Post exclusionem reperi in putamine tunicas duas albas nativas una cum duabus aliis in incubatu genitis, secundina nempe, et quae foetum ipsum involverat, in qua excrementum adhuc inerat subalbidum. Evidenter adhuc apparebant in pullo tria illa vasa umbilicalia, duae scilicet arteriae, et vena una, et orificium umbilici valde erat contractum. Vena vero iecori per alium ramum, qui recta ad illud tendebat, inseri videbatur. Mirum autem erat, quod extra id nihil lutei appareret, cum tamen in cavitate abdominis, ubi intestina sunt, prope anum pullus per umbilicum totum fere id absorbuerat, simul cum quinta tunica, quae id involverat. Tanta autem ibi lutei inerat copia, ut vix duplo plus sit in ovo nondum incubato. Aristoteles etiam scripsit[1], decima ab ortu die si alvus abscindatur aliquid adhuc lutei in ea conspici. Sed consideratione in primis dignum est, quomodo eiusmodi membrana, quam una cum vitello a pullo absumi diximus, post eijciatur. Videtur autem dicendum, quod per eandem viam, {umbelicum} <umbilicum> videlicet, regredi debeat, vel per anum, quod potius credo. Tunicae huic duo vasa implantantur, quorum unum arteriam esse, et a corde proficisci pulsus indicat: alterum vena est, deferturque ad intestina, lutei videlicet vehiculum{:}<.> Hepar erat coloris admodum lutei, forte quod ex luteo per venas attracto nutriatur.

After the chick was hatched I found in the shell its two white tunics together with the two other created during incubation, and precisely the placental one – allantoid - and that which had enveloped the foetus itself – amnios - in which a whitish secretion was still present. In the chick they were still quite clearly visible those three umbilical vessels, that is, two arteries and one vein, and the opening of the umbilicus was greatly shrunk. It was possible to see the vein to plug into the liver by another branch which was straight going towards it. It was remarkable that, besides this, nothing of the yolk was visible, since through the umbilicus the chick had absorbed it almost completely in the abdominal cavity where the intestinal loops are near the anus, along with the fifth tunic which had enveloped the yolk. For there was so great a quantity of yolk that in an egg not yet incubated there is barely more than twice of that amount. Aristotle also wrote that if on the tenth day from birth the abdomen is cut, one can still see some of the yolk in it. But it is worth noting first of all how a membrane of this sort, which I said is absorbed by the chick together with the yolk, is later thrust out. It seems we should say that it ought to move out through the same passage, that is, the umbilicus, or through the anus, which I should prefer to believe. Two vessels are implanted in this tunic, one of these being an artery, and its pulsation indicates that it proceeds from the heart: the other is a vein and goes to the intestinal loops, evidently the vehicle of the yolk. The liver was of a rather yellow color, perhaps because it was nourished by the yolk attracted through the veins.

Praetereo modo tritam illam, ideoque otiosam potius, quam curiosam quaestionem, num Gallina prior ovo sit, an contra. Constat enim Gallinam fuisse prius ex sacris bibliis, quae docent animalia ab initio mundi fuisse creata: non igitur ex ovo Gallina, sed ex nihilo. Quod si vero quis obstinatius dicat, omnia quae sunt aliquando coepisse, ideoque ovum a natura iure prius factum videri, quoniam quod incipit, imperfectum adhuc, et informe sit, et ad perfectionem sui per procedentis artis, et temporis additamenta formetur. {. Ille} <, ille> facile acquieturus est, dum ovum, cuius est, nec initium, nec finem esse sciat. Nam initium semen est, finis avis ipsa formata, ovum vero seminis digestio. Cum igitur semen animalis sit, et ovum seminis: ovum sane ante animal esse non potuit. Quod si rursus ova avium seminaria esse dicat, ipsum quid semen sit ignorare dicam. Semen autem ex Philosophorum sententia, generatio est ad eius, ex quo est, similitudinem pergens. Quomodo itaque queat ad similitudinem rei pergi, quae necdum est? Sic etiam neque semen ex eo, quod nondum subsistit, emanat. Verum de hac quaestione Plutarchum[2], Macrobium[3] lector consulere poterit, qui exacte eam tractant. Nobis enim diutius ei immorari et locus, et tempus prohibent.

I barely glance at that trite and then otiose rather than curious question, whether the hen exists before the egg or vice versa. It turns out from the Scriptures that the hen existed first, and they teach that animals were created from the beginning of the world: hence the hen does not come from the egg but from nothing. But if someone rather stubbornly should affirm that all things which exist began in a given moment, and that therefore the egg rightly seems to have been created first by Nature, since what has a beginning is still imperfect and formless and it makes its way to its perfection by a progressive addition of work and time, he would easily calm himself, since he must know that an egg, whosever it is, is neither the beginning nor the end. For the beginning is the semen, the end is the formed bird itself, but the egg is the concoction of the semen. Since therefore the semen is of the animal, and the egg is of the semen, obviously the egg cannot will have been before the animal. But if, on the other hand, he should affirm that birds’ eggs are seedbeds, I should say he does not know what a semen is. For, according to the philosophers’ point of view, a semen is a procreation proceeding towards the likeness of that from which it comes. How then could it proceed towards the likeness of something which does not yet exist? Thus also the semen does not proceed from what does not yet exist. Concerning this question the reader might consult Plutarch and Macrobius, who treat it exactly. For both time and space prevent me from lingering on it any longer.

