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miniature heari With tWo distinet cavities, preSenting appearaneeS aualogous to What are Seen in the adult State . . . . Ainter the Sth dare os incubation, the chich meanwhile increasing in bulli, the head stillretained iis relative large sige, and On Opening it, the cerebrat mass Wasfound to be stili more solid. For the hitherio Separate vesicles Were noWunited, and constituted tWo eminences, containing the ventricles, thethalamus or bed of the Optic nerves, the cerebellum, and the commeneement of the spinal marrOW. . . . The heari pulsated in the usual man-ner, and lungs of a White color Were Seen to have Sprung up beside it. ter the 12th day, . . . the Structure of the lungs Was discernit,te, thelitile ribs Were solidised, and the muscies spread over them eXterually.
When the ldfh My had passed, the chich WaS already nearly perfeci. . . The heart was formed os united ventricles, and a number of arterialtubulos, like sngers on a haud, and whicli previousty were at a distancesto In the hestri, Vere now attached to it immediately. The auricles Were large a d intensely red, and composed os a net ork or plattingos sinewy fibres, in Whicli meshes Or interstices of disserent colors Were perceptible. De Formatione Pulli in ODO.9243. The samo illustrious author having repented his observations,' mahes the following statement respecting the incubated egg.
At the end of 6 hour' . . . the rudiments of the carina and head of he chich were seen RS a Zone,' S imming in a colliquamentum os aleaden color, Which Was bounded by a circle thut served as a Lind of dam . . . . At the end of 12 MurA . . . the carina, defined by whitegones, exhibited the round capitulum or litile head, and also sor thesrst time, beyond iis millille, the orbicular vesicles for sacculi of the
vertebrae, Siluated at intervals On either Side. . . . In Other cicatriculaethus incubated, . . . the carina Of the chieli Was defined by a White gone,
furnished with two processes indieating the rudiments of the head, and had the globules of the vertebrae attached to it at intervals as in theformer case. Ainter the 1 Sth hour, . . . the sollOWing Was the appear-ance of the carina : the head was defined by the white gone, as weli asthe tract of the spine With the sacculi of the vertebrae appended to it.
The treati se, De Formatione Pulli in ovo, is dated February Ι672; thetreatise, De Ovo Incubato, ' is dated october in the Same year. The reader may consult with advantage Μalpighi's Opera Posthuma, Where in his Autobiography pp. I 09, II 0, ed. Amsterdam, I 698 he gives a brief but interesting comment On
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Around the head and necla I more than once saw a gr0wth os flesti, together With the rudiments of the Wings . . . . Ι have Osten remarhed, RS a USual piece of nature's play, a motion present in the gones, by thec0ming and going of Whicli, the areas and cavities of the carina were ei ther enlarged or obliterated. Towarri the end of the Ιεt Jay, the protuberance of the head Was visibie, fas represented in sig. IIJ, and by the mutuat separation os the gones in the bach, a concavity Or grOOVeWas formed in the carina, thereby assording a place sor the spinal
which was at 1irst yello isti, but became SubSequently dUShy red. . . . In the head the eyes mere viSible, . . . the tWo 20nes, united togetheris Ormed various Spaces Or areas, and Surrounded the sive vesicles of thebrain, and the continuous production of the spinal marrow. At thelower extremity of the carina, a dilated angular area assorded a placesor the lo se extended portion of the spinal marrow fluxatre medulloe the sacculi of the vertebrae were in their places as bes ore. At this timethe heari Was clearly discernible. . . . I am stili in doubi as to the priority of the heari or the blood . . . . But thus much is clear, that thestamina of the carina are observed besere incubation ; and asterWards, in the course of incubation, that the vertebrae, and the rudiments of thebrain and spinal marroW, together With the wings and the fleshy cover-ing, are displayed to VieW, While the heari, the vesseis, and the blood stili lie concealed. But when the litile streams appear in the umbilicat area, it is probable that the heart also is appended to the carina, sinceΙ could certainly deieci iis structure besore the 30th hour. Α longintervat however elapses, during Whicli the heari and vesseis are pervaded by an ichor, Whicli at one time is yelloW, then rust-colored, andat last blood red. Whenoe I am inclined to my former conjecture, that the juice, the vesseis, and the hestri, perhaps preeXiSt, and are manifested by degrees, as We ObServe in the Ova of trees.' . . . isbout the 3 6 th hour os incubation, . . . the cicatricula exhibited the umbilicia area
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40 hours the twigs of the vetus had become more evident in the cicatricula, and commencing stom the extreme borderi passed by prolongations into the heari, and the umbilices vesseis arising hom the heari, and forming an angie, gave Osr reticular branches, among Whicli aS yetthere mere not always any distinct large os eis. . . . In the head the USual turgid Vesicles mere seen, representing the brain, and the sirst of
stili larger, and the blood received by the auricle frOm the Vein, Waspropelled through a duci into the right ventricte, and thence throughanother ductJ into the lest ventricte, and at length into the arteries, front whicli it passed into the trunk represented in fig. 324. Fromthis trunk proceeded the umbilicat branches, Whicli terminated in tWigs
