[8] De pennatorum uteri actione, videlicet de Ovorum
generatione.  CAP. 2.

Part I
Chapter II
The activity of the uterus of the birds
that is
the generation of the eggs

Non est, quod dubitemus (auditores) an pennatorum uteri actionem habeant, necne; Neque est, quod in ea indaganda laboremus; quoniam ex pluribus, unus modus, qui nos in organi interni ignotam actionem ducit, maxime omnium huic proposito congruit, qui ex opere facto actionem detegit. Nam sicuti dicimus, ventriculi actionem esse chylificationem, et testium actionem seminis generationem, quia in ventriculo chylus, in testibus semen comperiatur; sic ovorum generationem esse pennatorum uteri actionem omnino asseveramus, quod ovum inibi inveniatur. {Qninimmo} <Quinimmo> chylus, et semen alibi quoque, quam in ventriculo, et testibus, ille quidem etiam in intestinis, hoc vero in vasis spermaticis reperitur: at ovum nullibi unquam, quam in matricibus, quas, ideo pennatorum ovarium appellavimus, consistit. Sicut sensui conspicuum est.

Disciples, there is no reason to doubt whether or not the uteri of the birds are endowed with activity, neither to get tired in investigating it, since among many manners only one exists leading us to an unknown function of an internal organ, that mainly coincides with this intention, which method discloses the function according to the produced effect. In fact, as we say that the activity of the stomach is the production of the chyle* - today chyme* - and that the activity of the testicles is the generation of the semen, since the chyle is found in the stomach and the semen in the testicles, so we are quite guarantors of the fact that the activity of the uterus of birds consists in the generation of the eggs, since really there the egg is found. In truth the chyle and the semen are found also in points different from stomach and testicles, the first one also in the intestines, the latter in the spermatic vessels, but the egg is never present in different points than the uteri which therefore we called ovary of birds. As it is evident at the observation.

Itaque instrumentum, et locus generationis ovorum nobis omnino cognita sunt, et perspecta. Praeterea vero, cum duo sint uteri in pennato, superior, et inferior, iique inter se admodum dissimiles, ideoque dissimilem actionem habentes, similiter clarum est, quaenam sit utrique peculiaris actio concredita. Etenim superior ad vitelli, inferior ad albuminis, et reliquarum partium, seu totius ovi generationem substituitur, ut sensu patet: In superno enim nil aliud, quam vitellorum multitudo, in inferno vero totum perfectum ovum continetur. Aristotelem autem nullam habuisse notitiam secundi memorati uteri, patet ex verbis 6. de hist. an. cap. 2.[1] positis, ubi habet. Concipit foemina, quae coierit, ovum superius ad septum transversum; quod ovum primo minutum, et candidum cernitur, mox rubrum, cruentumque: deinde increscens luteum, et flavum efficitur totum. Iam amplius auctum discernitur, ita ut intus pars lutea sit, foris candida ambiat. {ubi} <Ubi> perfectum est, absolvitur, atque exit putamine, dum paritur, molli, sed protinus durescente, quibuscunque emergit portionibus.

Insofar the device and the point of generation of the eggs are completely known to us and analysed. Besides, since in a bird the uteri are two, superior and inferior, and besides they are very different each other, and therefore they have a different activity, likewise it is clear what is the specific activity assigned to each of them. In fact the superior uterus is devoted to the generation of the yolk, the inferior to the generation of the albumen and of the remaining parts, that is, of the whole egg, as it is clear when observing. In fact in the superior nothing is contained but a crowd of yolks, in the inferior the whole completed egg. That Aristotle didn't have some knowledge of the quoted second uterus it is clear from the words of Historia animalium VI,2 where he writes what follows. The female that joined conceives an egg aloft near the transverse septum and this egg, which at first appears small and white, subsequently becomes red and blood red. Then, increasing, it becomes entirely yellow and golden. When it became larger we can see that the yellow part is located internally, externally the white part acts as belt. When completed it is released and when laid it comes out with a soft shell, but immediately becoming hard, and it goes out with all its parts.

Idem elicitur ex primo de gen. an. cap. 3.[2] ubi uterum avibus omnibus iuxta septum transversum positum esse affirmat. Idem multis in locis clarius. Ex quibus Aristotelis verbis liquet, ipsum totum ovum perfici superius in vitellario voluisse, sed postea vitellum ab albumine discerni. At sensus testatur, duplicem esse uterum, et alium esse vitelli generationis locum, alium albuminis, uti infra exactius dicetur. Igitur levi negotio una uterorum actio, quae conceptus dicitur, et ovi generatio nuncupatur, inventa iam a nobis est. Sed non est haec sola uterorum functio, ut patet; sed ea quoque adnotatur, et enumeratur, nimirum ovi augmentum, quod ovo statim genito succedit, quousque perfectum efficiatur, et iustam magnitudinem adipiscatur.

The same thing is inferred from De generatione animalium I,3 where he affirms that in all birds the uterus is located near the transverse septum. The same thing is more clear in many passages. From these words of Aristotle it is evident that he established that the whole egg is completed aloft in the structure of the yolks, but that afterwards the yolk remains distinct from the albumen. But the visual experience is witness of the fact that the uterus is double and that one is the place of the generation of the yolk, the other one is that of the albumen, as afterwards it will be said with more accuracy. Insofar with our little effort an activity of the uteri has already been discovered, which is called conception and generation of the egg. However the function of the uteri is not only this, as it is clear, but is also observed and numbered above all that of the growth of the egg immediately following the produced egg until it becomes perfect and acquires the correct size.

Etenim Gallina non prius naturaliter ovum parit, quam perfectum factum, et congruam magnitudinem adeptum. Igitur uterorum actio, tum ovi generatio, tum augmentum est; augmentum autem nutritionem supponit, et includit, ut patet. Sed cum generatio omnis a duobus perficiatur, videlicet opifice, et materia, quo modo in lactis concretione, lac ipsum ut dicebat Arist.[3] materia est, herbae vero succus[4], seu coagulum, quod [9] inspissandi vim habet, rationem agentis obtinet; iam de utroque agendum est. Agens in ovorum procreatione nil aliud est, quam instrumenta, seu organa proposita, nimirum duplex uterus{.}<,> materia vero nulla alia, quam sanguis. Etenim sanguis is est, ex quo non modo ovum, sed quodcunque fere in animali corpore, boni gratia, fit, resultat.

