The economy of the animal kingdom, considered anatomically, physically, and philosophically

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need of somo common regulator to govern both the larynx and pharynx, and Which Wheu Once acted upon necording to tho fluxion os iis fibres, may itself aci usi thout any previOUS eXercise of the Will, or may afterWard promoto the performatice of the voluntary aut SpontaneOUSJy. For the actions Os mastication, deglutilion, and sorWarding the laod, are ali in One line Os progreSSion, Since one may come aster the other, One may exist audbe performed With or Without the other; and sor euch particular Operation there re particular nerves are required, and alSO RWOnderfui connection Or communication belWeen them. Butthe actions os speining and modulating in the Same organ mo- disying itsed and articulating, concur With the actions abOVementioned, Whicli there re require their OWΠ nerve, their OWn nervolis fascicles of the fame, and their OWn particular plexus. Hence, ns nil these things concur in the tongue, there is need os sume generat regulator to govern the laryΠX and pharynX, Iest the oesophagus Ahould exercise the aut of sWallowing at tho Samo moment in Whicli the trachen is respiring ; OtherWise thesimultaneous and distinet action of the nerves of the fifth, eighth, and ninth pairs upon the muscies of the longiae, Mould be im- pedest, as also the distinet action of the muscies of the os hy-oides, Iarynx and pharynX. Henee When the CeSophaguS RCtS, the Stomachio plexus and par vagum On both sides act also uponthe recurrent nerve; and this upon the superior branch Witti Whiel, it is connected by anastomosos in the scuti form cartilage

and thyroid gland; and thus tho larynx is closed, and the lunges cense to respire. But When the larynx acts With the lungs, thepar Vagum comes into play, and likeWise the highest cervical ganglion Os the intercostat nervo; the motion of both of Whichis the One universat motion, Or the motion of the brains syn- chronous With that of the lungs, by means of Whicli the pharynxand oesophagus are alternately closed. And for this end, theoesophagus is lied up to the larynx and trachea, and at the fame time passes through the diaphragm in company With the par Vagum, test One Should net simultaneousty With the other, thetongiae acting in conjunction With it by means Of a communication belWeen the nerves. The case uould be OtherWise Were there One organ lar mastication, and another disserent organ lar Speech. In the meantime, the process of mastication can be performed

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Separalely Doui that os deglutilion, and simultaneousty With thatos respiration ; a passage for the uir being provided through thenOStriis. The case is not the sume, hoWever, in regard to deglutition. From What has been statvd Wo may infer, that thegenerat motion of the stomach derives iis origin in some meaSuresrom Voluntary aetion, as Of the chelli, longue, throas, pharynX; of the laod thrown tuto the oesophagus through the medium ofthe smaller portion of the par vagum and the Spinal acceSSOryΠerVe; and then asterWarils becomes spontaneous through themedium of the large portion Of the Same par Vagum. There is again another Origin of the peristallio motion Of the stomach, Whicli has also iis subordinate special and particular motions; for the par vagum is continuest by iis plexuses into the intestines,as the duodenum, jejunum, and ilium, and in Some mensure into the caecum, colon and rectum; but Dom the colon a mixed voluntary motion begius, for the Sahe of carrying the excretions forWariis. The par Vagum is continued also into the mesente , livor, and gall-bladder, and in Some mensure tuto the kidneys, over nil Whicli the motion of the stomach presides. 497. Among these severat motions, Whicli are nil under tho regulation of the par vagum, and subjected to the one most universat motion, We may enumerate that Of the heari, Whichmay be called a universat inserior motion, sor it has under itthe Whole arteriai and venous system Os the body. But in ordor that in these continuous vesseis, the fluent Wave, agitated by different motioris, may perform iis perpetuat circle amid such auimmense variety of Operations, it is most Wisely provided, thalench vesset, as Woli as the hestri itself, and the larger arteries and vetus, 11ay, the very least, Shali have ossseis of the par vagumund intercostat nerve sent into it, so that these Ossseis are thechios a genis in the viscera, and regard everything only as the progeny of their oWn fibre. Where re, When the nerves thias produce their motions, they govern each Vesset conformably to the motion, and While they reduce it to the motion of the beari, they reduce it at last to the universat motion of the bratris. OtherWise the Wave Would Dam ut the mouit, of every VesSel, charybdic Whiripo ls Would arise ali Over, and nil communications Would be intercepted; under Whicli circumstances theorders of ali things Would be deranged, their connections Would

