the upper, which is the deficient part, is gup quadrupeds and birds. The ordinary shape of plied by a cartilaginous ligament; a substitution the fish's eye being in a much higher degree con- which shows the same care. Within this socket vex than that of land animals, a corresponding it is imbedded in fat, of all animal substances the difference attends its muscular conformation, viz. best adapted both to its repose and motion. It is that it is throughout calculated for flattening the sheltered by the eye-brows; an arch of hair, eye.
which, like a thatched penthouse, prevents the The iris also in the eyes of fish does not admit sweat and moisture of the forehead from running of contraction. This is a great difference, of down into it. which the probable reason is, that the diminished But it is still better protected by its lid. Of light in water is never too strong for the retina. the superficial parts of the animal frame, I know
In the eel, which has to work its head through none which, in its office and structure, is more sand and gravel, the roughest and harshest sub- deserving of attention than the eyelid. li defends stances, there is placed before the eye, and at the eye; it wipes it; it closes it in sleep. Are some distance from it, a transparent, horny, con- there, in any work of art whatever, purposes more vex case or covering, which, without obstructing evident than those which this organ fulfils
? or an the sight, defends the organ. To such an ani- apparatus for executing those purposes more inial, could any thing be more wanted, or more telligible, more appropriate, or more mechanical ? useful?
Thus, in comparing the eyes of different kinds of animals, we see, in their resemblances and
*The eye of the seal or sea-calf, I understand, is an
exception : Mem. Acad. Paris, 1701, p. 123. distinctions, one general plan laid down, and that | Heister, sect. 69. | Mem. R. Ac. Paris, p. 117.
If it be overlooked by the observer of nature, it brings it back again to its position.* Does not can only be because it is obvious and familiar. this, if any thing can do it, bespeak an artist, This is a tendency to be guarded against. We master of his work, acquainted with his materials pass by the plainest instances, whilst we are ex- “Of a thousand other things," say the French ploring those which are rare and curious: by academicians, "we perceive not the contrivance, which conduct of the understanding we sometimes because we understand them only by the effects, neglect the strongest observations, being taken up of which we know not the causes: but we here with others, which, though more recondite and treat of a machine, all the parts whereof are visiscientific, are, as solid arguments, entitled to much ble: and which need only be looked upon, to disless consideration.
cover the reasons of its motion and action.”+ In order to keep the eye moist and clean, (which In the configuration of the muscle which, qualities are necessary to its brightness and its though placed behind the draws the nictitatuse,) a wash is constantly supplied by a secretion ing membrane over the eye, there is, what the for the purpose; and the superfluous brine is con- authors, just now quoted, deservedly call a marveyed to the nose through a perforation in the vellous mechanism. I suppose this structure to bone as large as a goose-quill
. 'When once the be found in other animals; but, in the memoirs fluid has entered the nose, it spreads itself upon from which this account is taken, it is anatomithe inside of the nostril, and is evaporated by the cally demonstrated only in the cassowary. The current of warm air, which in the course of respi- muscle is passed through a loop formed by anration is continually passing over it. Can any other muscle ; and is there inflected, as if it were pipe or outlet, for carrying off the waste liquor round a pulley. This is a peculiarity; and obfrom a dye-house or a distillery, be more mecha- serve the advantage of it. A single muscle with a nical than this is? It is easily perceived, that the straight tendon, which is the common muscular eye must want moisture: but could the want of form, would have been sufficient, if it had had power the eye generate the gland which produces the to draw far enough. But the contraction, necestear, or bore the hole by which it is discharged, - sary to draw the membrane over the whole eye, a hole through a bone ?
required a longer muscle than could lie straight It is observable that this provision is not found at the bottom of the eye. Therefore, in order to in fish,—the element in which they live supplying have a greater length in a less compass, the cord a constant lotion to the eye.
