[278] EXERCITATIO VIGESIMATERTIA.
De pulli exclusione; sive partu ex ovo.

23rd exercise
The exclusion of the chick or the birth from the egg

EST ovum, ut diximus, quasi uterus expositus, et locus in quo foetus formatur: matricis enim munus obit, pullumque ad debitum nascendi tempus amplectitur: qui perfectus iam inde paritur. Ovipara itaque non discriminantur a viviparis, quod haec foetus suos vivos pariant, illa non item; pullus enim intra ovum non solum vivit, et movetur, sed respirat etiam, ac vocem edit, vitaque iam natus perfectiore fruitur, quam reliquorum animalium foetus: sed differunt potissimum generationis modo; quod nempe in viviparis, uterus sive locus [279] in quo foetus formatur, sit intra animal, cuius calore fovetur et perficitur; in oviparis vero, ovum ceu uterus extra animal exponitur; quod tamen illud non minus incubando fovet, quam si intra corpus suum amplecteretur.

As I said, the egg is almost an external uterus and the place where the fetus grows up. In fact it acts as an uterus and embraces the chick until the exact moment to be born, and when completed then it is begot. Therefore the oviparous animals don't distinguish themselves from the viviparous ones since these give birth to their living fetuses and those don't do the same. In fact the chick not only lives and stirs inside the egg, but also breathes and sends forth a voice, and after it is born it enjoys of a more perfect life in comparison to the fetuses of the other animals. But they differ above all for the manner they are produced, since precisely in the viviparous animals the uterus, that is, the place where the fetus grows up, is located inside the animal by whose heat it is heated and completed, while in the oviparous animals the egg, that is the uterus, is outside of the animal, but however the latter by the incubation heats it not less than if it was embraced inside its body.

Nam licet mater interdum varias ob causas ova sua tantisper deserat; eadem tamen usque amat, brevique rediens sinu suo complectitur, fovet, ac diligenter tuetur.

In fact although sometimes the mother for various reasons abandons her eggs for some time, however she always loves them and coming back after little time she embraces them with her womb, heats them and takes care of them with diligence.

Cum vero pullus aerem iam liberiorem quaerit, rupto cortice prodit in lucem, circa diem vicesimum primum aut vicesimum secundum.

But when by now the chick desires a more free air, after having broken the shell it goes out to the light about the 21st or the 22nd day.

De hac pulli exclusione sive nativitate, non est praetereundus Fabricii aliorumque fere omnium vulgaris error. Audiamus Fabricium[1] ipsum: Citius, inquit, indiget externo aere, quam cibo, cum alimenti adhuc aliquid intus supersit: in quo casu iam pullus, qui durum corticem, prae rostri mollitie, et corticis a rostro distantia, eoque intra alam adstricto, rumpere non valet, iam signum matri dat rumpendi necessitatis; id quod per vocem efficit emissam. Etenim pullus tunc ita robustus est, et cavitas tam ampla facta, et aer ita copiosus contentus, ut iam adaucta impensius respiratione, exsufflationem quoque et vocem emittat, naturalem quidem pullo, forteque quidpiam petentis significatricem; quae etiam exterius audiri facile a quolibet potest; praeterquam quod Plinius, et Aristoteles[2] id ipsum affirmant: Qua pulli voce protinus audita, quasi necessitatem rumpendi corticem cognoscens, ut nimirum pullus externo fruatur aere pro sui conservatione, aut, si mavis, dicas, pulli dilectique filii conspiciendi desiderio foetans affecta, iam rostro corticem rumpit; qui non difficulter abrumpitur, cum ibi loci propter cavitatem iam diu humoribus destitutam, et a contento aere, et calore exsiccatam fragilior friabiliorque evaserit. Vox igitur pulli primum et maximum signum est eiusdem exitum quaerentis, externoque [280] aere indigentis: quam ita exacte gallina percipit, ut si forte fortuna foetans pulli vocem internam infernamque esse dignoscat, tum sursum pedibus ovum revolvat; ut ea duntaxat parte qua vox venit, sine ulla pulli noxa corticem abrumpat. Addit et alterum signum Hippocrates[3] pulli ex ovo exire petentis; videlicet quod pullus, ubi alimento destituitur, fortiter movetur, uberius alimentum quaerens; et pelliculae circum disrumpuntur; et ubi mater sentit pullum vehementer motum, putamen exscalpens ipsum excludit.

