The embryology  of Albertus Magnus

contained in
De animalibus libri XXVI
I Volume - books 1-12
Hermann Stadler – Münster – 1916

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Latin text transcribed by Fernando Civardi
translated by Elio Corti with revision of Roberto Ricciardi
English text reviewed by Elly Vogelaar


It is uncertain when Albertus wrote his Book on the animals, as well as when he wrote his scientific commentaries to Aristotle (384-322 BC), perhaps after his renunciation to the Episcopal chair of Regensburg in 1262. Already toward 1255 Albertus would attend, as main activity, to the annotation of the writings of Aristotle. Other people, but in a less convincing way, are dating this job around 1268.

De animalibus libri XXVI of Albertus is kept in about 40 manuscripts, of which 3 at least of XIII century, 10 of XIV, the others of XV. The more important is without doubt the codex Coloniensis (W 258a of civic archives of Cologne), called C by Hermann Stadler, and that can be regarded as the original writing of the work, because it is the only one offering the complete text (while the other manuscripts and the printed editions suffer from lacunae and omissions), because it is free from many errors of reading (whose presence in the testimonial codices is explained only in dependence from C), and because of the presence of corrections going back to the principal sources of Albertus, that is, Aristotle and Avicenna, showing the activity of the author changing during his work. In the codex C are enclosed other two works of Albertus: De motu et origine animae and De principiis motus processivi.

The style of writing, individual at all, corresponds to the manner of writing in use toward the half of XIII century. According to a tradition dating back to 1483, Albertus was buried in the Convent of Dominicans in Cologne. Here, near a theological work, was found a volumen de naturis animalium de manu sua (just the codex C). These works were brought, from the Convent destroyed during the wars with French at the beginning of XIX century, in the civic archives of Cologne, where they still are. Naturally, as we said, there are other manuscripts of Albertus. The parchment codex C is composed of 429 (in reality 427) sheets; it is written by one hand, with marginal additions (which seem belonging to this hand). Of another hand are perhaps small additions (in critical apparatus Stadler denotes them as m2 and m3). There are many abbreviations not different from the abbreviations of that time. The orthography, as Stadler is observing, is 'consequent in the inconsequence', that is, the same word in the same line can be written in a different way. The punctuation is that in use in the coeval French manuscripts.

Afterwards we remember the codices Basiliensis F 1,19 and F 1,20 (= B of Stadler), the codex Divisionensis M. Nr. 262 of Dijon (= D), both copies of C, the codex Suessionensis Colb. 3 ms. 33 of Soissons (= S). The other codices have lesser importance. As far as the printed editions is concerning, the History of the animals was published in editio princeps (first printed edition) in Rome in 1478, then in Mantua in 1479, in Venice in various reprints between 1490 and 1515. Stadler in his edition tried to distinguish what is pertaining to Albertus from what is coming from his sources, and he employed vertical bars, so that the loanwords are among simple (I) and double bars (II), while the ingredients of Albertus are among double bars (II) and simple (I). For example in IX 69 we find:

I Adhuc autem omnia [Aristoteles et Scotus] II sive quadrupedia sive bipedia sive pedibus carentia [Albertus] I prima [Aristoteles et Scotus] II ante completam quantitatem [Albertus] I tenent capita sua [Aristoteles et Scotus] II in matrice [Alberts] I etc.

Alberts follows the Arabic-Latin translation of Michael Scot (c. 1175 - c. 1235), dealing with zoology in 19 books (10 De historia animalium; 4 De partibus animalium; 5 De generatione animalium). For this he used a reproduction of the Latin codex Vindobonensis 97 (= Sc. in critical apparatus). Stadler supplies in apparatus the lost names of the Greek animals, that Albertus is changing in his text so that they are incomprehensible. Of Avicenna Albertus uses the Canones in his anatomical books, as also the extracts of the De animalibus of Aristotle, while Galen (129/130 - 199/201) is indirectly quoted by him through Avicenna (980-1037), whose at his times circulated Latin versions, afterwards printed.




Incipit liber sextus de animalibus de natura et anathomia et generatione ovorum, cuius tractatus primus de alteratione et diversitate est ovorum.