In fact the hen doesn't lay the egg in a natural way before it has been completed and acquired a suitable dimension. Insofar the activity of the uteri consists both in the generation of the egg and in its growth, and the growth presupposes and implicates a nutrition, as it is evident. But since each generation is ended by two agents, that is by the creator and by the matter, alike in the coagulation of the milk, as Aristotle said, the milk itself is the matter but the juice of the grass, or rennet*, endowed with the capacity of thickening, possesses the label of performer, then we need to speak of both. In the generation of the eggs the performer only consists in the described tools, or organs, that is, the two uteri, while the matter is constituted only by the blood. In fact the blood is that from which not only the egg arises, but practically anything that for a good purpose happens in the body of an animal.

Non igitur mireris, si ad huiusmodi uteros membranosos, frigidos, tenues, et sua natura exangues, quae partes communiter pene sine venis conspiciuntur, sanguinem copiosissimum per suum mesenterium, per similitudinem quandam appellatum, per numerosa, amplissimaque vasa traductum conspicias. Porro hic sanguis a proprietate substantiae duorum uterorum alteratus, et immutatus, tandem in ovum evadit, et migrat, diverso tamen modo. Nam in vitellorum ovario, vitelli tantum procreantur, qui colore inter flavum, et pallidum constant: quique temperie a sanguine parumper distant, et parum abest, quin totus vitellus sanguis sit: Unde Avicenna non sine ratione tantum nutrire, quantum ponderat, dixit[5]. Ideoque verisimile est, a purissimo, temperatoque sanguine vitellum generationem suam esse adeptum existimare, qui potius concretus sanguis sit, quam plene concoctus. Etenim mollissimus vitellus est, et quasi fluidus, ut sanguis; colore flavus, fereque rubeus, ut sanguis; temperatissimus, ut sanguis.

Insofar we could not be surprised if we see that the blood in great abundance, through their mesentery, so called for a certain similarity, and through numerous and very wide blood vessels, is brought to such membranous uteri, cold, thin and bloodless for their nature, structures that usually are almost without veins. In addition this blood, altered and modified by the structural characteristic of both uteri, finally comes and moves to the egg, nevertheless in a different way. In fact in the ovary of the yolks only the yolks are produced, endowed with a colour between yellow and pale, and that for composition differ only slightly from the blood, and nearly the whole yolk is blood. Then Avicenna* rightly said that it nourishes as much as it weighs. It is therefore likely to think that the yolk took origin from a very pure blood and mixed in right amount, since it is a rather dense than completely digested blood. In fact the yolk is very soft and almost fluid as the blood, is yellow in colour and almost reddish as the blood, it is very mixed in right amount as the blood is.

Dixi autem, vitellum magis concretum esse sanguinem, quam plene concoctum propter eam rationem, quod rursus in Sanguinem migrare vitellum oportet{;} in pulli nutritione, et augmento; quod fieri utique non posset, si vitellus per calorem insignem, completam diversae formae absolutionem fuisset adeptus. Albumen autem et ipsum ex sanguine constat similiter a propositis venis attracto, sed alterato, immutatoque in albuminis formam a substantiae proprietate secundi uteri, cuius generatio ex frigidiori, pituitosaque sanguinis portione fit, quam ideo non est difficile per ulteriorem concoctionem rursus in sanguinem migrare, uti paulo post in usibus audietis.

In fact I said that the yolk is more a thick than a completely digested blood, being necessary that the yolk newly turns into blood during the nutrition and the growth of the chick. However this could not happen if the yolk, through a high heat, had reached a complete improvement of a different aspect. Also the albumen itself turns out to be formed in similar manner from the blood drawn from the aforesaid veins, but modified and turned into albumen by the structural characteristics of the second uterus, whose generation comes from the more icy and cold part of the blood, which therefore is not difficult to be turned again into blood through a further digestion, as soon you will hear about the uses.

Sed in hoc secundo pennati utero non modo ovi albumen gignitur, sed reliquae etiam ovi partes procreantur. Sunt autem primum duo corpora grandini similia; unde {χάλαζα} <χάλαζαι>, ab Arist. appellantur[6], quae alba sunt, nodosa, concreta, luciditatis {cuius quam} <cuiusquam> non expertia, ut grando, quaeque in albumine quidem degunt, sed ovi vitello magis quam albumini adhaerescunt, et eius membranae appenduntur. Sunt vero χάλαζαι duae, altera et minor in acuta ovi parte[7] consistens; altera in latiore, et obtusa, quae maior est, et longior ex duobus, tribusque nodis quasi grandinis globulis, granisque conflata, quae in secundo hoc utero statim, ac vitellus illuc pervenit, ex crassiore sanguinis portione ab uteri substantia gignitur.

But in this second uterus of the bird not only the albumen of the egg is produced, but also the remaining parts of the egg are created. First of all there are two structures similar to hail, thence by Aristotle they are called chálazai - chalazae, which are white, nodular, consistent, nevertheless not deprived of a certain brightness as the hail, and they lie in the albumen, but they stick more to the yolk of the egg than to the albumen and are adherent to its membrane. The chálazai - chalazae - are two, the smaller one is placed in the acute pole - no! the obtuse - of the egg, the other one, that is the greater and the longer, is placed in the wider and obtuse side - no! acute, composed by two and three nodes as if they were grains and little grains of hail, and is produced in this second uterus by the uterine structure starting from the denser part of the blood as soon as the yolk arrives here.