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498. And into the cause of the action of the si eat cardiacplewu' and the nerves that depend Uon it, sarticular0. On this Subjeci See the wOrtis On anatomy, passim. But Ι cannot gi Vea better description than that elaborate one of Vietissens, in hi SNeuroyraphia Universalis, fab. xxiii. This plato exhibiis the true cardiae nerves, With the greater and lessor plexuses, thoughtheSe not SO clearly as Wo could Wish,) unu also the intercostalnerVe, and the par vagum; and I have transferred it to my Workas a beautiful exposition Os our present doctrine. But the plates Os other authors also, and particularly of Lancisi, De Motu Cordi' kc., tab. i. iv. Vii., deServe to be caresully consulted, RSthey SheW the nerves of the posterior part of the heari, and particularly those that invest the coronary vesseis. Vith the plate of Vieussens We ought to beeomo familiar, in ordor that theseverat clauses that follow on the motion of the heari, may beclearly understOOd. FOr this reason, I shali give the description of these nerves presented in the plate, WOrd sor Word Dom

499. In this plate, then, Κ indicatos the anterior region of the heari, denuded of the poricardium and of the sanguiferous ducis. I. the right auricie. M the lest auricle. Ν the descend-ing cava cui Osr near the right auricle. O the ascending cava cui oss a littio above the diaphragm. Ρ the pulmonary arterycut Osr near iis origin. O. Q tho trunk of the vorta dividen into

os the ascending trunk of tho aorta. X tho tost branch of thosame, Whicli immediately divides into tWo Amuller branches, the interior and tesser of Which, Y, is tho test carotid artery; theexterior ends in the lest vertebrat artery Z, and in the lest axit Iary artery. O the descending trunk of the aorta cui oss. Τthe origin of the right vertebrat artery cut OT V the right ax-

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os nerves, With iis gangliosorm plexuses on the lest fide. Ε, Η, Ι, the fame With the samo On the right Side. α, V, Δ, V, 37,&c., the intercostat nerve With iis gangliosorm plexuses On thelest Side. a, a, u, V, 37, the fame With tho fame on the right Side. Δ , 30, a fibre arising Dom the superior cervical gangliO-form plexus of the lest inter Ostia nerve, Whicli communicateS

runs doWn to the anterior portion of the pericardium, and is distributed through it. V the inferior cervical gangliosormplexus os the right intercostat nerve. 34, a litile branch arisingsrom this plexus, Whicli runs doWn and per rates the pericardium ; and then, after having received a litile nerve proceedingsrom the superior cardiac plexus, Sends a fibril, 35, to the conis of the aorta, and passing over the trunk of the pulmonary artery,

spliis into the fibriis 36, 36, 36, kc., that supply the front of thelieart. 5, a branch Dom the right trian k of the eighth patri that sends a fibre, 6, to the coats of the aorta. 5, 8, a fibre of the same branch, terminating in the superior cardiac plexus. 8, 9, 10, the trunk of branch 5, of Whicli 10 is sent to the right portion of the peri cardium Occiapying the posterior region of the heart. Τhe ossset 9, 11, 12, 12, runs like a girdie round the de- Seending Vena caVM Where it opens into the upper part of the right auriete, and terminates on the cava after sending the fibriis 12, 12, I 2, to the right auricle. 14, a tWig hom the right nerve of tho dighth pair distributed through the right auricle. 39, 39, tWo smali branches coming Dom the loWest part of the thoracic gangliosorm plexus of the lest intercostat nervo, of vhicli theupper gives Oss three fibriis, Whereos the upper 40, 40, here cutori are distributed over the insophagus and trachea; but thethird, 42, unites With the lest nerve of the eighth pair. Thebranches 39, 39, are ut last deflected toWard the middie regionof the breust, and when they come to the back of the aorta, divide into severat intercommunicating tWigs, and together Withfibres Dom the eighth pair, With Whicli they interWeave, formille great nervous plexus 43. y, a branch of the lest nerve of the eighth pair, Which besides producing the lest recurrent neTV Sends a fibre, Z, to the superior cardiac plexus, and a sibye, 2, to the heari and Iest auricle. 43, the superior cardiac plexus, Whieb