of the main muscle makes an angle. This, so far, It were, however, injustice to dismiss the eye as answers the end; but, still farther, it makes an a piece of mechanism, without noticing that most angle, not round a fixed pivot, but round a loop exquisite of all contrivances, the nictitating mem- formed by another muscle; which second muscle, brane, which is found in the eyes of birds and of whenever it contracts, of course twitches the first many quadrupeds. Its use is to sweep the eye, muscle at the point of inflection, and thereby aswhich it does in an instant, to spread over it the sists the action designed by both. lachrymal humour; to defend it also from sudden injuries; yet not totally, when drawn upon the pupil, to shut out the light. The commodiousness with which it lies folded up in the upper
One question may possibly have dwelt in the corner of the eye, ready for use and action, and reader's mind during the perusal of these observathe quickness with which it executes its purpose, tions, namely, Why should not the Deity have are properties known and obvious to every ob- given to the animal the faculty of vision at once ? server: but what is equally admirable, though not Why this circuitous perception; the ministry of quite so obvious, is the combination of two kinds so many means; an element provided for the purof substance, muscular and elastic, and of two dif- pose; reflected from opaque substances, refracted ferent kinds of action, by which the motion of through transparent ones; and both according to this membrane is performed. It is not, as in precise laws; then a complex organ, an intricate ordinary cases, by the action of two antagonist and artificial apparatus, in order, by the operation muscles, one pulling forward and the other back of this element, and in conformity with the reward, that a reciprocal change is effected; but it strictions of these laws, to produce an image upon is thus: The membrane itself is an elastic sub- a membrane communicating with the brain ? stance, capable of being drawn out by force like Wherefore all this? Why make the difficulty in a piece of elastic gum, and by its own elasticity order to surmount it? If to perceive objects by returning, when the force is removed, to its former some other mode than that of touch, or objects position. Such being its nature, in order to fit it which lay out of the reach of that sense, were the up for its office, it is connected by a tendon or thing proposed; could not a simple volition of the thread with a muscle in the back part of the eye: Creator have communicated the capacity? Why this tendon or thread, though strong, is so fine as
resort to contrivance, where power is omnipotent? not to obstruct the sight, even when it passes Contrivance, by its very definition and nature, is across it; and the muscle itself, being placed in the refuge of imperfection. To have recourse to the back part of the eye, derives from its situation expedients, implies difficulty, impediments, rethe advantage, not only of being secure, but of straint, defect of power. This question belongs being out of the way; which it would hardly have to the other senses, as well as to sight; to the been in any position that could be assigned to it general functions of animal life, as nutrition, rein the anterior part of the orb, where its function cretion, respiration; to the economy of vegetables; lies. When the muscle behind the eye contracts, and indeed to almost all the operations of nature. the membrane, by means of the communicating The question, therefore, is of very wide extent; thread, is instantly drawn over the fore-part of it. When the muscular contraction (which is a posi
Phil. Trans. 1796. tive, and, most probably, a voluntary effort) ceases Royal Academy of Sciences at Paris, done into English
+ Memoirs for a Natural History of Animals, by the w be exerted, the elasticity alone of the membrane by order of the Royal Society, 1701, page 249.
and amongst other answers which may be given however, both external and internal, is sufficient to it, besides reasons of which probably we are to show that it is an instrument adapted to the reignorant, one answer is this: It is only by the ception of sound ; that is to say, already knowing display of contrivance, that the existence, the that sound consists in pulses of the air, we peragency, the wisdom, of the Deity, could be testi- ceive, in the structure of the ear, a suitableness to fied to his rational creatures. This is the scale by receive impressions from this species of action, which we ascend to all the knowledge of our and to propagate these impressions to the brain. Creator which we possess, so far as it depends For of what does this structure consist ? An exupon the phenomena, or the works of nature. ternal ear (the concha,) calculated, like an earTake away this, and you take away from us trumpet, to catch and collect the pulses of which every subject of observation, and ground of rea we have spoken; in large quadrupeds, turning to soning; I mean as our rational faculties are form- the sound, and possessing a configuration, as well ed at present. Whatever is done, God could have as motion, evidently fitted for the office : of a tube done without the intervention of instruments or which leads into the head, lying at the root of this means; but it is in the construction of instruments, outward ear, the folds and sinuses thereof tending in the choice and adaptation of means, that a crea- 1 and conducting the air towards it: of a thin memtive intelligence is seen. It is this which constitutes i brane, like the pelt of a drum, stretched across the order and beauty of the universe. God, there this passage upon a bony rim: of a chain of movefore, has been