Deinde in hoc inferno utero duae membranae procreantur totum ovum obvolventes, quarum una exterior est durior, densior, et fortior cortici proxima; altera interior, mollior humores contingens. Postremum, quod in ovo generatur, est putamen, seu cortex, operculum scilicet exterius positum, durum, frangibile, candidum, densum, magis adhuc crassa, pituitosa sanguinis parte, genitum. Verisimile autem est, varia haec corpora, videlicet chalazas, albumen, membranas, et corticem non modo ex vario sanguine procreari, qui per maiorem, minoremque crassitiem differat; sed etiam variam [10] uteri partem habere constitutam, ac destinatam: propter quam causam hic secundus uterus commode in tres partes potest distingui, licet continuus per totam eius longitudinem sit, principium, medium, et finem: omitto nunc infundibulum, quod membranosum cum sit, tenuissimum, et venis vacuum, ideo uteri nomine dignari non debet, propterea infundibulum appellatum est, quamvis utero continuatum sit.{)}

Moreover in this inferior uterus two membranes are produced enveloping the whole egg, one of which is exterior, harder, thicker and more resistant, placed near the shell, the other one is placed inside, is softer and in contact with the liquids. Finally what is produced in the egg is the shell or peel, that is a coverage externally placed, hard, breakable, white, compact, produced by the even more dense and cold part of the blood. But it is likely that these different structures, that is, the chalazae, the albumen, the membranes and the shell are produced not only from a different blood, differing for the greater and lesser density, but that they have also a different part of the uterus structured and destined to them. That's why this second uterus for convenience can be divided into three parts, although it is continuous in all its length, that is, the initial, the middle and the terminal part. Now I omit the infundibulum which, being membranous, very thin and without veins, therefore doesn't deserves to be called uterus, thence it has been called infundibulum nevertheless it is in continuity with the uterus.

Principium igitur secundi uteri sit, ubi uterus propria donatur substantia crassiore, albidiore, et venis referta, quae infundibulo continuatur, ubi chalazae efficiuntur, et primo quidem in obtusa ovi vitelli parte nectuntur, inde in acuta[8]. Huic succedit secunda uteri pars media, amplior, longior, et spiris convoluta, plicisque intus referta, ubi albumen gignitur, et circa vitellum obducitur. Hanc ultimo tertia uteri pars sequitur, sed in prima huius partis regione, ovi duae membranae generantur: in secunda, et postrema cortex, qui, ut par est, primo mollis, inde durus efficitur.

Then the beginning of the second uterus has to correspond to where the uterus is endowed with its denser, whiter and rich of veins substance which continues with the infundibulum, there where the chalazae are prepared sticking to the yolk, first at the obtuse part of the egg, then at the acute one. This part is followed by the second middle part of the uterus that is greater, longer and twining in coils, and internally rich of plicae where the albumen is produced and applied around the yolk. Finally to this is following the third part of the uterus, but in the first section of this part the two membranes of the egg are produced. In the second and last section the shell is produced, which, as it is natural, at first is soft and then becomes hard.

Fieri autem in hoc secundo utero omnia iam memorata corpora confirmari potest, per exiguum ovum, quadruplo caeteris minus, quod vulgus putat esse ultimum gallinarum, cum iam centum ova gallina peperit, et emiserit, (unde centenino vulgo dicitur, et a rusticis disperso) quod sine vitello est, habet tamen caetera, ut chalazas, albumen, membranas, et corticem; Verisimile enim est, tunc generari, cum vitelli omnes iam in ova migrarunt, neque amplius in vitellario aliquis superest vitellus, qui in ovum evadere possit: ex altera tamen parte, albuminis adhuc modicum superest.

That in this second uterus all the just mentioned structures are created, can be confirmed through that small egg four times smaller than the other eggs, which the people think to be the last of the hens, when the hen has already created and laid one hundred eggs (thence it is commonly called centenino – hundredth, and disperso - dispersed - by the farmers), since it is without yolk, while it has the remaining structures as the chalazae, the albumen, the membranes and the shell. In fact it is likely that it is produced when all the yolks are by now migrated in the eggs, and in the upper uterus no yolk remains that can become an egg, while in the other uterine structure a moderate quantity of albumen still remains.

Ex hoc, enim modico credibile est, ovulum propositum creari, et quod in medio rotundum corpus {praesefert} <prae se fert> vitellum, sed tamen est ex albuminis substantia conflatum; quod non inepte effaetum ovulum appellari potest. Quo loco ignorare non oportet ovum vulgo centeninum appellatum duplex reperiri, alterum sine vitello, et hoc vere centeninum dicitur, over disperso, quod est ultimum a gallina emissum, cum quo gallina omnino cessat eo anni tempore ab ovis pariendis: alterum est similiter pusillum ovum quod vitellum habet, et non est ultimum a gallina editum, sed intermedium est, et post illud gallina adhuc sequitur ova parere iustae magnitudinis, sicuti antea: sed deficit in magnitudine propter diminutam facultatem vegetalem, sicuti accidit persico et aliis plantis, quae modo quidem {plurima} <plurimae> iustae magnitudinis: {nonnulla} <nonnullae> autem perpusilla efficiuntur, et remanent.

In fact it is credible that the aforesaid small egg is produced from this modest quantity of albumen and that that round body in the centre shows a yolk, but nevertheless it is composed by the substance of the albumen, thence rightly it can be called little sterile egg. At this point it is necessary to know that two eggs commonly called hundredth are found, one without yolk, and this is rightly said hundredth or lost, since it is the last one laid by the hen, with which the hen stops completely to lay eggs in that period of the year. The other one is likewise a small egg which has the yolk and is not the last one laid by the hen, but it is intermediary, and after this the hen still continues in laying eggs of correct size as before; but it is scanty in dimensions because of a reduced life-giving power, as it happens to the peach and other trees: nevertheless those of correct size are a lot, however some grow very small and such they remain.

Iam igitur liquet, quomodo vitellus, albumen, chalazae, membranae, et putamen ovi generentur: sed age, nunc quo ordine tum generentur, tum perficiantur ovi partes sigillatim repetamus. Vitelli primo in vitellorum ovario, seu racemo minimi, ut sinapis, miliique granum expullulant; inde maiores, grandioresque, et denique ad iustam magnitudinem perducti, a proprio pedunculo, membranaque ab ipso producta, separantur, caduntque in infundibulum; et ab eo in secundi uteri principium devoluti, atque in prima spira detenti, chalazas acquirunt. (Quod persuadet, quia chalazae vitello [valde] valide nectuntur).

Insofar it is by now clear how the yolk, the albumen, the chalazae, the membranes and the shell of the egg are produced. But courage, now let me see to repeat in what sequence the parts of the egg are both produced and ended one by one. First of all the yolks germinate in the ovary of the yolks, or cluster, and they are very small, as a grain of mustard* and mile*; then, after becoming larger and bigger, and finally, brought to the correct size, they separate from their stalk and from the membrane produced by the stalk itself, and they fall in the infundibulum. After they passed from the infundibulum to the initial part of the second uterus, and being kept in the first coil, they acquire the chalazae. (Which is believable, since the chalazae are firmly attached to the yolk).