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is much larger than the inserior. 47, 47, tWigs proceeding Domthe superior cardiae plexus, and supplied to the coats of thenorta. 49, tWo tWigS proceeding also froin the lower part of the Superior cardiae pleXus, and coalescing, and Which giving a fibril, 50, to the coats of the storta, produce the inferior cardine plexus, 5 I, and at length by their extremities, 52, surround the

ing Dom the right si de of the superior cardiac plexus, Whicli coalesces With a litile branch, 34, and with it supplies the frontos tho heart. 45, 45, 45, fibriis Dom the fame cardiae pleXUS, which liko tho fibrils, 44, 44, are seen cut Oss, and are Spent Onthe pericardium. 46, a fibro Dom the lest fide of the superior cardiae plexus, Whicli coalesces With fibre 2 of branch y. 53, alitile branch Doui the superior cardiae plexus, Whieli is distributed over the lest auricle of the heari, and joius the tWig 4 of fibro 2. 4 a tWig of fibre 2, distributed over the lest auriclo. 3 a tWig of fibro 2, distributed over the front of the heari,about iis test fide. 44, 44, 44, 44, fibriis Dom both sides of the Superior cardiae plexus, Whicli are distributed through tho internat part of the Iobes of the lungs, and tho glaniis set in theirupper pari belliud the trachea. 13, 13, 13, 13, branches of the eighth patri Whose oflaeis, here cui Osr, form by their interlace-ment the pneumonic plexuses. 15, 15, 15, tWigs of the eighthpair of the lest fide, Whicli are spent partly on the coats of the insophagus, and partly on the heart. 500. But it is to be observed, that ouly the larger cardiac

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Superior cava, nos o ly to the right auricle and ventricte, butalso to the plexus ab ovo alluded toV u. 463, p. 434). Τhis illus

tri Ous author describes also unother ploxus disserent froin that mentioned by Vieussens. Α largo plexus, SVs he, . . . lieSposteriorly in the base of the lipari, betWeen the pulmonary artery and the aorta, just in faet Where the ductus arteriosuS paSSeSbetWeen those two great vesseis. This plexus mortis the moSt particular attention. For a multitude os nervos Dom oncti Osthe sive patrs concurs to produce it, and it again gives Oss innumerable nervous filuments to the inuer substance of the heart.

ptate of Vieussens, lies betWeen the norin and trachea, and thele88er plexus belWeen the pulmonary artery and the lest auricle. ut tot us kosep to the nerves figured by Vieussens, test by goingbeyond them We obscure What is ulready clear. With respeet tothese We nre to notice, I. That the nervos of the right auricluari se principalty Dom the par vagum of the right fide, but notlikoWise Doni the intercostat norve, nor immediately Dom thegrent cardine plexus. 2. That the nerves of the lest auricle also

nimost ali the cardiae nervos rm gones round the great orifices of the heari, as ut the entrance from the superior cava into theright auricle 12, 12, 12, and froin the right auricle into the right ventricte 36, 36, 36, 36: Dom the pulmonary vein into the lest

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vice versa; sor did both seis of nerves depend upon the fame Origin os motiou, then at the Same moment they WOuid strationtho fibros and the tuuies of the vesself themselves, and compelthem to perform the Same reciprocations. This cannot be botterseon than Dom Lancisi, O . Cit., tab. i. iv. vii.,) Who traced thecardiac nerves With an espectat VieW to ascertain What nerves are Supplied to the coronary vesseis, and the course of these he hasmost accurately investigated. It is Worthy of rem arti, I. Τhat the nerves Whicli command the coronary arteries so called, descend principalty Dom the uppermost ganglion of the lest inter-

and penetrating the pericardium besides tho os et that it sonds

nary artery on the bacii part of the same) is immediately ius octod Whon it comes in contact With the pulmonary artery, and like a neW stav binds doWn the trutili of the norta, Where it is attached internalty to the pericardium; and then beeomes recurrent to the trachen and oesophagus n. 463, p. 434, 435). The

11OrVes that . . . are distributed Over the posterior sursace of thelieari , run at the Side of the norta. . . . They entWine the trutilis and branches of the coronary arteries, as ivy Wrenthes iis claSpsaround the trutilis of troes : and indeed they strengthen and invest the arteries as it Were With litile nerVOHS Shenti, S. . . . Andhere We have observed, nos Without admiration, that tho littio nerves that accompany and invest the smali arteries, are insertodand penetrate chiesty at the paris Where the lalter are strength

that ali tho nervous tWigs sent to these arteries, ariSe immedi-utoly Dom the intercostat nerve; While the Othors, that enter into the muscular substanee, proceed Dom another Origin, and srst indeod sorm gones or belis, as it Were circular StVS, around the orifices, and Dom Which tWigs proceed. 2. But thOSe nerves that run to the proper arteries and vetus Of the auricles, Lancisi

has not delinented, but Vieussens in his plate has represententWο, 14 and 53, Whicli do uot procoed frOm the gones, aud