The sixth book of animals begins on nature, anatomy and generation of eggs, and the first item is concerning the differentiation and the diversity of eggs.

Cap. IV.

De tempore completionis ovorum et de anathomia eorum et mutatione in formam pulli.

Chapter IV

About the time needed to the completion of the eggs and their anatomy and the transformation in chick.

[24] Genera autem pullorum diversantur secundum tempus cubationis et anathomiam ovorum. Ovum enim gallinae fecundum, quod a semine galli concipitur, ab undecimo die seminis concepti completur in quantitate et figura ad emissionem ovi ut frequentius, contingit tamen in gallinis duplex ovi conceptus. Unus quidem est a semine galli, quod primum intra matricem concipitur et attrahit materiam ovi et format eam, sicut semen gressibilium generantium sibi simile attrahit materiam conceptus: et ille conceptus et formatur et perficitur ad ovi perfectionem ut frequentius in diebus undecim. In gallina tamen iuvene cicius completur quam in antiqua, et in climate calido cicius quam in frigido: et in ea quae utitur nutrimento calido, cicius completur quam in ea quae utitur nutrimento frigido: et sic est de aliis accidentibus considerandum, quae complexiones variant gallinarum.

[24] The birth of the chicks differs according to incubation's duration and eggs' anatomy. In fact a fertile egg of a hen, conceived thanks to the seed of the rooster, starting from the eleventh day from seed's reception it completes itself in volume and aspect for the coming out of the egg, as it happens more frequently. Nevertheless in hens a double conception of the egg is happening. A conception comes from the seed of the rooster, that is received as first in the uterus and it attracts the matter of the egg and gives it a shape, as the seed of breeder walking animals attracts the matter of conception similar to it: and such conception happens and completes until the completion of the egg mainly in eleven days. Nevertheless in the young hen it is completed more quickly than in the old one, and in a warm climate more quickly than in a cold one: and in the hen using a warm food it is completed more quickly than it happens in the hen using a cold food: and in the same way we have to consider about the other happening things making to vary the constitution of the hens.

[25] Alius autem conceptus est, quando sperma galli receptum invenit materiam ovi venti in matrice aut in parte aut in toto praeter pellem et testam completam: tunc enim sociatur ei et fecundat item ovum et immutat, et hoc ovum cicius ovatur secundum quod magis vel minus materiam in matrice praeparatam invenit. Aliter enim est de avibus et aliter de animalibus. Aves enim aliquando retinent intra se materiam ovorum diucius, et aliquando emittunt tardius: et hoc apparet in avibus, quibus auferuntur ova. Illae enim post modicum ovant alia, quae retinerent, si ova priora eis ablata non fuissent: et probabile est quod coitus, quem iterant amissis ovis, ad haec cooperetur: sed tamen, nisi haberent quasi in thesauro ovorum materiam, non ita cito ovarent post amissionem ovorum: et quando non amittunt ea, non coeunt: et ideo non complentur, et forte consumitur materia eorum per calorem famis et calorem naturalem.

[25] Moreover a different manner of conceiving occurs when the sperm of the rooster when has been accepted finds in the uterus the matter of the windy egg partly or entirely completed, except the membrane and the shell: in fact then the sperm joins the matter and at the same time it fertilizes the egg and makes it to change, and this egg is laid more quickly according to whether it finds more or less ready material in the uterus. In birds and in animals the things occur in a different way. In fact sometimes the birds hold the material of the eggs for a longer time inside of themselves and sometimes they send it forth more belatedly: and this is visible in birds whose eggs are removed. In fact soon after they lay others, and they would hold them if the previous eggs had not been removed: and it is probable that the coition, that they reiterate after having lost the eggs, cooperates to this purpose: nevertheless if they didn't have, so to say, treasured the matter of the egg, they would not lay so early after having lost the eggs: and when they don't lose them they don't mate: and therefore they don't become pregnant, and perhaps the matter of the eggs exhausts through the heat of the hunger and the natural heat.

