[270] EXERCITATIO VIGESIMA.
Inspectio sexta.

20th exercise
The sixth inspection

DIE septimo omnia manifestiora sunt, visunturque singularum partium primordia: nempe alae, pedes, genitalia, pedum digiti divisi, femora, clunes, et caetera. Iam se movet foetus et calcitrat, perfectusque pullus conspicitur; cui nihil postea superadditur, sed partes tenellae duntaxat incrementum sumunt: quae quanto magis augentur, tanto quoque magis albumen absumitur; membranaeque exteriores unitae, secundinae[1] naturam referunt; quemadmodum et venae umbilici effigiem magis indies repraesentant. Quapropter a die septimo ad decimum transiliendum censeo; cum interea temporis nihil observatu dignum occurrat, quod non passim apud auctores alios, praesertim Aristotelem, reperias.

On the seventh day all the things are more evident and the sketches of the single parts are seen: that is, wings, feet, genitals, subdivided toes, femurs, buttocks et cetera. The fetus already stirs and kicks, and a completed chick is seen, to which afterwards nothing is added, but only the more delicate parts become greater, and as much as they increase, so much more albumen is consumed, and the united more external membranes have the aspect of the secundine, likewise also the veins day by day recall more and more the aspect of the navel. That's why I think to jump from the seventh to the tenth day, since in the meantime nothing occurs worthy of consideration, and that you would not find in any point among the other authors, above all Aristotle.

Fit tamen, ut plura simul ova inspicienti, quaedam praecocia et provectiora, omniaque explicata magis habentia; alia tardiora, membrisque minus distincta appareant. Quanquam alias non parum ad hanc rem faciunt anni tempus, locus, externa fomenta, diligens incubatio, et si quae sunt alia huiusmodi. Memini me aliquando, die septimo, in ovo ignaviore vidisse cavitatem quidem in obtuso cacumine dilatatam, colliquamentum venis conspersum, in eius medio vermiculum, oculi etiam rudimentum, caeteraque quae in aliis ovis quarto aut quinto die fieri solent: vesiculae tamen pulsantes non aderant; nec venarum truncum, aut radicem, ex qua ipsas oriri diximus, reperire licuit. Quapropter merito ovum imbecillius [271] iudicabam, et quasi a tergo relictum, facultateque generativa effoeta praeditum, iamque internecioni proximum. Praesertim, cum eius colliquamentum minus solito pellucidum et fulgens, venasque parum rutilantes cernerem. Evanescente nempe spiritu vitali, pars quae in generatione prima efficitur et sub obtutum cadit, in corruptione quoque prior deficit et evanescit.

Nevertheless it happens that for him who contemporarily inspects many eggs, some are precocious and more advanced, and have all the structures more evident, others are more belated, and they appear less distinct regarding the various structures. Even if on the other hand to this are quite contributing the period of the year, the place, the external heats, the scrupulous incubation and other such things supposing that they exist. I remember once to have seen at the seventh day in a rather slow egg the cavity of the obtuse side being dilated, the colliquation was covered by veins, at its centre there was a little worm, also a sketch of the eye, and the remaining things usually present in the other eggs at forth or fifth day. Nevertheless there were not the pulsating vesicles, neither it was possible to find the trunk or root of the veins from which I said that they take origin. Therefore rightly I judged it an egg rather weakened and almost set apart, and endowed with a very weak generative power and by now near the death. Above all because I saw that its colliquation was less transparent and shining than usual and that the veins were little red. With the fading just of the vital spirit, the first part created during the generation and falling under the sight, in case of corruption it is also the first ceasing and fading away.