Inde sensim descendentes dum per secundi uteri spiras volutantur, iam undique albumen, quod in internis plicis reservatur, illis apponitur, adhaerescit, et quodammodo incrustatur; Nam hoc modo fieri albuminis circa vitellum appositionem, et applicationem, adhaerentiamve, ovum coctum durum, iudicio est; in quo eiusmodi [11] laminas, seu orbes, seu crustas apparere omnibus patet.

Then, going down little by little, while they are rolling through the coils of the second uterus, the albumen, which is stored in the internal plicae, is applied all around them, it sticks and in some way covers. In fact, that the apposition and the application, or adhesion, of the albumen around the yolk happens in this way, the hard boiled egg is a proof, in which it is evident to all of us that such layers or circular formations or coverings are visible.

Albumen igitur circa vitellum obduci in mediis spiris, medioque utero crassiore {verissimile} <verisimile> est, dum scilicet sensim vitellus per spiras volutatus descendit: et quia per prius et posterius generatur, et apponitur, fit ut quod priore loco apponitur crassius, quod vero posterius, liquidius existat. Neque dubites, quomodo albuminis tanta copia in plicis iam suppetat, ut pro ovi perfectione sufficiat, quoniam simile quid hic accidit, ac in ventriculo{:}<.> {Si.n.hic} <Si enim hic> plus chyli facit, quam sit pro sui nutritione ex usu, et reliquum tanquam superfluum a se ablegat, cum tamen toti corpori utile sit: ita secundus hic uterus propter venas plures, et quam suae moli conveniat maiores, quas excipit, copiosius quoque, quam suae naturae competat alimentum conficit, ac praeparat, ut puta albumen; quo abunde saturatus, quod reliquum est, quando multum, et copiosum est, ut sensu patet, ibidem deponit, atque in plicis reservat, ut vitello copiosum semper suggeratur albumen, quod revera utero superfluum est, quamvis sit pro ovi generatione utilissimum.

Therefore it is likely that the albumen is stretched around the yolk in the middle coils and in the medium uterus which is more thick, that is, while the yolk, rotating, slowly goes down through the coils. And since the albumen is produced and applied as first and as last, it happens that that applied as first is denser, while that applied afterwards is more fluid. And you don't have to doubt that so much abundance of albumen is available in the plicae so to be enough for the improvement of the egg, since here it happens something similar to what happens in the stomach. In fact, if this produces more chyle than necessary to its nourishment, and moves the remainder away from itself as being superfluous, even if at least it is useful to the whole body, so this second uterus, being greater than suitable to its dimensions due to the numerous veins it houses, also makes a more abundant food than is relevant to its nature and prepares it as albumen. Richly full of it, what remains, when it is a lot and abundant, as it is evident at a look, it always lays it in the same point and preserves it in the plicae so that the albumen is furnished to the yolk always in an abundant amount, since in reality it is useless to the uterus, while it is very useful for the generation of the egg.

Ubi autem iam albuminis iusta quantitas ovo porrecta est, quod in ultima spira contingit, tunc natura membranas humores obvolventes, continentesque creat, primoque interiorem molliorem, tenuioremque; mox illi proximam crassiorem, et firmiorem desuper imponit; ultimo cortice obducit. Atque hoc modo ovum; et omnes eius partes generari in utroque utero rationi consentaneum est: haecque una est prima, et praecipua pennati uterorum actio. Sed quia ea lege ovum generatur, ut adaugeatur, et perficiatur, quae actiones uterorum praedictorum sunt quoque propriae, et propositam statim consequuntur, de his quoque agendum est.

Actually, when the correct quantity of albumen has been supplied to the egg, what happens in the last coil, then nature creates the membranes enveloping and containing the liquids, at first that inside softer and thinner, then, near this, it superimposes one thicker and more resistant, lastly it covers with the shell. And it is logical that the egg and all its parts are produced in this way in both uteri, and this is the first and principal activity of the uteri of a bird. But since the egg is produced on condition that it increases in volume and is completed, activities also pertinent to the aforesaid uteri, that immediately reach the purpose, we have also to attend to them.

Quomodo autem incrementum suscipiat ovum, dubium admodum est. Idcirco iure ab Arist. 3. de gen. an. c. 2.[9] quaeritur quomodo ovum in utero augeatur simul ac nutriatur cum neque ut animalia per umbilicum, cibum capiat, cum umbilicum non habeat: neque ut vermes adaugeatur: cumque exeat ovum integrum cum molli cortice, et membranis, neque in ipso appareat aliquis porus, {perquem} <per quem> nutriri, et augeri possit, neque aliquid, quod utero adhaereat; Respondet[10] vero adesse in ovis, dum mollibus membranis obvolvuntur, canalem umbilicalem in acuta ovi parte, ubi ovi principium est, per quem augetur. Id quod probat ex {eiectitiis} <eiecticiis>  inchoatis ovis.

But how the egg increases its volume is very doubtful. Therefore rightly Aristotle in De generatione animalium III,2 wonders how in the uterus the egg increases its volume and at the same time is fed, since it neither receives food through the navel as the animals, not having a navel, nor it grows as the worms. And since the egg goes out intact with the soaked shell and with the membranes, and no opening in it is visible through which it can be fed and increased, neither something sticking to the uterus, Aristotle indeed answers that in truth in the eggs, while they are wrapped by soft membranes, an umbilical channel is present at the acute side of the egg, where the primordium of the egg is placed and that through such channel it grows. He shows this by using the abortive sketchy eggs.

Nam ubi avis aut madefacta[11], aut inalgens eiecit, cruentum {ad huc} <adhuc> cernitur intus ovum habens sibi annexam appendiculam umbilicalem. Sed cum Arist. duo dicat; alterum quod ovi principium in parte acuta sit altissimum quod inibi sit appendicula umbilicalis, qua ovum augetur: nos tamen neutrum esse verum observamus. Neque enim ovi principium est acuta eius pars, sed potius obtusa, in acuta autem qua parte pullus neque generatur, uti suo loco demonstrabitur: neque praeterea in membranis, [nulloque] multoque minus in cortice aliquid appenditur quod alimentum deferat intus in ovum; immo quod maius adhuc est, neque etiam potest quicquam adesse, quod ab utero ad ovum perveniat, aut fistula, aut canalis, aut vena, aut porus, quod ovum utero iungat, quo nutriatur, et adaugeatur.