[26] Feminae autem pavonum et columbarum et plurium aliarum avium osculantur ante coitum propter libidinem, ut cicius pruritum inducant per confricationem, ut superius diximus: et in tempore libidinis aliquando femina saltat super feminam, quando deest eis mas, sed non concipit ex hoc ovum fecundum, sed potius ovum venti, eo quod per confricationem sola substantia materialis ovi ad matricem congregatur: sed quando osculatur marem, tunc post modicum excitata libidine mas ascendit super feminam et coit et fecundat ova ipsius. Sed tamen pavonis femina et columbae in hoc habent differentiam, quoniam mas columbus non utitur ad coitum columba tempore, quo fovet ova e quamdiu parvuli sunt columbi: pavo autem mas etiam tempore quo femina fovet ova, utitur ea ad coitum: et ideo locum, in quo cubat pava ova sua abscondit a pavo: quia coeundo super eam frangit ea. Dixit tamen michi quidam valde expertus circa pavones, quod ex zelo pavonis contingit fractura ovorum: pugnant enim tunc pava et pavo pro incubatione ovorum ex nimia ovorum dilectione: sicut etiam pro pullis ducendis pugnant grus masculus et grus femina: ita quod vidimus oculis nostris gruem marem deicere feminam gruem et occidere rostro undecim vulneribus sibi datis, eo quod pullos abstraxit a mare, ne sequerentur eum: et hoc accidit in Colonia, ubi sunt grues domesticae pullificantes.

[26] Because of the lust, the females of peacocks and doves and of many other birds are kissing before coition, with the purpose to induce more quickly the excitement through the rubbing, as we previously told: and in the period of sexual desire sometimes a female climbs on a female when they are without male, but from this fact she doesn't conceive a fertile egg, on the contrary a windy egg since in the uterus is gathering only the substance compounding the egg. But when she kisses the male, then soon after, the lust having been excited, the male climbs on the female and mates and fertilizes her eggs. Nevertheless the peacock's and dove's female shows a difference, since the male of dove doesn't use for coition the time in which the female is brooding the eggs and until the doves are rather small: on the contrary the male peacock uses the female for coition also in the time she is brooding the eggs: and therefore the female peacock conceals from the male the place where she is brooding her eggs: because when mating by being above her he breaks them. Nevertheless a man very experienced about peacocks told me that because of the jealousy of the peacock it happens that the eggs are breaking: in fact in that period the female and male peacock because of the excessive love for the eggs fight with the purpose of brooding the eggs: as also the male and the female of the crane fight for raising the chicks: so that I have seen with my eyes a male of crane knocking down a female and killing her with eleven wounds he gave her with the beak, since she had taken away the chicks from the male so that they didn't follow him: and this happened in Cologne where domestic crane are giving birth to chicks.

[27] Generatio autem pullorum quantum ad ipsam ovi transmutationem et anathomiam est fere secundum unum modum in omnibus avibus magnis et parvis, et hoc ostendemus in ovis magis notis, quae sunt ova gallinarum, de quibus sciendum, quod habent tres pelliculas universales, quarum una est, quae interius coniungitur testae, quae fere est sicut dura mater in capite hominis: et altera est intra illam, quae continet albuginem: quae est sicut pia mater cerebri humani: et hoc apparet in ovis antiquis, quae resederunt aliquantulum a testa retracta: in hiis enim etiam oculo praedictae apparent pelliculae. Tertia vero est, quae includit vitellum ovi.

[27] The generation of the chicks, as far as modification and anatomy of the egg is concerned, occurs almost in only one way in all big and little birds, and we will illustrate it in the more known eggs that are the hens' eggs, apropos of which we have to know that they have three membranes identical in all the eggs, one of which is that sticking inside to the shell and which practically is like the dura mater lying in the head of human beings; the other one is lying at its inside and surrounds the albumen, and which is like the pia mater of human brain: and this is visible in old eggs that moved back a little bit from the shell which withdrew: in these eggs in fact the above-mentioned membranes are equally visible. The third membrane is that containing the yolk.