capacious than the arteries , occupied the border particularly With a large trunk, the blood running sortii miXed With a yelloWiSh humor. . . . The head Was conspicuousj large beyond the other members. For theeristate cerebrat vesicie, Which Was seen to be divided into tWO paris, was filled with a cinereous and SomeWhat concrete substance : DOt farfroin thenee, in the occiput, at some litile depili, the second, or the vesicle of the cerebellum, Was placed, and to it Was subjoined a portionos the spinal marrOW. In the anterior pari, at a greater depili, lay the
the termination Or apex in front . . .. Νot far from the head the heari protruded Out of the Open thorax, ... iis Structure plainly consiSting of muscular flesti. Τhe umbilicat vesseis issued froin the abdomen, and
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with red blood, while the vein lay below the artery, was narro er thalait, and contained a yellowisti humor. . . . At the end of the 5 fh F. . . . the head Was large, and the cristate cerebrat vesicle Was as repreSented in the figures 37 and 38 , and replete Mili a filamentary substance :to this vesicle was attached the cerebellum. Anteriorly the twO vesicleS of the apex Were seen, With the deeper vesicle placed above them.
the heart was silua ted on iis oulside, composed os a right and lest Ventricte, and of an auricle placed upon the top Of the VentrieteS. . . . Whenthe 8 th Jay had elas*ed, ... the fame vesicular Structure as heretos reWas observed in the brain : the cristate vesicle was furnished With a large Vesset, and the vesicle nexi to it Was concealed, and could not bebrought into viow without denuding and Separating the cerebrum. . . .
and reddor, While of the auricles the right WRS the more QRPRCiOUS. . . . From this time illi the ninth day, the viscera Uere rendered firmer, and the heart nowJ presented iis customary s Orm. . . . Ainter the ninth My. . . the criState veSicles of the brain, whicli terminate in the origins of the Optic nerves, were Amalter and more deeply seated, and inclinedio the fides ; and the Same circumstances mere Observabie in the anterior vesicles. At the base of the brain, Which Was nOW Dearly Solidissed, the folio ing appearances presented themselves. The anterior vesicles Were Seen, and likewise the Origins Of the optic nerves, runningsrom the cristate vesicles to the eyes. A portion of the infundibulum produced from the contiguous vesiele, gave suppori and continuity to the brain; and not sar froni this, the beginning of the spinal marrowWaS Seen depending. . . . On the completion Os the fourteenth Jay, . . .
the lungs were discernit,te inside the body, and of a Whitisti color. . . . . On the followins Jay' est the partS increased in firmneSS. . . . The brain, now solidissed, exhibited on iis upper part the roots of the optic nerves of a diminished sige, the anterior ventricles, the cerebellum, and the beginning of the spinal marrow; and at the base, in ad-
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dition to the paris just mentioned, the infundibulum Was Seen projecting. Aspendiae, repetita8 auctaδque de ovo Incubato Ob8ervation
Such are the observations os Malpighi: but it is to bo noted, that the carina is that finali elongated space Whicli contains the initiament of the head, and the thread-like rudiment of the spinal marrow. Thiscarina Swinas in the white gones, Which lalter proximately surround it, although they somelimes appear to be interrupted or discontinued atthe top. ' But it is necessary that the reader should himself examine Malpighi's figures, and become familiar with the initiat fornis of theliearis of the chich, and with the singular inflections through Whichthey pasS in Succession, besere they coalesce into a single heart. 244. Inasmuch as Some insecis have a number of hearis, and theSehearis are mere VeSicles, and in simplicity os structure bear a certain
resemblance to the primitive heari, it Will, Ι thinh, be tO Our purp0Se, to cite the description os the heart of the silk-Worm and butterfly asgiven by the fame illustrious Author. The heart of the silk-Worm , V he observes, Uis placed longitudinalty in the bach, betWeen the . . . fibres of the muscies, and theliings or tracheat ramifications , Which lalter lie ou each side; and it extends from the very top of the head to the sarther extremity of thebody, so that When the animal is alive, an obscure longitudinal pulsation of the heari is perceived externalty. This heari consists of thin membranes, Whicli are of the fame color as the fluid they enclose, belligat fit si transparent, but asterWards becoming yelloW, and loSing Someportion of their clearness. Whether, in addition to membranes, the
contractions, is a matter beyOnd the information of the senses. Iis figure is extraordinary. In other living creatures the heari is a conicalmass formed os spirat fleshy fibres, ' but in the silk-Worm and creatures of that class it is a single iube, continued froin the tali to the head, and so sar as I have been enabled to observe, With no dilatation orchamber at either end to originate iis motions. . . . This iube iS Widenedand narrowed at distinct intervias, and thus presenis a number of Ovaldilatations continued one into the other; Whieli . . . leads me to Suspectiliat these dilatations are so many corcula or litile hearis, reciprocallyassisting each other. The number of these corcula is considerabie, though Ι have not yet exactly determined it . . . . But it iS probRble . . . that there is one sor each ring, Or at any rate ser each pair Os lungS. . . .
