[242] EXERCITATIO DECIMAQUINTA.
Prima ovi inspectio: sive, quid primus incubationis dies in ovo produxerit.

15th exercise
The first inspection of the egg, that is, what the first day of incubation produced in the egg.

UT clarius innotescat, quid prima ab incubatu dies in ovo produxerit; sciendum primo est, quaenam sponte mutationes eo contingant; quibus ovum requietum, a recenti, (citra incubationem) distinguitur; ut ita, quid ab ipso incubitu proficiscatur, sit manifestum.

In order that it becomes clearer what the first day of incubation produced in the egg, first of all we have to know what changes spontaneously happen, according to what things a not fresh egg differs (independently from incubation) from a recent one, so that it becomes evident what originates from the incubation itself.

Cavitas igitur, ut diximus, in obtusa ovi parte, omnibus quidem adest; sed quo vetustius ovum fuerit, eo maior indies redditur; praesertim locis et temporibus calidioribus, exhalante nimirum parte aliqua albuminis tenuiore; ut in historia ovi dictum est. Eademque, dum ampliatur, magis secundum ovi longitudinem, quam latitudinem expanditur; et figuram demum ab orbiculari declinantem obtinet.

Therefore in all the eggs is present a cavity, as I said, in the obtuse part of the egg, but how much the egg is old as much the cavity becomes greater with the passing of the days, especially in warmer places and seasons, without doubt since some slimmer part of the albumen evaporates, as it has been told in the description of the egg. And, while becoming larger, it more expands according to the length rather than the width of the egg, and finally it assumes a shape straying from the circular one.

Cortex ovi, minus iam transparens, offuscatur.

The eggshell, already less transparent, becomes clouded.

Albumen crassius redditur et viscidius; ad stramineum sive spiceum colorem vergens.

The albumen becomes thicker and more viscid, verging to the color of the straw or of the spikes.

Propria vitelli tunica, laxior reddita, in rugas flaccescit: nam et huius liquoris aliquid tempore dissipari verisimile est.

The proper tunic of the yolk, having become looser, gets flabby and rises in wrinkles: in fact it is likely that passing the time also a little bit of this liquid is dispersed.

Grandines eodem semper loco, positura, et consistentia, in utraque ovi extremitate reperiuntur (idque tam in ovis recentibus, quam requietis; tam per coitum conceptis, quam subventaneis); quarum firma copula vitellus cum albumine connectitur, et uterque liquor debitam invicem positionem servat. Sunt enim duo mutuo opposita stabilimenta, sive poli et cardines [243] huius microcosmi; ea arte fabrefacti, quasi albuminum essent numerosae tunicae, forentque hinc inde in utroque extremo simul contortae in chordam nodosam, qua vitello adnectuntur. Indeque fit, ut vitellus aegre ab albumine secedat, nisi prius chalazae, aut cultello recissae, aut manu abruptae fuerint; quo facto, protinus ad invicem separantur. Scilicet horum cardinum ope, vitellus tum in ovi centro firmatur, tum in debita sui consistentia conservatur. Adeo ut praecipua pars, cicatricula nempe eandem ovi regionem (ceu altitudinem) respiciat, et in media ab utroque cacumine distantia permaneat. Quippe macula haec sive cicatricula, tam in requieto ovo, quam recenti, eadem consistentia, magnitudine, et colore, eodemque situ exstructa, cernitur. Quamprimum autem a gallinae incubantis fotu, vel alterius cuiuspiam blandi caloris accessu, ovum ad pullulationem mutari incipit; macula haec dilatatur illico, oculique pupillae instar explicatur; indeque (ceu praecipuo ovi centro) latitans plastica vis prorumpit et germinat. Haec tamen prima pulli origo a nemine hactenus, quod sciam, observata est.

