§. 12.
Dies quartus.

§ 12
Fourth day

Membrana vitelli propria tenuissima facta ampliato blastodermati cedit; hoc jam paene totum obducit vitellum, excepta regione ad ovi apicem, ubi crassum albumen collecto vitello adhaeret.

The proper membrane of the yolk, having become very thin, gives way to the blastoderma which became greater; this already covers almost all the yolk, with exception for the region in proximity of the apex of the egg, where a thickened albumen adheres to the compact yolk.

Copia lactei liquoris vitelli major.

The quantity of the milky liquid of the yolk is greater.

Arteriae et venae supra descriptae majores redditae, sanguine unicolore et intentiori rubedine gaudent.

The arteries and the veins previously described, having become greater, delight in an unicolor and a more intense red blood.

[60] Arteriae membranae vasculosae a venis, quae prius separatim incedebant, jam sub et juxta eas decurrentes comitantur[1].

The arteries of the vascular membrane are accompanied by veins which previously were proceeding separately, and now flowing under them and in their proximity.

Cor in suprema et anteriore regione thoracis se conspectui offert, ita situm, ut [61] apice suo obtuso deorsum, basi sursum respiciat.

The heart offers itself to the sight in the taller and anterior part of the chest, arranged in such a way that with its obtuse apex it is turned downward, with the base upward.

Distinguitur in auricula duplex semi circulus, posterior alter, corporive propior, alter anterior, qui auriculam lunae modo dividit. Haec prima sunt divisionis auricularum initia, quorum sinistra, dextra major, collapsa et tenuibus plicis fere circularibus corrugata apparet et in media sui parte fere semper guttam sanguinis coagulati, per tenuem auriculae membranam transparentem fovet, dextra retro arcum aortae est sita, uti sinistra quandoque sanguine distenta, saepe tamen collapsa invenitur, soletque figura esse fere rotunda; superficie gaudet leviter convexa margineque anteriori crenato[2], incumbitque ventriculo dextro et aortae. In conjunctionem auricularum vena cava se immittit et canalis auricularis, qui versus auriculam angustior, et versus ventriculum magis dilatatus, manifeste in ventriculum descendit. In ventriculo prima novi accrescentis ventriculi vestigia apparent; sub bulbo nempe aortae tuberculum natum, rubellum, ovatum, ventriculo primitivo transversim insidens. Ventriculus sinister figura globosa est. Ex [62] bulbo aortae, ventriculo approximato, duo vel tres adscendunt rami et ex his radicibus aorta antrorsum adscendit, retrorsum porro curvatur arcumque producit descendendo.

In the auricle a double semicircle is distinguished, one posterior or more close to the structure, the other anterior dividing the auricle as being a moon. These are the first beginnings of the division of the auricles <- or atria>, the left of which, greater than the right, appears collapsed and wrinkled by slim almost circular plicae, and in its central part it almost always holds warm a drop of coagulated blood by the thin transparent membrane of the auricle; the right auricle is located behind the aortic arc, sometimes outstretched like the left one by the blood, nevertheless is often found collapsed and its appearance is usually almost round; it enjoys of a slightly convex surface and of an anterior crenate edge, and it overhangs the right ventricle and the aorta. The vena cava gets into the point of junction of the auricles, and the auricular channel, that is more tight toward the auricle and is more dilated toward the ventricle, clearly goes down toward the ventricle. In the ventricle the first traces are appearing of the new growing ventricle; just under the aortic bulb a new tubercle, reddish, egg shaped, transversally leans on the primitive ventricle. The left ventricle is of globular aspect. From the aortic bulb, located near the ventricle, two or three branches are climbing and from these roots the aorta ascends forward, then bends backward and going down makes an arc.

Amnium paene clausum totum fere foetum includit, nempe caput, dorsum, caudam et tubercula alarum pedumque.

The nearly closed amnion shuts up almost all the fetus, that is, head, back, tail and the tubercles of wings and feet.

Plicae abdominales, quae reflexione sua dorsali amnium verum formant, ad foetus latera parallelae dispositae sunt, ad regionem cardiacam vero circa marginem pelvis arcuatim conjunctae limbum formant cavitatis, quae thoracem abdomenque complectitur. Apertura hujus cavitatis primordium est umbilici, nam postea limbus increscit et constringitur, donec ultimum parvum orificium pro larga cavitate abdominis evadit, quod avibus pro umbilico est.

The abdominal plicae, that with their dorsal refolding make the true amnion, are parallely arranged at the sides of the fetus, but toward the cardiac region, joined in an arched way around the edge of the pelvis, they form an edge of the cavity embracing the thorax and the abdomen. The opening of this cavity is the sketch of the navel; in fact subsequently the edge increases and gets narrower, until in place of the wide cavity of the abdomen a last small orifice remains, which serves as navel for the birds.

Ventriculus, ex oesophago ortus, recta via in duodenum descendit, integer est et foveae cardiacae vestigium jam non in ipsum ventriculum sed in duodenum et ex hoc in ventriculum ducit; igitur duodeni cavitas facta est.