See M alpighi, Appendix de ovo Incubato, fig. 5, 6, 8-13, 17. - Tro' Ex fibris carneis in gyrum deductis.
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from the auricle into the heari, and from the heari into the arterieS. . . . Around the elongated heari, or rather around the severat hearis thebranches of the trachea creep and tWine, so that iis tesser ossseis adhere
closely by their terminat twigs to the membranes of the heari Wherethey lie against the bach, being there visibie on account of the transpa- rency of both the hoari and iis liquid. There is yet another body that
beseis the sursace of the heari, and has ofsseis adhering to the lalter onboth sides; and furthermore, in the severat grooves Or incisures be- tween the rings , where the fleshy fibres terminate or are intercepted, this body exhibiis new trativerse ramifications, So given oss as to presentesmost the appearance of Dur right angies ; Dom Whicli circumstance We may inser, that twO branches are also given osy on each side in this Siluation by the corcula or hearis themselves. There are then a Lind of mucOus ramifications that surround the cardiac iube, by Whicli themUScies also are covered, and the interstices in the viscera beautis ullysilled up; for indeod this body or substance is so abundant, that it more than equais in buth ait the other paris of the silk-worm, the whole
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iis real structure. In Order to throw light upon this pollit, I have und it advisable to recur to the case of other insecis analogous to thesilk-worm. Thus in the larger caterpillars these White ramifications entireb cover the inside of the belly, and beset the viscera therein contained ; and by taking a portion of them out, receiving it in Water, and laying it upon a plece of glass, We shali obtain a rude notion of theircourse and Structure. By this means we find, that they ramisy in themanner Os vesseis, and inosculate With the branches nexi them similarlyramisied, the whole series thus constituting a loose netWork. They areos an oblong shape, a litile depressed, nor do they maintain a uniformbreadth, but in some places are Very narrow comparatively : in Other paris they assume the serm os leaves, then again become narrOW, and ramisting like branches, inosculate and interi ne so as to form a loOSenetWork. . . . Belare the fire this globose' substance melis into Oil and catches flame; where re the salty globules contained in the reticular prolongations, as in membranous Sacculi, may be likened to an Omentum ; and there is reason to docti Whether these are not granaries Ossat, and whether by these means nature does not shew the great solicitudo with which she gathers and holds this olly juice. These omental prolongations are supplied by minute tracheal pipes, Whicli strengthenthem throughout their course. Di ertatio Esistolica de Bombyce, p.