About this exclusion, or birth of the chick, we don't have to omit the usual mistake of Fabrizi and of almost all others. Let us hear Fabrizi himself who says: «Rather in a hurry it needs external air instead of food, since internally still some food remains. In such case by now the chick, which is not able to break the hard shell because of the softness of the beak and the distance of the shell from the beak shut under the wing, by now it gives the signal to the mother of the necessity to break it, which it does by sending forth the voice. In fact now the chick is so strong and the cavity became so wide, and the contained air is so plentiful that, being the respiration by now increased rather abundantly, it is able to expire and to send forth the voice. And really it sends forth that voice which is natural for the chick and perhaps expressive of asking something, and which is also easy to be heard outside by whoever. Apart the fact that Pliny and Aristotle are affirming the same thing. As soon as this voice of the chick has been heard, almost aware of the necessity to break the shell, obviously so that the chick uses the external air to survive, or, if you prefer, you could say that the parent is seized by the desire to see the chick and the beloved child, then she breaks the shell with the beak. Which doesn't get broken with difficulty, since in that point, because of the cavity already since a long time deprived of liquids and dried by the air in it contained and by the heat, the shell became more fragile and friable. Therefore the voice of the chick is the first and greater sign of it asking to go out and needing external air, and the hen perceives the voice so well that, if perhaps by chance the parturient realizes that the voice of the chick is inside and below, then with the legs turns the egg upward in such a way that can break the shell, without any damage for the chick, only in that part from which the voice is coming. Hippocrates adds another sign of the chick asking to go out of the egg, that is, the chick, when devoid of food, moves with strength asking more abundant food and the pellicles around it get broken, and when the mother feels the chick moving with vehemence, then she does it to go out striking the shell.»

Haec a Fabricio festive quidem et concinne dicta sunt; solidis tamen argumentis haud innituntur. Experientia enim compertum habeo, pullum ipsum, non autem matrem, corticem frangere: idque rationi etiam quam maxime est consentaneum. Quomodo enim alias ova in fimetis, furnisque calidis, ut in Aegypto, alibique fit, rumpantur? ubi mater nulla adest, quae vocem supplicantis pulli, opemque implorantis audire queat. Testudinum marinarum et terrestrium, piscium quoque, bombycum, serpentum, et struthionum ova, quomodo frangantur? cum foetibus illis vel vox desit, qua exitum petant, vel sub terra sepulti exaudiri nequeant. Sponte igitur nascuntur pulli, atque ex ovis suis proprio molimine prosiliunt. Idque ita fieri, certissimis argumentis liquet. Quippe in prima ovi perforatione, hiatus iste multo minor est, quam ut matris rostro conveniat: sed pulli rostro directe respondet; circa quod, in modum coronae, corticem aequali semper a cacumine distantia ruptum videas, partesque confractas, praesertim primis ictibus, foras semper prominere. Quemadmodum autem ruptis vitreis fenestris, facile quis iudicaverit, intusne ictus an foris advenerit, si modo frustorum adhaerentium apices, quo tendant, diligenter intuitus fuerit; ita pariter rupto ovo, ex fragmentorum per totum coronae ductum eminentia, ab interna causa id proficisci [281] manifestum est. Quin egomet, aliique mecum complures, simul ac pullum audivimus corticem unguibus scalpere, vidimus quoque illico eundem rostro pertundere, rupturamque in circulum, coronae instar, deducere. Quinetiam vidi foetum capite suo corticis cacumen attollere et amovere.

Really these things are said by Fabrizi in a pleasant and elegant way, but they don't rely on solid proofs. In fact by experience I learned that the chick itself is breaking the shell, not the mother, and this is extremely consistent with a reason. In fact how otherwise would the eggs get broken in the dunghills and in the warm ovens as it happens in Egypt and elsewhere? Where no mother is which can hear the voice of the chick beseeching and begging for help. How would be broken the eggs of turtles and tortoises, also of fishes, silkworms, snakes and ostriches? Since those fetuses are devoid of voice by which to ask to go out, or, being buried under earth they cannot be heard. Therefore the chicks spontaneously hatch and jump out of their eggs thanks to their hard work. Then according to extremely sure data it comes out evident that the things happen in this way. In fact at the beginning of the perforation of the egg this hole is very smaller than the beak of the mother, but it exactly corresponds to the beak of the chick. In this regard, you can see that the shell is always broken at the same distance from the apex as being a crown, and that the broken parts, above all by the first strokes, always stick out outside. Likewise in case of breaking of glass windows whoever will be able to easily judge if the hit came from within or from outside if just we will examine with attention where are going the apexes of the fragments remained attached. So likewise for a broken egg it is evident, according to the prominence of the fragments in the whole layout of the crown, that this comes from an internal cause. In truth I myself, and a lot of other people together with me, when we heard the chick grazing the shell with the toenails, we also at once saw the chick perforating it with the beak and producing a circular break as being a crown. I also have seen the fetus lifting the apex of the shell with its head and to remove it.

