[181] EXERCITATIO PRIMA.
Ab ovo gallinaceo cur ducatur exordium.

1st exercise
Why we start from the egg of hen

HIERONYMUS Fabricius ab Aquapendente (quem mihi, ut dixi, praemonstratorem constitui) initio libri sui de formatione ovi et pulli, haec habet: Intentio nostra est de omni formatione foetus agere; initio ab ea, quae ab ovo procedit, desumpto. Haec enim omnem aliam tractationem praecedere debet: tum quia ex hac Aristotelis opinionis intelligentia non difficulter elicitur et habetur; tum quia tractatio formationis foetus ex ovo amplissima est; et altera longe latior et difficilior.

At the beginning of his treatise on the formation of egg and chick, Girolamo Frabrizi d'Acquapendente* (whom, as I said, I appointed as my leader) writes as follows: «It is my intention to treat every formation of the fetus, starting from that one beginning from the egg. In fact this one has to precede every other treatment: both because from this the understanding of the opinion of Aristotle is gathered without difficulty and we acquire it, and because the treatment of the formation of the fetus from the egg is very wide, and much wider and more difficult than another.»

Nos autem ab ovi historia exordiendum duximus, tum ob praedictas causas; tum etiam, quia inde certiora dogmata mutuamur, quae (utpote notiora nobis) quorumlibet animalium generationis contemplationi lucem afferant. Ova enim, cum parvo constent, omnique tempore et loco in promptu sint, facile ex iis observatu est, quaenam sint clara et distincta generationis primordia, quos in formatione progressus natura faciat, et quam admirabili providentia omnia in hoc opere gubernet.

On the contrary, I decided to start from the investigation on the egg, both for the above-mentioned reasons, and also because, starting from the egg, we come into possession of surer data, which (becoming more known to us) throw light on the investigation concerning the generation of whatever animal. In fact the eggs, since they cost little, and in every moment and place they are available, thanks to them it is of easy observation what are the clear and distinct beginnings of the generation, what progresses the nature does in the formation and with what marvellous foresight governs all the things in this enterprise.

Pergit Fabricius: Amplissimam autem esse formationis foetus ex ovis contemplationem ex eo patet, quod maxima animalium pars ex ovis gignitur. Nam, ut insecta ferme omnia et imperfectiora omittam animalia, quae ex ovo fieri sensui apparet, ex perfectioribus quoque maxima pars ex ovis gignitur. Ad hunc censum refert pennata omnia; pisces quoque (praeter sola cetacea) omnes; item crustacea, testacea, et mollia omnia; ex terrestribus, reptilia, multipedia, et serpentia omnia; atque, inter quadrupedia, omne lacertorum genus.

Fabrizi proceeds: «Actually the survey of the formation of the fetus from the egg is very extensive since the majority of animals arises from the eggs. In fact, omitting almost all the insects and the most defective animals that are thought to come from the egg, also the majority of those more perfect arises from the eggs.» In this list he inserts «all the feathered animals; also all the fishes (except the cetaceans only); likewise the crustaceans, the testaceans and all the molluscs; among the terrestrial animals, the reptiles, the myriapods and all the snakes; and, among the quadrupeds, the whole genus of the lizards.»

[182] Nos autem asserimus (ut ex dicendis constabit) omnia omnino animalia, etiam vivipara, atque hominem adeo ipsum, ex ovo progigni; primosque eorum conceptus, e quibus foetus fiunt, ova quaedam esse; ut et semina plantarum omnium. Ideoque non inepte ab Empedocle dicitur[1], oviparum genus arboreum. Habet itaque historia ovi fusiorem contemplationem, quod ex ea generationis cuiuslibet nodus elucescat.

But I affirm (as it will come out from the things which have to be reported) that all the animals, also viviparous, and even the man himself, are generated from an egg, and that their first products of conception, whence the fetuses are coming, are eggs, as also the seeds of all plants. And therefore the expression «arboreal oviparous genus» is rightly used by Empedocles*. Therefore the investigation on the egg has a wider horizon, since the tangle of whatever generation is clarified from it.

Quare de eo primum dicemus, ubi, unde, et quomodo oriatur. Deinde quo pacto, et ordine, quibusque gradibus, foetus sive pullus, in ovo et ex illo, formetur et perficiatur, dispiciemus.

That's why about the egg we firstly will say where, whence and how it originates. Then we will analyse in what way and in what order and in what stages the fetus, or chick, is formed and becomes perfect in the egg and thanks to the egg.

Iterum Fabricius: Animalium foetus, alius ex ovo, alius ex semine, alius ex putri gignitur; unde alia ovipara, alia vivipara, alia ex putri seu sponte naturae nascentia {ἀυτόματα} <αὐτόματα> Graece dicuntur.

Again Fabrizi: «Some fetuses of animals are born from the egg, others from the semen, others from putrid matter; thence some animals are called oviparous, others viviparous, others, born from rotten matter, that is, for a spontaneous act of nature, in Greek are called autómata - spontaneous.»

Mihi vero haec divisio minus placet; cum omnia animalia dici possint quodam modo ex ovo, et quodam modo ex semine oriri; et a partu potius, quam a prima origine, ovipara, vivipara sive vermipara dicantur; quoniam vel ovum, vel vermem, vel vivum animal pariunt. Item sponte nascentia dicuntur; non quod ex putredine oriunda sint; sed quod casu, naturae sponte, et aequivoca, ut aiunt, generatione, a parentibus suis dissimillibus proveniant. Quippe alia etiam animalia, ovum, aut vermem, tanquam conceptum suum et semen, pariunt; ex quo postea, foris exposito, foetum producunt: unde ovipara, aut vermipara appellantur. Vivipara autem dicuntur quia conceptum sive semen tamdiu intra se retinent et fovent, donec foetus inde vivus et formatus in lucem prodeat.

To tell the truth, I don't like a lot this subdivision, since for all the animals it can be said that in a certain way they are born from the egg and in a certain way from the semen, and that are called oviparous, viviparous or vermiparous is because of the way they are given birth rather than from their initial origin, since they give birth to an egg or to a worm or to an alive animal. Likewise they are said to be born spontaneously not because they originate from the rotten matter, but because they originate from the case, for will of nature, and, as they say, from an equivocal generation from parents very dissimilar each other. In fact also other animals give birth to an egg or a worm as being a product of their conception and a semen, from which subsequently, after having been exposed outside, they produce a fetus, thence they are said oviparous or vermiparous. But they are called viviparous since they retain and heat the product of conception or the semen inside themselves until the alive and formed fetus comes to light.