The stomach, originated from the oesophagus, goes down in the duodenum by a straight line, it is intact and now traces a vestige of the cardiac fossa, not in direction of the stomach itself, but toward the duodenum and from this toward the stomach; then the cavity of the duodenum is created.

A duodeno intestinum medium incipit et descendit usque ad rectum. Hoc [63] comprehendit in se rudimenta totius intestinorum tractus, qui in adulto corpore duodenum inter et rectum, cui cocca annexa sunt, collocatur. Consistit intestinum medium e duabus laminis marginibus suis posterioribus, conjunctis (suturam intestinalem Wolffius vocat) et in mesenterium continuatis: marginibus autem anterioribus adhuc separatis, revolutis et in membranam vasculosam et pituitosam latera versus abeuntibus.

From the duodenum the middle intestine begins and goes down until the rectum. The middle intestine includes in itself the sketches of the whole section of the intestines, that in the adult body is located between duodenum and rectum, to which berries are attached. The middle intestine is composed by two laminae joined in correspondence of their back borders (Kaspar Wolff calls this as intestinal suture) and they continue in the mesentery: but being the anterior borders still separated, rolled back and withdrawing toward the sides in a vascular and pituitous <- mucous> membrane.

Pone cor pulmones apparent, corpuscula oblonga, fere cylindrica, omnium organorum tenerrima, fere pellucida, inferne subtilissima vesicula terminata.

Behind the heart the lungs appear, lengthened corpuscles, almost cylindrical, the most tender of all the organs, almost transparent, closed below by a very thin vesicle.

Inter cor et pulmonem sub ipsa auricula hepatis lobus dexter situs est, oblongus, curvata superficie anteriori, posteriori, qua cordi incumbit, concava: a parte ejus superiori vena cava recipitur. Lobus sinister angustus, ventriculo et duodeno incumbit.

The right lobe of the liver is located between the heart and the lung, below the auricle itself, it is lengthened, with a bent anterior surface, concave the back one, by which is leaning to the heart: by its superior part the vena cava is held. The left lobe is narrow, leaning to stomach and duodenum.

Miram renes figuram habent, qui proxime ad spinam dorsalem utrinque siti sunt, ejusque ductum sequuntur; lineares fere sunt et longissimi, incipiunt in regione thoracis retro pulmones, et descendunt ad infimam intestini recti extremitatem [64] usque, cui utrinque inseruntur sine conspicuo {urethere} <uretere>. Totius renis structura lamellata, lamellis transversaliter positis, distinctis et vere separatis; quae praesertim in superficie anteriori distincte evolvi possunt, in parte posteriori vero quasi funi cuidam annexae[3].

The kidneys have a marvellous aspect, located at two sides of backbone, and follow its way; they are nearly linear and very long, they begin in the region of the thorax behind the lungs and go down until the lowest extremity of rectum, at two sides of which are inserted without a showy ureter. The structure of the whole kidney is lamellar, with lamellae transversally placed, distinct and very separated; which, above all on the anterior surface, can unwind in a distinct manner, while in the back they are almost attached to a kind of rope.

Pedes alaeque sub tuberculorum specie per amnion transparent. Ala superficie externa convexa glabra gaudet; superficies interna, thoraci applicata, plana, inaequalis, impressionibus eminentiisque instructa est; e margine posteriori eaque crassiori, qua ala corpori affigitur, superius et inferius duae productiones carneae excurrunt, quibus ala corpori firmius adhaeret. Pedum superficies simili gaudent figura. Collo duae appendices basi connatae affixae sunt, rudimenta maxillae inferioris[4]. Maxilla superior sub forma duarum appendicum nondum conjunctarum ad colli curvaturam conspici potest[5].

The feet and the wings shine through the amnion with the aspect of tubercles. The wing enjoys of a convex and hairless external surface; the inner surface, leant on the chest, is flat, not homogeneous, endowed with imprints and prominences; from the posterior and more thick edge, by which the wing sticks to the body, on the upper part and below two fleshy prolongations are stretching out, by which the wing sticks more firmly to the body. The surfaces of the feet enjoy of a similar aspect. To the neck are attached two appendixes produced together in the base, the sketches of the lower jaw. The upper jaw can be observed in the shape of two appendixes not yet joined near the curvature of the neck.

[65] Oculis non multum accedit perfectionis, nisi quod nigredo paullatim choroideam tunicam occupat, quae in hemisphaerio oculi superiori obscurior est. In ea inferiori parte hemisphaerica quasi hilus[6] pellucidus ob defectum choroideae conspicitur.

To the eyes no many improvement is added, apart the fact that the black slowly occupies the tunic of the choroid, which is darker in the upper hemisphere of the eye. In that lower hemispherical part a transparent hilus is almost seen because of a defect of the choroid.

Chorii vesicula, vasis umbilicalibus ornata, volumine aucta est[7].

The vesicle of the chorion, adorned with umbilical vessels, is increased of volume.