The chalazae are always found in the same point, with the same disposition and consistence, in both the extremities of the egg (and this happens in both recent and less recent eggs, both conceived through the coition and sterile), and the yolk joins to the albumen thanks to their strong bond, and both liquids keep their proper mutual position. In fact they are two supports opposing each other, that is, pins and hinges of this microcosm, built with such an art as being numerous tunics of the albumens, and as being at both the extremities twisted together from one side to other in a knotty rope, thanks to which they connect to the yolk. From this it comes that the yolk hardly separates from the albumen, unless the chalazae have been previously cut with a knife or broken with the hand; after this has been done, they immediately separate each other. It is evident that for the action of these hinges the yolk is both maintained at the center of the egg and preserved in its proper consistence. So that the principal part, that is, the cicatricle, occupies the same position (or height) of the egg and remains at a distance located in the middle among the two poles. Really this patch or cicatricle, both in not fresh and in fresh egg, appears of the same consistence, size and color, as well as placed in the same point. But as soon as possible the egg starts to modify in order to produce the chick because of the heat of the brooding hen or for an increase of any other mild heat. Immediately this patch dilates and expands as a pupil of the eye, and from this point (or principal center of the egg) the hidden and modelling force breaks out and makes to bud. Nevertheless, as far as I know, till now this first phase of the origin of the chick has never been observed by somebody.

Secundo itaque incubationis die, postquam ovum horas viginti quatuor sub gallina tepuit; ut cavitas eius in obtuso cacumine multum ampliatur et descendit, ita interior quoque ovi constitutio permutari incipit. Vitellus nempe, qui prius in albuminis centro haerebat, versus cacumen obtusum assurgit; eiusque pars media, cui macula infixa est, attollitur, et membranae cavitatem ambienti sese applicat; adeo ut vitellus cavitati per cicatriculam coniungi videatur; et prout vitellus ascendit, albuminis pars crassior tantundem in acutum imumve angulum detruditur. Unde apparet, ut recte Fabricius observavit, vel errasse Aristotelem[1], vel mendum in codice esse, cum dicitur: Effertur per id tempus (nempe intra dies tres totidemque noctes) luteus humor ad cacumen, qua ovi principium est, atque ovum [244] detegitur ea parte, scilicet ob cavitatem dilatatam. Appellat autem Aristoteles[2] principium ovi, acutam eius partem, quae posterius exit. At certum est, vitellum ad obtusam ovi partem assurgere, cavitatemque ibidem dilatari. Certe erravit Aldrovandus, qui, tanquam expertus, asserit, vitellum ad acutam ovi partem efferri. Vidi aliquando, fateor, secundo et tertio die, cicatriculam dilatatam, pullique iam positum exordium, necdum tamen ascendente vitello; raro autem id contingit; et ab ovi imbecillitate profectum arbitrabar.

Therefore at the second day of incubation, after the egg warmed up for 24 hours under the hen, so as its cavity in the obtuse pole increases quite a lot and goes down, as many also the inside structure of the egg starts to change. In fact the yolk, before sticking to the center of the albumen, raises toward the obtuse pole, and its middle part, to which the patch is fixed, lifts and joins the membrane surrounding the cavity, so that the yolk seems join the cavity by way of the cicatricle, and so as the yolk raises, as many the thicker part of the albumen goes down in the acute or low corner. Therefore, as rightly Fabrizi observed, it seems that Aristotle is mistaken, or that in the code an error is present, when it is said: «During this space of time (that is, within three days and as many nights) the yellow liquid moves toward the apex, where is the principle of the egg, and the egg exposes itself with that part» that is, because of the enlarged cavity. Really Aristotle calls «principle of the egg its acute part going out last». But it is certain that the yolk raises toward the obtuse part of the egg and that still here the cavity enlarges. Aldrovandi certainly has been wrong, who, as being experienced, affirms that the yolk moves toward the acute part of the egg. I acknowledge that sometimes I have seen the cicatricle widened in second and third day, and that there already was the beginning of the chick, without nevertheless the yolk raising; actually this seldom happens and I thought that it was coming from the precariousness of the egg.

Secundo incubationis, sive primo inspectionis die, dicta macula dilatatur ad pisi vel lentis magnitudinem; et in circulos (ceu circino circumductos) dispertitur; qui punctum album perexiguum habent pro centro. Hanc maculam Aldrovandum quoque observasse, verisimile est; siquidem ait, in medio lutei quasi subalbidum quid apparuisse, cuius Aristoteles non meminit: et Coiterum, ubi ait, secunda die in vitelli medio pars candidior reliqua: atque etiam Parisanum, cum ait, secunda die album corpus mediocris grani lentis magnitudinem et figuram repraesentans conspici: estque illud, inquit, galli semen alba et tenuissima tunica obductum, quod substat duabus communibus toti ovo membranis; superstat vero propriae vitelli tunicae. Crediderim tamen, neminem hactenus cicatriculam hanc in omni ovo reperiri, pullique originem esse, agnovisse.