Really when a wet or a chilly bird expelled it, we see that internally the still bloody egg possesses annexed a small umbilical appendix. But since Aristotle says two things, one of them being the fact that the primordium of the egg is placed in the apex at the acute side, since in the same point there would be the small umbilical appendix, by which the egg is increased in size, nevertheless we observe that none of the two things is true. In fact the primordium of the egg is not its acute part, but the obtuse one, since in the acute part the chick is not produced, as at proper time it will be shown, and moreover neither in the membranes, and even less in the shell something is found suspended transporting the food into the egg. On the contrary, even more important, there cannot be anything arriving from the uterus to the egg, or fistula, or channel, or vein, or opening linking the egg to the uterus by which it is fed and increased.

Nam cum auctio ovi motui locali coniungatur, et ei quidem longissimo, qui fit deorsum a pulmonibus ad podicem usque, atque is quidem non recta et brevissima linea, sed per [12] multas spiras, et circumvolutiones efficiatur, quomodo poterit appendicula umbilicalis ovo, et utero necti in tam longo, et flexuoso tractu? et cui uteri parti? aut quomodo volutari poterit ovum, aut descendere ad podicem appendicula appensum? sed forte causa erroris Arist. fuit, quod falso existimaverat, ovum respondere semini, et fructui plantarum, qui retro habet suum principium ad ramum, cui appenditur.

Really, since the growth of the egg is linked with the local movement and with that very long occurring downward from the lungs until the cloaca, and that this happens not through a straight and very short line, but through a lot of coils and convolutions, how can a small umbilical appendix merge with the egg and the uterus in a so long and tortuous tract? And with what part of the uterus? Or how can the egg turn over or go down to the cloaca remaining suspended to the small appendix? But perhaps the cause of the error of Aristotle has been to have erroneously thought that the egg corresponds to the seed and the fruit of the plants, which on the contrary has its origin from a branch to which is suspended.

Quod vero in confirmatione sua assumitur, eiectum ovum appendiculam habere probabile est: propterea quod eiicitur ovum violenter, et eiicitur, cum nondum est perfectum; sed vitellus violenter abrumpitur a suo pediculo, ita tamen, ut pediculus sit vitello appensus; in quo casu appendicula visitur, et sanguis, neque potest perfici vitellus abruptus cum sua appendicula, quia non assumit amplius albumen, cum non volutetur. Quae cum ita sint, alio modo dubium diluendum est dicendo, ovum augeri dupliciter, prout duplex est uterus, superior, et inferior; et ovi substantia duplex, vitellus, et albumen, (cum albumine enumerantur quoque Chalazae, membranae, et cortex, quae eandem subeunt rationem cum albumine: Nam haec omnia tum sua natura alba, et frigida sunt, tum ab eodem sanguine pituitoso facta, tum in eodem genita utero) et vero scilicet augmento, et non vero, quod per iuxta positionem fit.

What in his affirmation is claimed is that probably the laid egg possesses a small appendix, since the egg is expelled with violence and is expelled when it is not yet completed, but the yolk is separated with violence from its petiole, nevertheless in such a way that the petiole remains suspended to the yolk. In this case the small appendix and the blood are seen, and the disconnected yolk together with its small appendix cannot be completed since it doesn't receive further albumen, because it doesn't run. Being so the things, we have to solve the doubt in another way, by saying that the egg grows in two ways, since the uterus is double, superior and inferior, and the substance of the egg is double, the yolk and the albumen (with the albumen are also numbered the chalazae, the membranes and the shell, sharing with the albumen the same evaluation; in fact all these things for their nature are white and cold, both produced starting from the same cold blood and generated in the same uterus) and, that is, for a true increase, and for a not true increase happening by proximity.

Vero augmento adaugetur vitellus, non vero albumen. Vitellus enim adaugetur sanguine, qui ad ipsum porrigitur, dum adhuc vitellario, seu racemo appenditur, per venas, quae a mesomitrio per pedunculum sursum ad vitellum porriguntur, et per membranam a pediolo in vitellum porrectam, quae plena venarum est: Et hic vitellus appendiculam habet umbilicalem, quam Arist. στόλον {ὀμφαλώδην} <ὀμφαλώδη> appellat, videlicet pedusculum, et venam quoque umbilicalem, quae per pedunculum fertur: quanquam forte haec non est appendicula, quam Arist. umbilicalem appellat, quod eam non in vitello, sed ad ovi extimam membranam posuerit, ubi, uti dictum est, neque est, neque esse potest.

The yolk grows for a true increase, the albumen for a not true increase. In fact the yolk grows thanks to the blood supplied to it, while it is still suspended to the vitellarium - upper uterus - or cluster, through the veins which from the mesometrium through the pedicle move up until the yolk and through the membrane that from the pedicle stretches in the yolk and which is full of veins. And here the yolk has a small umbilical appendix that Aristotle calls stólon omphalødë - umbilical shaped prominence, that is, pedicle and also umbilical vein which proceeds through the pedicle. Although perhaps this is not the small appendix that Aristotle calls umbilical, since he would have placed it not in the yolk, but near the most external membrane of the egg, where, as it was said, it neither exists nor can exist.

Igitur vitellus vero adaugetur augmento, quod per venas, sanguine, et nutritione completur, quae omnia procul dubio vitellum sensim adaugent vero augmento, quod fit pristina continuitate, soliditateque vitelli corporis servata, donec ad iustam pervenerit magnitudinem: quo tempore relaxatur, resolviturque praedicta membrana a vitello, et vitellus tum in secundum uterum cadit.

Insofar the yolk grows because a true increase occurring through the veins thanks to the blood and the nourishment, all things that without any doubt make the yolk gradually increase with a true increase that happens because of the usual continuity and stability of the body of the yolk, which maintained itself until when reached the correct size. At this point the above-mentioned membrane grows loose and separates from the yolk and then the yolk goes down in the second uterus.