pleased to prescribe limits to his able, and infinitely curious, bones, forming a comown power, and to work his ends within those munication, and the only communication that can limits. The general laws of matter have perhaps be observed, between the membrane last mentionthe nature of these limits; its inertia, its re-action; ed and the interior channels and recesses of the the laws which govern the communication of mo- skull: of cavities, similar in shape and form to tion, the refraction and reflection of light, the con- wind instruments of music, being spiral or portions stitution of fluids non-elastic and elastic, the trans- of circles: of the eustachian tube, like the hole in mission of sound through the latter; the laws of a drum, to let the air pass freely into and out of magnetism, of electricity; and probably others, the barrel of the ear, as the covering membrane yet undiscovered. These are general laws; and vibrates, or as the temperature may be altered: the when a particular purpose is to be effected, it is whole labyrinth hewn out of a rock; that is not by making a new law, nor by the suspension wrought into the substance of the hardest bone of of the old ones, nor by making them vind, and the body. This assemblage of connected parts bend, and yield to the occasion (for nature with constitutes together an apparatus, plainly enough great steadiness adheres to and supports them ;) relative to the transmission of sound, or of the imbut it is, as we have seen in the eye, by the inter- pulses received from sound, and only to be lamentposition of an apparatus, corresponding with these ed in not being better understood. laws, and suited to the exigency which results The communication within, formed by the from them, that the purpose is at length attained. small bones of the ear, is, to look upon, more like As we have said, therefore, God prescribes limits what we are accustomed to call machinery, than to his power that he may let in the exercise, and any thing I am acquainted with in animal bodies. thereby exhibit demonstrations of his wisdom. It seems evidently designed to continue towards For then, i. e, such laws and limitations being the sensorium the tremulous motions which are laid down, it is as though one Being should have excited in the membrane of the tympanum, or fixed certain rules; and, if we may so speak, pro- what is better known by the name of the "drum vided certain materials; and, afterward, have com- of the ear.” The compages of bones consists of mitted to another Being, out of these materials, four, which are so disposed, and so hinge upon one and in subordination to these rules, the task of another, as that if the membrane, the drum of the drawing forth a creation: a supposition which evi- ear, vibrate, all the four are put in motion together; dently leaves room, and induces indeed a necessity, and, by the result of their action, work the base for contrivance. Nay, there may be many such of that which is the last in the series, upon an aperagents, and many ranks of these. We do not ture which it closes, and upon which it plays, and advance this as a doctrine either of philosophy or which aperture opens into the tortuous canals that of religion; but we say that the subject may safely lead to the brain. This last bone of the four is be represented under this view, because the Deity, called the stapes. The office of the drum of the acting himself by general laws, will have the same ear is to spread out an extended surface, capable consequences upon our reasoning, as if he had of receiving the impressions of sound, and of being prescribed these laws to another. It has been put by them into a state of vibration. The office raid, that the problem of creation was, "attraction of the stapes is to repeat these vibrations. It is a and matter being given, to make a world out of repeating frigate, stationed more within the line. them;" and, as above explained, this statement From which account of its action may be underperhaps does not convey a false idea.
stood, how the sensation of sound will be excited by any thing which communicates a vibratory
motion to the stapes, though not, as in all ordinary We have made choice of the eye as an instance cases, through the intervention of the membrana upon which to rest the argument of this chapter. tympani. This is done by solid bodies applied to Some single example was to be proposed; and the the bones of the skull, as hy a metal bar holden at eye offered itself under the advantage of admitting one end between the teeth, and touching at tho of a strict comparison with optical instruments. other end a tremulous body. It likewise appears The ear, it is probable, is no less artificially and to be done, in a considerable degree, by the air mechanically adapted to its office, than the eye. itself, even when this membrane, the drúm of the But we know less about it: we do not so well un-ear, is greatly damaged. Either in the natural or derstand the action, the use, or the mutual de- preternatural state of the organ, the use of the pendency, of its internal parts. Its general form, chain of bones is to propagate the impulse in a
direction towards the brain, and to propagate it the most beautiful applications of muscles in the with the advantage of a lever; which advantage body: the mechanism is so simple, and the carieconsists in increasing the force and strength of ty of effects so great." the vibration, and at the same time diminishing
In another volume of the Transactions above the space through which it oscillates; both of referred to, and of the same year, two most curious which changes may augment or facilitate the still cases are related, of persons who retained the deeper action of the auditory nerves.