[28] In gallinis igitur, postquam ova cubaverint per tres dies, statim apparet ovi ad formam pulli mutatio: tamen in maioribus avibus erit hoc post plures dies: et in minoribus avibus, quam sunt gallinae, erit hoc post pauciores dies proportionaliter pensata quantitate. In spatio enim trium dierum in gallinis ascendit citrinum ovi versus acumen ovi, eo quod ibi est maior calor et vis spermatis, et trahit ad se materiam cibalem, unde accipit supplementum carnis, quam ponit inter nervos et venas, sicut supplementum accipit formativa, quae est in spermatibus animalium generantium sibi similia, ex sanguine menstruo: propter quod etiam caro pars materialis est, quae influit et effluit per augmentum et diminutionem et pinguedinem et maciem.

[28] Therefore in hens, after they brooded the eggs for three days, immediately appears a change of the egg that takes the shape of a chick: nevertheless in bigger birds this will occur after a greater number of days: and in birds smaller than hens this will occur after a lower number of days proportionately to the correspondent volume. In fact in hens within three days the yellow moves toward the acute end of the egg, since here the heat and the strength of the sperm are greater, and it attracts the nutritional material toward itself, from which it receives an increase of the flesh it places between the nerves and the veins, so as the structure present in the sperms of the animals producing beings similar to them starting from the menstrual blood, undergoes an increase: that's why also the flesh is a portion of matter penetrating and coming out through an increase and a decrease, a fatness and a thinness.

[29] Sic autem ascendente citrino ad acumen ovi continue ascendit tractum ad illum locum ovi, ubi apparet fissura in testa, quando egreditur pullus: haec enim fissura fit in superiori parte ovi versus acumen[1], ubi formatur caput et rostrum avis: et ibi postquam ascendit citrinum, apparet in albo ovi quasi gutta sanguinis: et illa gutta primitus inter membra formatur in cor avis, quod statim ut formatur, spiritu plenum est ex calore digerente et formante humidum, in quo spiritu vehit se virtus formativa in formationem aliorum membrorum ex corde: qui exitus spiritus a corde non fit nisi per motum cordis secundum systolen et dyastolen, et ideo cor tunc movetur: sed a principio est lentus motus eius propter multum humidum, quod est in ipso, quod cito a calore vinci non potest. Motus autem hic relinquit supponens animam sensibilem: licet non tunc insit ut actus corporis organici physici, sed sicut artifex in artificiato faciens et instituens organa, in quibus expleat vitae potentias. De hoc tamen in sequentibus cum de generatione hominis agetur, erit aptior locus inquirendi.

[29] And so the yellow, moving toward the acute end of the egg, continually moves being attracted toward that zone of the egg where a crack appears in the shell when the chick comes out: in fact this crack occurs in the upper part of the egg toward the point- not! towards the blunt end, where the head and the beak of the bird is formed: and in this point, after the yellow moved aloft, in the white of the egg something is appearing similar to a drop of blood: and such drop firstly takes shape structuring itself in the heart of the bird, and as soon as it is formed it is full of vital strength coming from the heat distributing and giving life to dampness, and in this vital strength the formative ability transfers itself to compose the other structures starting from the heart: and this out coming of the vital strength from heart happens through a movement of the heart relying on systole and diastole, and therefore then the heart moves: but initially its movement is slow because of the great damp present in it, since the damp cannot be quickly overwhelmed by heat. But the heat allows the movements, adding a perceptible breath: although in this period is not present something similar to the push of a physical organic body, but something similar to a craftsman that in a laboratory creates and prepares some instruments in which he accomplishes the potentialities of the life. Nevertheless it will be a better moment to investigate this when later the generation of the human being will be discussed.