In the second day of incubation, that is, in the first day of inspection, the above-mentioned patch dilates up to reach the size of a pea or of a lentil and subdivides into circles (as if traced by a compass) having as center a very small white point. It is likely that also Aldrovandi observed this patch, since he says «in the center of the yellow something almost whitish appeared, which Aristotle doesn't mention» and Coiter when says «at the second day in the center of the yolk a part clearer than the remaining». And also Parisano, when says: «The second day I have seen a white formation endowed with the dimensions and the shape of a lentil of middle size, and it (he says) is the semen of the cock covered by a white and very thin tunic, and it is located under the two membranes common to the whole egg, but it is located above the tunic proper of the yolk.» Nevertheless I believe that till now nobody knew that this cicatricle is found in every egg and that it is the origin of the chick.

Interea chalazas sive grandines, hinc atque illinc ab utroque ovi cacumine, versus latera eius declinasse videas: idque ob permutatum illum, quem diximus, liquorum situm. Adeo ut altera chalaza ex obtuso angulo aliquantulum descendat, altera vero ex acuto cacumine tantundem sursum feratur: quemadmodum in obliqua sphaera, quantum alter polus supra horizontem ascendit, tantundem alter deprimitur.

In the meantime you can see that the chalazae or hails on one side and the other from both apexes of the egg are moved toward its sides, and this because that change of location of the liquids about which I have spoken. So that one of the two chalazae goes down a little bit from the obtuse corner, while the other one moves as many aloft starting from the acute corner, so as in an oblique sphere a pole climbs above the horizon as much as the other one goes down.

[245] Vitellus etiam (praesertim ubi cicatricula est) paululum colliquescere incipit, propriamque suam tunicam (quam ante incubationem in ovis requietis laxiorem et rugosam diximus) in tumorem attollit; videturque eundem colorem, consistentiam, et saporis bonitatem, quam in recenti ovo habuit, recuperasse.

Also the yolk (above all where the cicatricle is located) starts to liquefy a little bit and makes swollen its tunic (which before the incubation in the not fresh eggs I said to be rather loose and rough) and it seems that it recovered the same color, consistence and tastiness of the taste it possessed in the just laid egg.

Est hic primae diei processus ovi ad prolem, primumque advenientis pulli vestigium. Aldrovandus addit, albumen necdum alterari; quod veritati consonum est. Dum autem affirmat, galli semen in eodem deprehendi, manifesto fallitur. Levissimo nempe argumento innixus, putavit chalazas esse semen galli, quia scilicet ova, iis destituta; infoecunda sunt. Ita sane; et ne ova quidem: siquidem irritis, pariter ac foecundis, grandines semper adsunt. Ille vero, forsan a mulierculis deceptus, quae illas in Italia galladuram vocant, communem errorem sequutus est. Nec minoris imprudentiae Hieronymus Fabricius tenetur, qui, sculptis pluribus imaginibus, formationem pulli exhibet; eumque ex chalazis corporari contendit: non animadvertens, grandines iis temporibus integras utrinque, et immutatas (sed loco motas) reperiri; pullique exordium alibi, remote a chalazis, quaerendum esse.

This is the evolution of the first day of the egg to produce the offspring and the first trace of the coming chick. Aldrovandi adds that the albumen is not yet changing, which corresponds to the truth. But when he affirms that «still in the albumen the semen of the cock is seen», he is clearly wrong. In fact basing himself on a very weak test he believed that the chalazae are the semen of the cock «since just the eggs lacking in them are infertile». He writes quite this way, and certainly they are not eggs: since the chalazae are always presents both in sterile and in fertile eggs. But he, deceived by the silly women in Italy calling galladura the chalazae, perhaps followed a common mistake. Nor Girolamo Fabrizi is judged less careless who, through the execution of numerous images, show the formation of the chick and affirms that it takes body from the chalazae, without realizing that in those moments the chalazae are found intact on both sides and identical (but moved of position), and that the beginning of the chick has to be sought in another point, far from the chalazae.