sense of hearing, not in a perfect, but in a very The benefit of the eustachian tube to the organ, considerable degree, notwithstanding the almost may be made out upon known pneumatic princi- total loss of the membrane we have been describing. ples. Behind the drum of the ear is a second ca- In one of these cases, the use here assigned to vity, or barrel, called the tympanum. The eusta- that membrane, of modifying the impressions of chian tube is a slender pipe, but sufficient for the sound by change of tension, was attempted to be passage of air, leading from this cavity into the supplied by straining the muscles of the outward back part of the mouth. Now, it would not have ear. The external ear,” we are told, “had acdone to have had a vacuum in this cavity; for, in quired a distinct motion upward and backward, that case, the pressure of the atmosphere from which was observable whenever the patient liswithout would have burst the membrane which tened to any thing which he did not distinctly covered it. Nor would it have done to have filled hear; when he was addressed in a whisper, the the cavity with lymph or any other secretion; ear was seen immediately to move; when the tone which would necessarily have obstructed both the of voice was louder, it then remained altogether vibration of the membrane and the play of the motionless." small bones. Nor, lastly, would it have done to It appears probable, from both these cases, that have occupied the space with confined air, be- a collateral, if not principal
, use of the membrane, cause the expansion of that air by heat, or its is to cover and protect the barrel of the ear which contraction by cold, would have distended or re- lies behind it. Both the patients suffered from cold: laxed the covering membrane, in a degree incon-one, a great increase of deafness from catching sistent with the purpose which it was assigned to cold;" the other, “very considerable pain from execute. The only remaining expedient, and that exposure to a stream of cold air.” Bad effects for which the eustachian tube serves, is to open to therefore followed from this cavity being left open this cavity a communication with the external air. to the external air; yet, had the Author of nature In one word; it exactly answers the purpose of shut it up by any other cover, than what was cathe hole in a drum.
pable, by its texture, of receiving vibrations from The membrana tympani itself, likewise, de- sound, and, by its connexion with the interior serves all the examination which can be made of parts, of transmitting those vibrations to the brain, it. It is not found in the ears of fish; which fur- the use of the organ, so far as we can judge, must nishes an additional proof of what indeed is indi- have been entirely obstructed. catel by every thing about it, that it is appropriated to the action of air, or of an elastic medium. It bears an obvious resemblance to the peltor head of a drum, from which it takes its name. It
CHAPTER IV. resembles also a drum-head in this principal pro
Of the Succession of Plants and Animals. perty, that its use depends upon its tension. Tension is the state essential to it. Now we know The generation of the animal no more accounts that, in a drum, the pelt is carried over a hoop, for the contrivance of the eye or ear, than, upon and braced as occasion requires, by the means of the supposition stated in a preceding chapter, the strings attached to its circumference. In the production of a watch by the motion and mechanmembrane of the ear, the same purpose is provided ism of a former watch, would account for the skill for, more simply, but not less mechanically, nor and intention evidenced in the watch, so produced; less successfully, by a different expedient, viz. by than it would account for the disposition of the the end of a bone (the handle of the malleus) wheels, the catching of their teeth, the relation of pressing upon its centre. It is only in very large the several parts of the works to one another, and animals that the texture of this membrane can be to their common end; for the suitableness of their discerned. In the Philosophical Transactions for forms and places to their offices, for their conthe year 1800, (vol. i.) Mr. Everard Home has nexion, their operation, and the useful result of given some curious observations upon the ear, and that operation. I do insist most strenuously upon the drum of the ear of an elephant. He discovered the correctness of this comparison; that it holds in it, what he calls a radiated muscle, that is, as to every mode of specific propagation; and straight muscular fibres, passing along the mem- that whatever was true of the watch, under the brane from the circumference to the centre ; from hypothesis above-mentioned, is true of plants and the bony rim which surrounds it towards the han- animals. dle of the malleus to which the central part is at I. To begin with the fructification of plants. tached. This muscle he supposes to be designed Can it be doubted but that the seed contains a to bring the membrane into unison with different particular organization? Whether a latent plansounds: but then he also discovered, that this tule with the means of temporary nutrition, or muscle itself cannot act unless the membrane be whatever else it be, it encloses an organization drawn to a stretch, and kept in a due state of suited to the germination of a new plant. Has tightness, by what may be called a foreign force, the plant which produced the seed any thing more viz. the action of the muscles of the malleus. Sup to do with that organization, than the watch posing his explanation of the use of the parts to would have had to do with the structure of the be just, our author is well founded in the reflec-watch which was produced in the course of its tion which he makes upon it, "that this mode mechanical movement ? I mean, has it any thing of adapting the ear to different sounds, is one of at all to do with the contrivance? The maker and