[30] A gutta autem sanguinis, ex qua cor formatur, exeunt duae viae quasi venales et pulsatiles: et est in eis sanguis purior, ex quo formando sunt membra principalia sicut epar et pulmo et talia: et illae viae primo sunt valde parvae et crescunt continue, ita quod extenduntur usque ad telas illas exteriores, quae totam includunt ovi materiam, et ibi incipiunt ramificari divisione multa: sed una maior earum apparet in tela, quae includit ovi albuginem: illa enim albugo primo valde est alba, et per venae illius virtutem mutatur quasi in palearem colorem: et tunc via, de qua diximus, procedit ad locum, in quo formatur caput pulli, portans illuc virtutem et puriorem materiam, ex quibus caput formatur et cerebrum, quod est medulla capitis: et in formatione capitis formantur etiam oculi, et quia sunt ex humido aqueo, quod vix completur calore primo, sunt valde magni turgentes ante caput pulli, et postea modico tempore resident aliquantulum et deturgent diminuti propter caloris digestionem: et hoc totum operatur virtus vecta per viam, quae directa ad caput separatur et ramificatur a vena continente telam albuginis: et huius signum est, quod qui frangit ovum in illo tempore, inveniet caput apparere in humore ovi absque omnibus aliis inferioribus membris.

[30] From the drop of blood from which the heart is forming two ducts go out similar to veins and pulsating: in them purer blood is present from which have to form the principal organs as liver and lung and similar: and at first these ducts are very small and continually grow, so to stretch until those external tissues containing the whole substance of the egg, and here they start to branch through many subdivisions: but one of them appears greater in the membrane containing the albumen: in fact that albumen at first is very white and thanks to the power of such vein it almost turns into straw colour: and therefore the duct of which we have spoken goes towards the area in which the head of the chick is forming, bringing there energy and purer material from which the head and the brain are forming, being the latter the inner part of the head: and while the head is forming also the eyes are forming, and being that they originate from a watery dampness which barely disappears at first heat, they appear very big and turgid in the anterior part of chick's head, and subsequently they shortly stop a little bit and go flat since they decrease because of heat's absorption: and all this is producing the strength transported through that way which directed toward the head separates and branches from the vein containing the membrane of the albumen: and this is confirmed by the fact that he who breaks the egg at that time will find that the head appears in the liquid of the egg except all other structures placed beneath.

[31] Prius enim in formatione pulli apparent partes superiores, eo quod sunt spirituales et nobiliores factae ex subtiliori parte ovi, in qua magis potuit vis formativa: et tunc hoc facto una duarum viarum, de quibus diximus, quod a corde oriuntur, ramificatur in duo: et una quidem pars eius vadit ad spiritualia, quae cor {ocntinent} <continent>, et dividitur in eis portans eis pulsum et subtilem sanguinem, ex quo pulmo et spiritualia formantur: et alia extenditur per dyafracma, et in extremitate sua claudit in se citrinum ovi: et circa illud format epar et stomachum: et ideo ista dicitur habere vicem umbilici in animalibus, quoniam per illam trahitur nutrimentum in supplementum carnis, quae formatur in corpore avis: principium enim generationis radicalium membrorum pulli est ex albugine: sed cibus, unde fit caro supplens vacuitates, est ex vitello.

[31] In fact during the formation of the chick the upper parts appear at first being spiritual and more noble, being constituted by the most delicate part of the egg in which the formative strength had a greater power: and then, once this happened, one of the two ducts, we said to originate from heart, branches in two parts: and one of its portions quickly advance toward the spiritual things containing the heart, and the former subdivides in them bringing them a pulsation and not very thick blood from which the lung and the respiratory structures are forming: and the other portion stretches through the diaphragm, and at its extremity it contains in itself the yellow of the egg: and around the latter it forms the liver and the stomach: and therefore this part is said to have the function of the navel of animals, since through it the nourishment is assumed for helping the flesh's growth that is forming in the body of the bird: in fact the principle of the generation of the sketches of chick's organs originates from albumen: but the food from which the flesh closing the voids is formed, comes from yolk.

[32] Et quando sic transierint decem dies a principio cubationis, in quibus huiusmodi fiunt distinctiones membrorum, erit pullus complete lineatus in omnibus membris suis, licet adhuc membra eius sint humida mollia: sed tamen omnes partes eius apparent manifeste, si frangatur ovum: et caput suum tunc est secundum apparentiam maius toto corpore, eo quod humidum medullare cerebri adhuc non resedit: propter quod etiam in infantibus hominum capita etiam post generationem sunt aperta, donec exsiccatum paulatim fuerit cerebrum: et in eodem tempore oculi pulli non habent visum aliquem, eo quod non adhuc coadunatum est in eis humidum: et si quis discooperuerit a tela palpebrae oculos in illo tempore, inveniet oculos nigros magnos, ita quod quantitatem fabae aequant vel forte excedunt: et si frangatur tunica oculi, emanat ex eis humiditas alba, frigida valde et aquea: et nichil duriciae vel glandulositatis invenitur in illa, eo quod non adhuc adunati fuerint humores oculi.