In hoc utero dum degit, cum in suo racemo iam iustum incrementum sit adeptus, non amplius adaugetur: nisi forte modicum quid ex eo, quod in exiguis propriae vitelli tunicae venis remansit. Sed revolvitur albumine, prius Chalazis admissis. Albumen autem alio modo augetur, et accrescit, ac vitellus. Etenim non per venas, neque per nutritionem, ut vitellus, incrementum suscipit: sed per iuxta positionem vitello adhaerescit. Dum enim vitellus per secundum uterum devolvitur, ac sensim volutatur, sensim quoque subinde suscipit albuminis portionem ibi genitam, paratamque, ut circa vitellum apponatur, donec medias spiras vitellus praetergressus, et ad ultimam devolutus una cum ovi albumine circumducto etiam membranis obvolvitur, et corticem assumit.

While being in this uterus it doesn't further grow, since in its cluster it already acquired the correct increase, if not perhaps a modest increase thanks to what remained in the little veins of the proper tunic of the yolk. But it is wrapped by the albumen, the chalazae having formerly developed. But the albumen increases and grows otherwise than the yolk. In fact it doesn't increase through the veins neither through the nourishment, as the yolk does, but it sticks to the yolk by setting itself nearby. Really while the yolk flows down through the second uterus and gradually moves, each time it gradually assumes also the part of albumen here produced and prepared so that it is put around the yolk, until the yolk, after overcoming the coils of the middle part and reaching the last coil together with the albumen of the egg applied around, is wrapped also by the membranes and takes the shell.

Cur vero natura voluerit, ovum partim adaugeri vero, ut in vitello, partim appositivo augmento, ut in albumine; nulla alia ratio est, mea sententia, nisi quia natura in albuminis augmento, non potuit appendiculam umbilicalem constituere, [13] et venam ovo appendere, quam tamen ovi {membrane} <membranae> appensam Arist. posuit[12]. Ratio quod non appendatur vena, et vero augmento augeri non possit reliqua ovi pars, sicuti vitellus, non est alia, meo iudicio, nisi quia; cum tot partes, et tam variae in hac secunda ovi parte gignantur, chalazae, albumen, membranae duae invicem distinctae, et inter se variae, et cortex ab omnibus diversus; et variae uteri partes, forteque etiam proprietates requirantur, et longum etiam spatium; non poterat appendicula constitui, quae tam longa esset, ut sufficeret, et ovum utero coniungeret, propter tractus longitudinem, quem ovum facit per hunc secundum uterum: vitellus autem vero augmento adaugetur, ideo fixus est, non vagus, solutus, et liber, et mobilis, ut albumen; et habet appendiculam, et venam umbilicalem, qualem non habet albumen, quod solutum, et liberum, mobileque est. Haec est ratio incrementi, et absolutionis ipsius ovi, mea sententia.

But why nature wanted that the egg truly partly increases, as it happens in the yolk, and partly increases for an addition, as it happens in the albumen, in my opinion there is no other reason than that nature, when increasing the albumen, has not been able to structure a small umbilical appendix and to attach to the egg a vein, that nevertheless Aristotle has set connected to the membrane of the egg. The reason why a vein is not connected and the remainder part of the egg cannot increase for a true increase, as it happens for the yolk, in my opinion nothing is but because, since in this second portion of the egg are so many and so different structures produced, the chalazae, the albumen, the two membranes separated from each other and different from each other, the shell different from all other structures, and since different parts are necessary and perhaps also different characteristics of the uterus, as well as a wide space, the small appendix could not structure itself in such way to be long enough to connect the egg to the uterus because of the length of the way the egg performs through this second uterus. On the contrary the yolk increases thanks to a true increase, therefore it is fixed, not wandering, loose, free and mobile as the albumen. And it has a small appendix and an umbilical vein that the albumen doesn't possess, being untied, free and mobile. This in my opinion is the reason of the increase and improvement of the egg.

Ad Arist.[13] de eiectis ovis dico, sanguinem in iis duntaxat in vitello apparere, et contineri, ut sensu patet; quem existimandum est extra venas effusum propter casum, aut ictum, aut aliam causam, cum immature vitellus a sua membrana denudatus, separatusque sit. Ideoque vitellus cruentus apparet, non autem albumen. Ultimo loco de ovi cortice dubitandum ex Arist. est. Etenim Arist  et cum eo Plinius dicit[14], corticem non intus gigni, sed cum ovum editum est: atque prout exit, ita ab aere externo obdurari, calore externo evaporante humorem.

To Aristotle, about the laid eggs, I say that in them the blood appears and is contained only in the yolk, as it is clearly visible, and we have to think that it came out from the veins because of the fall, or of a trauma, or of another reason, since the yolk is prematurely bared and separated from its membrane. And therefore the yolk appears bloody, but not the albumen. Finally, according to Aristotle, we have to doubt about the shell of the egg. In fact Aristotle, and Pliny with him, says that the shell is not produced inside, but when the egg has been laid, and that, as soon as it goes out is hardened by the external air, since the external heat does the liquid to evaporate.

Sed ego oculata fide non semel, sed iterum, ac saepius testor, ovum duro cortice obductum intus reperisse, antequam exisset, id quod etiam vos nunc oculata fide videtis in hac gallina. Quod si quis occurrat, in gallina emortua ovum a frigiditate emortui corporis obdurari, simili modo, ac dum exit ab aeris frigido contactu obduratur, ut dicit Arist.: Huic facile respondetur, et in viva gallina ovum duro cortice donatum non difficulter exterius persentiri: id quod mulieres quotidie experiuntur, dum extra abdomen digitis ovi duritiem pertentant, ut cognoscant, an gallina mox sit editura ovum, necne; cognoscuntque id exacte, etiam si ovi duritiem, per mollia corpora superposita, nimirum abdomen pertractent. Audivi tamen a mulieribus fide dignis, non esse ex toto a veritate alienum, ovorum corticem in exitu ab aere obdurari, qui lentum quemdam humorem exeunti ovo circumfusum e vestigio exsiccet, et cortici non dum exacte duro apponat, et induret, id quod fere exemplo fit ut dicit Arist.[15]

But, relying on the eyes, I am witness not only once, but twice and many times, to have found inside the egg covered by hard shell before it came out, a thing that now also you, relying on the eyes, are seeing in this hen. But if someone is objecting that, in a dead hen, the egg hardens because of the cold of the dead body, as is hardened by the cold contact with the air when it goes out, as Aristotle says, to this fellow we easily reply that also in the living hen the egg endowed with hard shell is without difficulty clearly perceived from the outside. A thing that the women daily experiment when, from the outside of the abdomen, they examine with the fingers the hardness of the egg in order to know if the hen will soon lay the egg or not. And they know this exactly even if they touch the hardness of the egg through the interposed soft structures, that is, the abdomen. However I have heard from trustworthy women that it is not entirely foreign to the truth that during the laying the shell of the eggs is hardened by the air, which immediately would dry a certain sticky damp located around the outgoing egg, and puts it above the not yet right hard shell and hardens it, and this happens almost as Aristotle says.