structure as that above described, but the externat color is disserent, and the motion inverse, for the coats of the Severat hearis are noWthichened, and exchange their transparency for a yelloWish hue; thelieari being there re more conspicuous in the butterily than in the Worm. And the motion of the hearis acquired during the sirst days of the existence of the aurelia for chrysalis , stili continues ; that is tosay, the juice is expressed from above d0WnWards, and propelled by
Successive Systole. But nature is by no means So constant in the above
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Very osten aster death a variety of motions are displayed by these
color of the subjacent membranes. Μeanwhile these corcula Uere con-
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stricted in rapid succession both in an upward and downward direction, so that the contained ichor fluctuated under the stroke of these various motioris; and tWo globuleS of sat, adhering to each other and stightly immersed in the humor contained Within the cavlty of the beari, were tossed to and fro, presenting a Singular Spectacle. These globuleS then, when the humor in Whicli they sWam Was expressed by the systole of the heari, vere driveri from below upWards, and frequently returne twith force; but When they happened to stop in the broader pari os oneos the hearis, the Supervening syStole struch them With a most rapidupWard motion, and made them ascend through more than three of the other hearis ; While on the other haud, as osten as they happened tu lodge in the narrow pari, they Were generalty Squeeged toWard the tali by the compression of the systole. Νot seldom during the pulsation of the hearis, these globules exhibited a Whirling motion, and Sometimes even rapidly fluctuated Without mahing any considerable movement either Way. The second observation I made in the chrysalis immodialely after it had been formed. The motions of the hearis Uere
directed Dom the head to the lower pari; then froin the lalter to themiddie ; Dom Whicli the fluid was serit bach by propulsion the opposite way, lihe a hand-bali, to the lail; and this gaine of nature lasted in
245. LANCISI. Ier 6 or 7 hours of incubation, the cicatricula clearly displayed the carina With the rudiments of the chich and the umbilicat vesseis, and also with the circle bounding the colliquamentum. ter 12 houry, the head of the chich appeared in thecarina, and the nodes of the Vertebrae. ter 22 hourg, more or leSS, the umbilicat vesseis Mere increasingly conspicuous. At the end of 28hours, I discovered the heari itself at the fide of the spine, presentingilie appearance and form Os a varicose and semicircular tubule, but it asyet exhibited no sensibie motion. Ainter 34 hourg, I saW the praecordia' stili more clearly, conSiSting not only of the foregoing Semilianar veSSel, but also of certain fibres, Which began to be loosely collected advolvi around it. These rem arks may sussice sor the more rudimentary Structure of the heari and veSSeis, previseus to the appearance of any Sen Sible' Propcordia is a Word used in disserent senses by disserent authors : Lancisi explains that he Uembraces under the term , the heari itself, the pericardium, thegreat vesseis and the muscies to whicli the heari und pericardium are connected. cis. Cit., lib. i., Sec. i. , Prop. i.)- Τr.9
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motion : I Will now state in delati the more internat and beautisul relations that are usualty seen in What is called the punctum saliens affer 40 hour3 of incubation. . . . With regard to the quality of the fluid that flowly traverses the umbilicat vesseis toward the end of the secondday, it is first yellowish, then rust-red, and at last sanguine or blOOdred ; Wherice it is very clear that the more fluid cylinders of colliquamentum, Whicli appear pellucid and persectly limpid bes ore and on thesirst day os incubation, rise through certain gradations Of color, yello isti and rusty red, be re they attain the character of blood; thesechanges being brought about by a gentie fermentation caused by the Warnith, and by the elasticity of the air in motion, the Sulphurous particles meanwhile being disengaged by degrees, and the saline volatile particles raised sto the sursace . With regard to the structure of the
beari, I may observe, that as soon as this Organ begins to exhibit motion, and to deserve the name Os a punctum Saliens, it preSenis a most
beautiful spectacle, but far disserent stom What we find in the persectchich, and in fully formed viviparous animais. Thus it is not os aconical figure utilii aster the pth day. At the end of the 2nd day, therudiment of the heari is seen as a crooked, continuous, yet irregularly constricted and dilated vesset, Which beginning Dom the junction of the umbilicia vetus, or from the vena cava, is first dilated into an ovalvesicie, Whicli is a terwariis to hec me the right auricle; it is then alitile constricted as it goes to constitute the right ventricie, Whicli formsa second dilated vesicle; aster Whicli the canat is narroWed, and thenagain Widened into a third oblong and large vesicie, Whicli ends bybec ming the lest ventricte : this in iis turn operas into the continuousand proportionably narrow trunk of the great artery, Whicli here and there divides into various branches, but more particularly into tWο, whicli ultimately forin the umbilicat arteries. These terminate in areticular plexus at the circumferetice of the cicatricula, and the umbilicia vetus there begin and constitute an orbit of motion in theblood of the scelus, running 1 rom the circumference through the vetusto the praecordia, and stom the praecordia through the arteries tothe circumferetice. But during the time When this rudimentary formand structure are Seen in the heari, or rather in the three hearis Or corcula represented by the three ovat vesicles, the heari itself is not protected by the usual coverings, nor is the breast fortified and enclosed by the ribs and sternum, but it lies open, and the corcula hang out of it, and present themselves to vlew under the form os a bent canal os une- quia calibre, the sections of Whicli are nos as yet combined into one, nor in contact with each other. . . . With respect to the motion and rhythm exhibited in the constriction and dilatation Os the corculum Or