[32] And so when ten days will be passed from the beginning of the brooding, when such differentiations of the organs are occurring, the chick will be entirely sketchy in all its organs, although its organs are still damp and soft: nevertheless all its parts are clearly visible if the egg is broken: in this moment its head appears greater than the whole body, since the damp marrow of the brain has not yet stopped: that's why also in the newborns of humans, also after they are born, the head remains open until the brain will have dried a little: and always in this moment the eyes of the chick don't have any visual ability since the dampness has not yet assembled in them: and if someone in this moment freed the eyes by opening the membrane of the eyelids, he will find some big black eyes, so big to match or perhaps to overcome the size of a broad bean: and if the membrane of the eye is broken, a white fluid escapes from it, very cold and watery: and nothing of hard or of glandular is found in it, since the liquids of the eye have not been yet assembled.

[33] Sed interiora instrumenta viscerum in illo tempore manifesta sunt in pullo: et tunc apparent etiam viae venales, quae extenduntur a corde ad oculos per telas capitis, et illae habent quosdam ramos, qui se extendunt ad citrinum, ex quibus nutrimentum apportatur oculorum. Et in hoc tempore citrinum est magis humidum et liquidum, quam sit, quando est in esse naturali ante cubationem: et hoc ideo fit, ut aptius possit fluere per subtiles vias venarum: et tunc multum ramificantur venae, et quaedam earum vadunt ad telam, quae continet totum pullum et quaedam vadunt ad telam vitelli afferentes cibum et quaedam etiam vadunt ad humiditatem albuginis, quae est inter duas telas dictas: et crescente quidem pullo paulatim et paulatim dividitur citrinum, et erit una pars eius sursum in nutrimentum superiorum et alia deorsum ad inferiorum nutrimentum: in intermedio autem duorum citrinorum est alba humiditas, quae est radicalis humiditas membrorum in intermedio illo formandorum. Similiter autem sub citrino, quod nutrit inferiora, descendit albus humor, qui est sicut primus humor ovi, qui est radicalis inferioribus membris: et cum transeunt decem dies a perfecta pulli formatione, de qua diximus, erit inferius in corpore pulli totum album, et de eodem album paucum spissum quoddam declinans est versus citrinum, per quod sugitur nutrimentum: et haec quidem est pulli formatio.

[33] But in the chick the inner set of the entrails is well visible in such period: and in this moment also the venous ways are visible, extending from heart to eyes through the head's membranes, and such ways have some branches reaching the yolk, and through them a nourishment is brought to the eyes. And in this period the yolk is more damp and liquid than it naturally is before incubation: and therefore this happens so that it can flow more easily through the thin venous ways: and then the veins are branching a lot and some of them proceed up to the membrane containing the whole chick and some go to the membrane of the yolk since they bring food and rather some push forward to the albumen's liquid laying among the two above-mentioned membranes: and while the chick slowly grows, also the yolk gradually subdivides, and one part of it will be aloft and will serve as nourishment of upper parts and the other one will be downwards to feed the inferior parts: in the part interposed to the two portions of yolk the dampness of the albumen is present, that is the fundamental dampness of the organs that have to form in such area. Likewise the white liquid goes down below the yolk nourishing the inferior parts and such liquid is, so to say, the first liquid of the egg and represents the root of the lower organs: and when ten days passed since the formation of the chick is completed, about which we have spoken, the whole albumen will be in the lower part of chick's body, and a little bit of this not much dense albumen is going towards the yolk, through which the nourishment is sucked: and this is the formation of the chick.