Pluribus quidem haec deduximus, quod haud spernendae utilitatis sit speculatio: ut inferius constabit. Fabricii vero argumentis responsu facile est. Fateor enim, pullum intra ovum vocem edere, et fortassis aliquid petentis significatricem: non inde tamen sequitur corticem a matre frangi. Neque pulli rostrum adeo molle, aut a cortice remotum est, ut hunc perforare non possit; praesertim cortice iam, ob causas ab eo allatas, valde friabili reddito. Nec semper caput intra alam reconditum tenet, ut ideo corticem rostro frangere nequeat, sed solummodo cum dormit, aut vita defungitur. Interdum enim, ipsomet quoque fatente, vigilat, calcitrat, scalpit, radit, distringit corticem, luctatur, membranas involventes rumpit, vocem edit (eandemque, opem implorantis esse, non invitus concessero); haecque omnia a quolibet facile audiri possunt. Quare gallina sedulo auscultans, quamprimum vocem ab ima parte attolli percipit, ovum quidem non rumpit; sed pedibus suis sursum revolvit, commodioremque situm pullo intus incluso praebet. Non constat autem, pullum voce sua rumpendi corticis necessitatem matri indicare, aut exitum ab ea petere. Nam saepe, per biduum ante exclusionem, pullum in ovo pipientem audias. Nec mater, dum ova revolvit, rumpendi ea locum quaerit; sed, ut infans, cum in cunis se male habet, inquietatur, plorat, eiulat; materque illius amans, huc illuc sedulo ab uno latere in aliud removet, agitatque, donec ille placatus fuerit: ita similiter gallina, ubi pullum tumultuantem, pipientemque in ovo senserit, vel iam ex ovo exclusum in nido sese inordinate commoventem; protinus se attollit, cavetque, ne corporis sui pondere, [282] vel calore nimio eum laedat, rostroque pedibusque ultro citroque volvit, donec foetui quietem atque indolentiam comparaverit.

Really we deduced these things on the basis of several observations, since the observation is not something whose utility must be despised, as later it will appear. It is easy to reply to the affirmations of Fabrizi. In fact I affirm that the chick inside the egg utters a voice and that perhaps this has the meaning of asking something; however because  of this it doesn't follow that the shell is broken by the mother. And neither the beak of the chick is so soft or far from the shell to not be able to perforate it, above all since the shell now became very friable, for the reasons by him alleged. Neither always it holds the head hidden under the wing in such a way to then not be able to break the shell with the beak, but only when it sleeps or dies. In fact sometimes, as also he himself declares, it is awake, kicks, grazes, scrapes, stretches the shell, fights, breaks the winding membranes, sends forth a voice (and very gladly I will admit that it is of someone asking help), and all these things can easily be heard by whoever. Therefore the hen by listening with attention immediately perceives that the voice raises from the lowest part, then she doesn't break the egg, but with her feet turns it upward and offers a more comfortable position to the chick shut up inside. In fact it doesn't result that the chick with its voice points out to the mother the necessity to break the shell or that it ask her to go out. In fact you can often hear for two days before hatching that the chick peeps inside the egg. Neither the mother, while is turning the eggs, looks for the point where to break them, but, as when an infant feeling ill at ease in the cot is restless, cries, moans aloud and his mother who loves him moves him with care from a side to the other, here and there, and she rocks him until when he will be reassured, so in the same manner the hen, when feels the chick shouting and peeping inside the egg, or that already gone out of the egg it stirs in a messy way in the nest, she immediately rises and takes care not to damage it with the weight of her body or with too much heat, and with the beak and the feet she turns it here and there until when she has not gotten tranquillity and calm to the fetus.