Quod fere non credidissem, nisi ut dixi a fide dignis mulieribus accepissem, atque ego ipse tandem experientia id comprobassem. Nec vero eo inficias, eodem loco, scilicet prope podicem a me quoque ovum aliquando inventum esse putamine destitutum, sed tamen ambabus obvolutum membranis: quod interdum etiam gallinae, licet rarius, emittere solent. In hac igitur difficultate, diu versabar in ea opinione, verum non esse, ovum tunc corticem, et duritiem contrahere, cum excluditur; primo, quia, ut dixi, iam invenitur ovum intus duro cortice donatum: deinde si cortex, obduratum operculum, sive integumentum est separatum, et per se, et a duabus reliquis distinctum membranis, quomodo momento temporis generari poterit?

I should almost not have believed this if I had not learned it, as I said, from faith worthy women, and finally didn't have confirmed it by the experience. In truth I don't deny that in the same point, that is near the cloaca, sometimes also by me an egg without shell has been found, but however enveloped by both membranes, an egg that sometimes, even if very seldom, also the hens usually lay. Therefore about this difficult problem I remained for a long time of the opinion that it is not true that the egg acquires both the shell and the hardness when is laid. First of all because, as I said, the egg is found inside already endowed with a hard shell. Moreover if the shell, the hard coverage or covering, is separated, independent and distinct from the two remaining membranes, how can it be produced in a short time?

Praeterea membranam iam factam contrahere momento temporis duritiem, durum omnino est: insuper cum gallina ovum sine cortice [14] parit, iam membrana mollis servatur, nequaquam obduratur.

Moreover it is very difficult that an already formed membrane quickly becomes hard. Furthermore when a hen lays an egg without shell, then the membrane remains soft and does not harden at all.

Neque vero Aristot. ratio, qua probat, ovum ex utero, molle exire, multum negocii facessebat. Latet nos primo membranam mollem, id esse, quod postremo testa efficitur: perfecto enim ovo, durum ac rigidum evadit, ita modice, ut exeat adhuc molle: dolorem enim moveret, ait Aristot., nisi ita exiret: egressum, statim refrigeratum duratur, evaporato humore quamprimum, qui exiguus inest, relictaque portione terrena. haec Aristot.[16]

In truth the account of Aristotle, by which he demonstrates that the egg goes out soft from the uterus, was not very embarrassing. First of all we don't know if the soft membrane is what later becomes shell. In fact when completed the egg becomes hard and rigid, but so little to go out still soft. In fact it would cause pain, Aristotle says, if it doesn't go out this way. When it went out, immediately cools and hardens, being very quickly evaporated the liquid present in little quantity, and being remained the earthy part. These are the Aristotle's words.

Ad hanc enim non difficulter respondebam primo experientia, quae commostrabat, ovum cum duro cortice exire: deinde ratione quae experientiae astipulabatur. Nam si ex longe angustiore via exit foetus ex utero mulieris, insignis magnitudinis, cur non poterit quoque ovum cum duro cortice ex gallina exire? praesertim cum uterus sit membranosus, et valde extensibilis, et foramen, quod ad podicem est, sit amplum satis, propter quas causas dolorem in exitu inferre effatu dignum minime potest. Unde tametsi non facile exit, alioqui passim suo pondere exiret, saepeque imperfectum, neque sine aliqua exit molestia; tamen dolorem parere alicuius momenti credibile non est, indicio, quod cantat ab emisso ovo gallina.

In fact I did answer easily to this explanation - of Aristotle - first of all with the experience, which clearly pointed out that the egg goes out with a hard shell, then, with an explanation agreeing with the experience. In fact if a fetus of marked greatness goes out of the uterus of a woman through a very narrower way, why also an egg with a hard shell cannot go out of a hen? Above all since the uterus is membranous and very extensible, and the hole turned toward the cloaca is enough wide, that's why during the exit it cannot at all give some pain worthy of mention. Even if it goes out not easily, after all it would go out slowly because of its weight, and often it goes out not completed and not without some bother. However it is not believable that it produces a pain of some importance, as is proof the fact that the hen cackles after laid the egg.

Haec ut dixi, ita probabiliter diu sustinebam, quia tamen ratio omnis quiescat oportet, ubi experientia refragatur: Ideo concedo quoque ego, ovum cortice obductum, et constitutionem inter molle et durum adeptum, iam in exitu statim impensius obdurari; concrescente[17] circa putamen e vestigio, propter humoris evaporationem, ut ait Arist., viscosa ac tenaci quadam humiditate: cum qua madescens in tota superficie ovum nascitur, et recenti cortici adhaerescens exsiccatur, obduraturque, frigido ambiente non nihil interea conferente. Id quod facile intueberis, si gallinam domesticam domi habueris, et ovum ei in exitu dextere manu [arripieris] arripueris.

As I told, I sustained these things for a long time with a lot of probability; but, because it is necessary that any explanation remains quiescent when the experience is opposing, therefore I also am granting that an egg wrapped by the shell, and endowed with a structure between soft and hard, immediately hardens quite a lot when it goes out, because of the immediate thickening around the shell, because of the evaporation of the liquid, as Aristotle says, of a certain viscous and compact dampness, with which the egg soaked in the whole surface is born, and it dries by sticking to the recent shell and hardens, meanwhile being rather useful the circulation of the cold. And you will easily observe this, if at home you will have a domestic hen and with ability you will steal the egg by hand while coming out.

Superest nunc, ut de utilitate actionis, hoc est ovi generationis, aliquid in medium adducamus, seu cuius gratia in pennatis, et nonnullis aliis formatio foetus per ova perficiatur, explicemus.

Now it remains to clarify something about the utility of the activity, that is, of the generation of the egg, that is, to furnish some explanations why in birds and some other animals the formation of the fetus is accomplished through the eggs.