[34] Situs autem telarum est secundum istum modum, quem dicemus. Prima quidem tela, quae quidem non est testa, sed quasi dura mater defendens substantiam ovi a testa, est in posteriori parte ovi interius per circuitum contingens testam. Alia autem, quae est sub ista sicut pia mater, habet intra se albam rem humidam, ex qua fiunt substantiae radicales membrorum pulli: et ipsa in generatione est quasi secundina[2] continens totum pullum. Inter telam autem et telam est humor indigestus, qui reicitur in formatione pulli: et tela interior separat pullum ab humido illo, quia in ipso impediretur formatio et completio eius: et post istas ambas telas invenitur citrinum in tela quadam sub pullo, inferius situm versus naturalia pulli, remotum a spiritualibus ipsius partibus, et sicut diximus superius, ad citrinum illud vadit una vena loco umbilici existens et alia vadit ad telam continentem pullum. Et ista omnia sunt intra telam exteriorem, quae sicut dura mater est, et cum hiis humidum, quod est sicut virus, quod reicitur et tenetur intra duas telas exteriores usque ad exitum pulli.

[34] The layout of the membranes is in the way we will say. The first membrane, that in reality it is not the shell, but almost a dura mater protecting the substance of the egg from the shell, in the back part of the egg - at the obtuse end - is arranged more inside through a circular formation that is in touch with the shell. The other membrane, laying under this as being the pia mater, shows inside a damp white substance from which the sketches of chick's organs are forming: and still this membrane during the generation behaves almost as a secundine containing the whole chick. Between one membrane and the other there is an undigested liquid that is excluded during the formation of the chick: and the most inner membrane separates the chick from this liquid since in it its formation and completion would be prevented: and after both these membranes the yolk is found, inside a membrane below the chick, located beneath toward the genital organs of the chick, far from its respiratory parts, and, as we said before, a vein goes towards this yolk acting as navel and another goes towards the membrane containing the chick. And all these things are inside the external membrane which is as the dura mater, and along with them the liquid that is like a poison pushed away and kept among the two external membranes until the coming out of the chick.

[35] Post illud enim humidum est alia tela vice piae matris et secundinae, quasi ipsa intendat separare pullum ab illo relicto humido et reiecto. Et sub isto humido, quod in se continet haec tela, invenitur citrinum coopertum in alia tela, ad quod extenditur umbilicus a corde, sicut diximus. In vicesimo autem die completam habet vitam pullus, et si moveatur ovum, quasi auditur interius fistula et sibilus pulli. Si autem frangatur ovum intra decimum diem formationis pulli, invenitur caput eius supra crus dextrum ipsius, et supra myrach complicatum, et alae eius complicatae supra caput ipsius: et in isto tempore tela exterior est sicut corium quoddam positum supra telam interiorem, quae sequitur eam, ad quam superius diximus extendi unam duarum venarum a corde ramificatarum: et ista tela, quae est post exteriorem, est in qua invenitur pullus.

[35] Beyond that liquid there is another membrane acting as pia mater and secundine, almost wishing to separate the chick from that refused residue of dampness. And under this liquid that this membrane contains in itself, there is the yolk, covered by another membrane, which is reached by the navel starting from the heart, as we said. On the twentieth day the chick has a complete vitality and if the egg was moved, the whistle and the hiss of the chick at its inside would almost be heard. If then the egg is broken around the tenth day of chick's formation, its head is found placed above its right leg and refolded above the diaphragm, and its wings refolded above its head: and in this moment the outer membrane is as a leather laying on the inner membrane that goes toward that we previously told is connecting one of the two veins branching from the heart: and this membrane, that is found after the external one, is that in which the chick is found.

[36] Adhuc autem apparet etiam alia tela similis corio membranali, quae continet citrinum, ad quam diximus aliam venam cordis extendi. In isto enim tempore, quod est formationi pulli deputatum, venit umbilicus ex parte exteriori istius tertiae telae extensus a corde ad coreon[3], quod est tela membranalis: et pars {eius dem} <eiusdem> venae, quae est vice umbilici, apparet quasi continuata cum pullo aput intestinum involutum gracile, quod est sub stomacho, per quod sugitur quasi per meseraicas nutrimentum. Et isto tempore pullus emittit superfluitatem valde humidam extra inter duas telas, de quibus diximus, per foramen interioris telae versus anum pulli factum. Aliquando autem aliquod parvum superfluum eiciendum retinetur in eius interiori sub tela interiori: et est illa superfluitas alba, tenuis et intus et extra.