Pariunt Gallinae, Perdicesque ova complura, ut, Aristoteles tradidit, et Plinius ex eo repetiit, et quotidiana experientia docet: aliae tamen aliis plura pro aetatis ratione: iuvencae enim, teste Plinio[4] plura, quam veteres, sed minora, et in eodem foetu prima ac novissima pariunt. Quare Varro[5] anniculas ad partum, aut bimas appositissimas dicebat. Confecta vero bruma parere fere incipiunt, atque earum, quae sunt foecundissimae locis tepidioribus circa calendas Ianuarias, frigidis eodem mense post idus[6]. Coeunt autem, et pariunt omnibus anni temporibus, exceptis brumalibus diebus, teste Aristotele[7], qui tamen alibi binos brumales menses excipit, quam postremam sententiam Plinius sequutus est, et experientia comprobat[8]. Pariunt tamen nonnullae et his diebus sed raro. Sunt quae tam multa pariant, ut id bis etiam die faciant. Sed tales, teste Aristotele[9], cito pereunt. Hyperinae[10] enim, id est, exhaustae, effoetaeque et aves, et plantae fiunt. Optima foetura est, quae ante vernum aequinoctium {a}editur. Post solstitium nata non implent magnitudinem iustam, tantoque minus quanto serius provenere. Unde dicebat M. Varro[11]: Aiunt optimum esse partum {aequinoctio verno, aut autumnali} <ab aequinoctio verno ad autumnale>. Itaque quae ante, aut postea nata sunt, et etiam prima eo tempore non supponenda. Sed de differentiis partus supra diximus.

Hens and partridges lay many eggs, as Aristotle reports and Pliny quoted from him, and as daily experience teaches us: however some birds lay more than others because of their age: for young birds lay more than old ones, according to Pliny, but eggs are smaller and in a same laying career they are such the first and the last ones. Therefore Varro said that year-old or two-year-old hens were best for laying. They chiefly begin to lay when winter is over, and in warmer places the most fertile among them do lay around the kalends of January - January 1st, in cold places in the same month after the ides - January 13th. They have coitus and lay at all times of the year, however, except during the winter days, according to Aristotle, who nevertheless elsewhere excepts a couple of winter months, and Pliny followed this affirmation and the experience confirms it. Some hens lay even during these days, but seldom. There are some hens who lay so many eggs that they do so also twice a day. But such hens, according to Aristotle, die in a short time. For both plants and animals become hyperinae, that is, exhausted and worn out by delivery. It is the best breed-product that one which takes place before the vernal equinox. Those laid after the summer solstice do not reach their proper size, and the less the more later they have been laid. Hence Marcus Varro said: They say the best delivery is that from the vernal until the autumnal equinox. Thus the eggs laid before or after, and even the first ones laid at that time should not be set under the hens for incubation. But I have spoken above of the different features of egg-laying.

Parituram sese Gallina clamore prodit, eodemque peperisse se testatur, quod si impediatur, mox tamen sibi relicta cantum absolvit: eiusmodi cantum Columella[12] singultum appellasse videri potest, dum ait: Parituras se Gallinae testantur crebris singultibus interiecta voce acuta. Sunt qui dolere eas, cum pariunt, arbitrantur. Ambrosius Nolanus quaerens cur solae Gallinae parto ovo gracillent, sive cantent: An quia, inquit, tum maxime dolent, non eo quod exiens ovum laesit, sed quoniam locus vacuus factus aerem suscepit frigidum, quo pacto et lotium facientibus, dum vesica inanita est, aërem capiens dolorem movet quendam. Verum nunquid ob ingressum in vulvam aërem doleant, si modo verum est, quod doleant, aliis diiudicandum reli<n>quo. Profecto parere eas sine dolore ex Aristotele colligitur, dum, ut antea quoque diximus, testam membranam mollem [220] fuisse scribat ante partum.

A hen by cackling lets know that she is about to lay, and still by cackling announces that she laid, but if prevented from doing this, as soon as left to herself she breaks out her song: it seems that Columella called this song a hiccup when he says: Hens announce that they are about to lay by frequent hiccups with interposition of a shrill call. There are people who think hens are in pain when they lay eggs. Ambrogio Leone - Ambrosius Leo Nolanus - when wondering why only hens caw, or sing after laid the egg, he says: Perhaps because they are then especially pained, not because in passing out the egg has wounded them, but because the place made empty has received cold air, as it happens also to those who are urinating, where the vesica, when empty out, in receiving air is bringing them a certain pain. To say the truth, I leave for others to judge whether they are in pain because of entrance of air into genital apparatus, if really it is true that they grieve. Without any doubt it can be gathered from Aristotle that they lay without pain since, as I said earlier, he writes that before delivery the shell is a soft wrapper.