Arist, et cum eo Plinius[18] quinque fere animalium genera enumerant ovum parientia, et ex ovo generationem suam adepta, videlicet pennata omnia: tum quae serpunt, tum testudines, lacertas, et alia quadrupedia propemodum reptantia: item pisces: Item quae pusillo sunt corpore, ut formicae. Haec enim omnia foetus formationem ex ovo obtinuerunt, quorum omnium ratio, seu utilitas neque una, neque vulgaris est. Nam pennata ob eam causam, ex ovo pariunt, tum quod foetus vivus in iis volantibus pondus ingereret, tum quod excrementa foetus una cum foetu fluctuarent huc atque illuc dimota, sicque volatum, praecipuam pennatorum actionem, omnino impedirent, aut difficiliorem redderent, ideoque neque vesica, neque ventriculus, ut quae impense impleantur, et fluitent, neque testes decidui, sed intus omnino positi: neque pulmones penduli, sed costis annexi in avibus conspiciuntur: quin neque pulmones lobos obtinent, neque forte iecur in lobos similiter divisum est, quod ita pendula evaderent viscera.

Aristotle, and Pliny with him, are listing almost five kinds of animals laying an egg and deriving their generation from the egg, that is, all the feathered animals, then those crawling, then the tortoises, the lizards and other quadrupeds more or less crawling, also the fishes, and alike those having a small body, as the ants. Actually all these animals obtained the formation of the fetus from the egg, and the scientific reasons, that is, the utility of all of them is neither only one nor of scarce value. In fact the feathered animals give birth from the egg for the following reasons, both because while flying an alive fetus would add some weight in them, and because the excrements of the fetus together with the fetus would fluctuate being moved here and there, and so they would prevent completely or would make the flight, the principal activity of the feathered ones, more difficult, and therefore in the birds neither the urinary bladder nor the stomach are seen, being things that are very filled and oscillating, nor hanging testicles, but completely located inside, nor hanging lungs, but joint to the coasts. Or rather, neither the lungs are divided in lobes, nor perhaps the liver is likewise divided in lobes, since so they would be hanging entrails.

In summa omne deciduum fluctuans, mobile, librans, aut pondere gravans, natura in volucrum fabrica devitavit. Excipitur tamen vespertilio, qui ut ex Aristot. elicitur et Plinio lib. 10. cap. 61.[19] vivum parit faetum, et volatile animal est. Solvitur ex Arist. quod vespertilio [15] partim volatile, et bipes, partim quadrupes, et terrestre animal est vel potius, dicendum est, utramque naturam mancam habet, quoniam sicuti bipes mutilatum est, ita truncatum quadrupes est, quanvis dentes habeat. Iam vero quae serpunt, reptatuque moventur, et ipsa quoque ova pariunt, quod serpendo, et reptando, terramque contingendo, et affricando, {faetus} <fetus> intus detentus augeretur, non difficulter laederetur, vipera tamen excipitur, quae tum ova, tum vivos edit {faetus} <fetus>, et intra se parit, et similiter, cartilaginei pisces<,> ait Aristoteles.[20]

In short, nature avoided to set anything leaning, fluctuating, mobile, suspended or heavy in the body of the birds. However the bat is an exception, which, as we may gather from Aristotle and from Pliny book X,61, gives birth to an alive fetus and is a flying animal. From Aristotle we may gather that the bat partly is a biped flyer, partly a quadruped and terrestrial animal, or better, we have to say that it possesses both the defective characteristics since, as it is a mutilated biped, as many it is an amputated quadruped, although having teeth. In truth, those animals are crawling like the snakes and moving by creeping, also they lay eggs, since winding and crawling, and touching the earth, and rubbing it, a fetus kept inside would increase and would be injured without difficulty, however the viper is excluded which gives birth both to eggs and alive feti, and produces them inside itself, and in the same manner the cartilaginous fishes, Aristotle says.

Praeterea Testudines ova edunt, quod {faetus} <fetus> intus in ipsis augeri non posset; propter testae duritiem, et rigiditatem undique ipsa obducentem. Item pisces ova edunt, atque ea solis calori exponunt, ob eam causam, ut mas semen in ea inspergat, et faecunda reddat, cum ad coitum non sint idonei, ideoque ut dicit Arist.[21] sese incurrentes attingunt, absolvunturque ocyssime{,}<.> Alia quoque causa est, quod pisces parere multitudinem {faetuum} <fetuum> numerosam debeant; idcirco non intus capiunt, sed exterius per ova pariunt.

Furthermore the tortoises lay eggs, since the fetus remaining in them could not increase because of the hardness of the shell and because of the rigidity it spreads anywhere. Likewise the fishes give birth to the eggs and expose them to the heat of the sun for this reason, so that the male sprinkles the semen above them and makes them fertile, not being suitable for the coition, and therefore, as Aristotle says, they touch each other by chasing each other and immediately separate. Another reason is also the fact that the fishes must give birth to a great crowd of feti, thence they don't keep them inside, but they give birth to them outside by the eggs.

Excipitur piscis canis<,> vulgo{,} Venetiis Asiarius[22], qui tum oviparus, tum viviparus est; propterea quod hic cartilagineus est, et frigidus, atque humidus, et ob frigiditatem mollitiem, et humiditatem molle generat ovum, quod molle existens si extra pareret, periret propter suam mollitiem, ait Arist.[23] quo fit, ut intra se vivum generet, atque hac ratione partim oviparus, partim viviparus sit{:}<.>

An exception is the dogfish, commonly called asiario in Venice, which is both oviparous and viviparous. Insofar, since it is cartilaginous and cold, as well as damp, and because of the coldness, of the softness and of the damp, it produces a soft egg, which, being soft, if the dogfish gave birth to it outside it would die because of its softness, Aristotle says, therefore it happens that it produces it alive inside of itself, and for this reason it is partly oviparous, partly viviparous.

Ultimo formicae, et quae corporum parvitate praedita sunt, ova pariunt tum propter eorum corporis exiguitatem animal intra se continere, et augere non potentem; tum propter faetuum multitudinem, et numerosam earundem sobolem. Sed iam uteri pennatorum utilitates recenseamus.

Finally, the ants and those animals endowed with a small body give birth to the eggs both because of the littleness of their body which cannot contain inside itself an animal and make it to grow, and because of the crowd of the feti and their numerous offspring. But now we examine the utilities of the uterus of the birds.