[36] Besides the other membrane also appears similar to thin leather containing the yolk, and to which we said to stretch the other vein of the heart. In fact in this time's interval, devoted to the formation of the chick, the navel coming from the external part of this third membrane stretches from the heart to the chorion which is a thin membrane: and a part of the same vein, that acts as a navel, appears almost in continuation with the chick near the thin curled up bowel that is under the stomach, through which bowel the nourishment is sucked as if happening through mesenteries. And  in this period the chick sends forth a very damp overabundance among the two membranes, of which we have spoken, through a hole of the inner membrane toward the chick's anus that is formed. In fact sometimes a little superfluous quantity, that has to be sent out, is kept at its inside under the inner membrane: and it is that white superfluous quantity, thin both inside and outside.

[37] Cum autem completur pullus, primo quidem citrinum est multum et apparet etiam in exitu pulli in ventre eius multum citrinum, et postea efficitur paucum: et cum tempus processerit et perfecte corroboratur pullus, dissolvitur totum citrinum, ita quod nichil apparet de ipso. Si quis enim pullo iam completo et perfecto findat testam et findat etiam intestinum, quod vicinatur citrino pulli, et venam, quae est vice umbilici, in ventre quidem venae inferius, in quo ambit citrinum, inveniet adhuc aliquid de citrino, sed residuum iam dissolutum est. Ante tempus autem illud pullus in ovo est quasi dormiens propter multum humidum capitis eius: et tremunt oculi eius, eo quod non adunatum habent visum, et non vociferat propter debilitatem et molliciem organorum suorum: sed in suis oculis et in suo corde propter venas pulsantes invenitur ampulla elevata et depressa a spiritu pulsante, quasi sit anhelans.

[37] When the chick is completed, at first the yolk is quite a lot and also during the out coming of the chick a lot of yolk is present in its abdomen, and later it becomes little: and  with the passing of time and with the chick growing stronger the whole yolk dissolves, so that no more is seen in it. In fact if someone, when the chick is by now completed and finished, would break its shell and also would split the bowel that is near the yolk of the chick, as well as the vein carrying out the task of navel, inside the abdomen, set below the vein, in which the yolk moves, he will still find some yolk, but the remainder already disappeared. In fact before that time the chick is like sleeping in the egg because of the lot of dampness of its head: and its eyes are trembling since they are not able to see, and it doesn't send forth any voice because of the weakness and the softness of its organs: but in its eyes and in its heart because of the veins that pulsate, is found an ampulla tall and low because of the pulsations due to the breath, almost gasping.

[38] Iste igitur est modus generationis pulli. Multa tamen sunt ova non quidem venti, sed coitus, infecunda, ex quibus nichil generatur, sicut in antecedentibus diximus: et quando illa ova cubat gallina, non pullificant omnino: et similiter est in aliis avibus secundum proportionem ad ova gallinarum. Apparet autem hoc praecipue in columbis, in quibus saepe invenitur alterum ovorum non pullificare, cum tamen columbae multum coeant.

[38] This is therefore the way the chick is begot. However the infertile eggs are a lot, not the windy ones, but those from coition, from which nothing is born, as we previously told: and when the hen broods those eggs, they don't produce chicks at all: and the same happens in the other birds by the same token it happens to the eggs of the hens. This occurs especially in the doves in which it is often found that one of the two eggs doesn't give chick, despite the doves are mating quite a lot.

[1] Questo č un grave errore di Alberto. La testa del pulcino č diretta verso la parte ottusa dell'uovo, dove c'č la camera d'aria. Vedi il lessico alla voce Embrione di pollo.

[2] Secundae (membranae), (membrane) che escono per seconde, cioč dopo il feto. La placenta e gli altri annessi fetali.

[3] Corion deriva dal greco chórion che significa membrana dell'uovo, ma anche placenta, membrana che avvolge il feto.