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Whicli, We may conjecture, pass into the above vesseis; and SOenable them to perform their diastole When the auricle performSitS Systole, and vice versa. 3. The coronary Veius so called aregoVerned by the nerves that are collected in the substance of thelieari, and afterWariis run to the vetus, accompanying their branches; as appears hom this observation os Lancisi: A sar larger quantity of nerves,V says he, is supplied to the coronaryarteries, than to the accompanying Veius. . . . In the Vein S theyRpsear to creep along, and to beeome as it Were reflected Domthe apex to tho base, While in the arteries, as he states, they are adherent Dom tho base to the apex.V) . . . With respect to the

that when the heari sWelis up, the nerves are draWΠ upon by theSetheir boundarios fixed in the substance of the lipari, and thus that the vesseis are Contracted, and urged to expel their blood. Like-Wise also the coronary arteries, by their fixen boundaries betweenthe aorta and pulmonary artery, and the ventricles; for the ner-vOus Stays designest for the coronary arteries, and for the coronaryVeins, sarteries and vetus that discliarge themselves into theaorta and into the right auriclo,) cannot have the fame localities, because the auricle associates With the ventricles in One Way, and the storta and pulmonary artery in another; the former Superinduces itself upon the ventricle in the manner Of a fringe Orcrest, While the latior is continuous With the ventricies; so that the Origin Of the nerves for the so-callud vetus must be froin themuscular substance of the heari, and the origin for the so-called arteries must be in the confine belWeen the noria Or pulmonaryartery and the Ventricles, in Ordor that tho systole os ali thesemay coincide With the diastole of the ventricles, and vice versa n. 423, seqq.). But ali the nerves thus brought in, depend onthe generat motion of the hestri; and the more manifestin as itis plain that these vesseis are continuous With the tendous of the

502. And moreover into the cause of the action of the musci ;for the heari in ali respecis is a musole. Everything in the animal machino that lives by acting, is furnished With a motivo si bre, Whicli is What acis, and iis fluid is What livos; and as in tho

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soster paris there is nothing but lives, and nothing but adis, itfollows, that a motive fibre of some Liud is the main constituent of tho body. And is anything seems to have ceased to live, astho indurated tendinous or ossis ed paris of a musese, stili experiouce shoWs that in iis sirst infancy it consisted of motive fibros. Nevertheless, the paris that have thus become indurated, havetheir OWn cause; for they perform a generat cause in the fame place, Where Originalty, and When they Were in distinct fibros, they performed every particular cause. Since then the motive fibre rules everyWhere in the machine that lives by acting, sothe Doctrine of the Motive Fibro holds a principat place in the science of the animal economy, and requires a tengthy Pari tobe devoted to it. But as I do not here prosess to treat of the subjeci, Ι Will merely state principies almost unaccompanted by experience, although reatly deducen Dom it. Yet since there is more Weight in one faci than a thousand reasonings, I Will letlaci plead iis oWn causo in the Ρart above alluden to.

Second0. In ordor that this fluid may live by acting, it is necessary that it be in a fibro, by Whicli it may be distinctly determinud : there re there is nothing that, as an essicient cause, truly produces action, except the fibre With this iis fluid. Othor vesseis, With their enclosed suid, Which may be called derivod fibres, aut only so sar as they rightly and determinately containthis fibro. On this subject also We have osten spOhen above

Third . There are as many distinet degrees of motive fibrosas there are os fluids in the vesseis, one of Whicli fibres is sub- ordinate to another, just as the causate is subordinate to iis

cause. Therelare the frat, or primitive motive fibre, is the very fibro that in the brain is callud the medullary fibre, but in thobody, the nervous fibre. The secon Whicli is derived Dom thesrst, is the vesset of the purer or White bl ood, or the fibro thatis constituted of those former vesseis, and is called in general

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upon the compotand fibres and their fluid; and vice versa, thesuid of the compound shre can aut upon the simple fibre undiis suid: thus there is action and reaction, Without Whicli noreciprocul motion, Auch as We find in the muscies, can exist nudsubsist. Hence the nervous fibre, by means of iis fluid, cannot upon the vesset and iis bio id, and the vesset, by means ofits blood, can net upon the nervous fibro and iis fluid; givingbirth to action and reaction, Without vhich the muscle cannot reciprocate iis motions. Hence the simple fibre can act uponthe vesset of the purer blood, and vice versa; as in minute ani-mnicula Or insecis, and in the litile membranes Or Other paris of the largor animais, Where nil things are White, and yet most active. And heiace the simple fibro, by means of the vesset os the purer blood, can aut upon the vesset of the red blood, and vice veraa, RS appears in ali the seshy muscies; Whicli, When