Sed quaerat modo hic quispiam qua ratione cognoscatur, si quid ex illis nasciturum sit. Certa quidem illius indicia statuere difficillimum esse puto. Tradit tamen Albertus ova incubationi idonea quarto die sanguineas habere venas: eo itaque tempore ad solis radios examinari possunt, et in quibus venae apparent, rursus supponi, alia minime. Videat autem, quisquis introspexerit, si eadem die in acutiore parte clara appareant, hoc est, ut Plinius[1] loquitur, cum purus, et uniusmodi pelluceat color; nam talia ad generationem inepta sunt; item in quibus Galli semen tunc non apparet, teste Varrone[2]. Albertus septimo rursus die inspici iubet, et si quid est, quod Soli obtentum non videatur alteratum, abijci, ceu subventaneum, et inutile. Sed in eiusmodi exploratione ovorum observandum maxime est, ut caveat inspector summopere, ne concutiantur. Concuti enim, ut Plinii verbis utar, experimento vetant, quoniam non gignant confusis vitalibus venis.

But now at this point someone could ask how it is possible to know whether something will be hatched out from the eggs. To say the truth, I think it is very difficult to establish sure indications of this. Albertus, however, reports that eggs suited for incubation have bloody veins on the fourth day: thus at that time they can be examined at the rays of the sun, and those in which veins are visible should be placed back under the hen, the others not at all. But whoever examines the eggs should pay attention whether on the same day they appear clear in the sharper end, that is, as Pliny says, if a color devoid of impurities and uniform shows through; for such eggs are unfit for generation; likewise those in which in that moment the rooster’s semen does not appear, according to Varro. Albertus recommends they should be inspected again on the seventh day and if there is something which when held up to the sun does not seem different, the egg should be thrown away as windy and useless. But in such an examination one must pay a lot of attention to a thing, that the inspector should be very careful not to shake them. To use Pliny’s words, For they forbid them to be shaken for trial, since they do not give birth to the chick if the vital veins have been ripped apart.

Sciendum etiam tot denuo substitui posse, quot pro infoecundis reiecta fuerint. Reijciantur denique omnino hypenemia, nam quanvis partes videantur habere omnes, tamen principio carent, quod a maris semine affertur: quapropter animata non sunt, ut dilucide Aristoteles docet: qui etiam tria potissimum alias indicia adducit, quibus huiusmodi ova ex aliis distinguas. Ait[3] enim aliis minora esse, et plura numero gigni, ob unam eandemque causam. Ratio est, quia cum imperfecta sint, minus augentur, et quia minus augentur, plura numero existunt. Denique minus esse suavia, quia minus concocta. Nam concoctum in quovis genere suavius est. Ne itaque qui ova suppositurus, a venditoribus decipiatur, qui saepe subventanea pro foecundis ignarae plebeculae venditant, fugiat parva, et quorum magnam haberi copiam videt, eligat maiora, eorumque aliquo primo vescatur, ut ex dulci sapore caetera seminis participia divinet.

One must also know that as many eggs will be thrown away as infertile, as many can be substituted in turn. In conclusion, the hypenemia ones should be absolutely eliminated, for, although they seem to have all their parts, they nevertheless lack the generative principle which is provided by the semen of the male: therefore they are lifeless, as Aristotle clearly teaches: who elsewhere reports at first also three clues by which you may distinguish eggs of this kind from others. For he says they are smaller and they are produced more numerous than other eggs for only one and identical reason. Because, being imperfect, they grow less and since they grow less they are more numerous. Finally they are less palatable because they are less concocted. For in every kind of things what is concocted is more palatable. Therefore in order that who is going to put eggs under hens should not be deceived by wheeler-dealers, who often sell wind-eggs for fertile to inexperienced common people, he should shun small eggs and of which he sees there is a large abundance, he must choose the larger ones, and at first he should eat one of them, so that from its sweet taste he can foresee that the others are sharing of the semen.

Collectis modo ovis foecundis, eorum numeri etiam ratio habenda est, si veteribus credimus. Quotquot enim de agricultura scripserunt, fere omnes impari numero subijci iubent, idque hodie nescio quam vere mulierculae nostrae observant. Nam revera res non videtur superstitione carere, nisi Pythagorae forte dogmata sapere dicamus, qui summum bonum in numero impari ponebat[4]. Variant vero eiusmodi numerum cum pro uniuscuiusque Gallinae natura, tum etiam pro diversitate temporis anni. Si Gallina foecunda est, Florentinus non plura, quam viginti tria supponi iubet, pauciora vero, cum talis non est. Varro[5], et Plinius[6] negant, plus viginti quinque oportere incubare, quanvis etiam propter foecunditatem plura pepererit. Columella[7] primo tempore, id quod est mense Ianuario, non plura quam quindecim subijci vult. Martio novemdecim, nec pauciora, unum et viginti Aprili, et tota aestate usque calendas Octobris. Sed nostrae mulieres semper fere non ultra septemdecim, vel novemdecim glocientibus incubanda exhibent.

When only fertile eggs have been collected an account must also be kept of their number, if we believe the ancients. For almost all who wrote on agriculture urge that they must be placed under the hen in odd number, but at the present day I do not know how carefully our farm girls observe this rule. For in actual fact it does not seem to lack superstition, unless we affirm that perhaps it has the taste of the dogmas of Pythagoras, who placed the greatest good in an odd number. For they change such a number not only with regard to the nature of each hen, but also according to the difference of the period of the year. If the hen is fecund, Florentinus prescribes that not more than twenty-three eggs should be placed under her, but fewer eggs when she is not alike. Varro and Pliny say that  it is not worthwhile that more than twenty-five eggs are incubated, even though because of her fertility the hen laid a greater number. Columella, in the first breeding season, that is, in the month of January; wishes no more than fifteen to be placed under her. Nineteen in March, and no fewer, twenty-one in April and for the entire summer up to the kalends of October. But our women almost always give the broody-hens no more than seventeen or nineteen eggs for incubation.

Eligendum etiam tempus est incubationi maxime idoneum: siquidem totum anni tempus tale non est. Praefertur autem velut praestantissimum aequinoctium vernum, hoc est, a vigesima quarta die Martii usque ad nonas Maias[8]: nam quae post illud tempus incubantur, pullos edunt, qui plerunque, quia tardius nati, nullam aliam eo anno utilitatem hero, quam ad mensae usum, apportant. Quinim<m>o Columella[9] author est, ab aestivo solstitio bonam pullationem non haberi, quod ab eo tempore, etsi facilem educationem habeant, iustum tamen non capiant incrementum, probandam itaque aestivam educationem. Et Longolius pullos maturos dici posse putat primo vere exclusos: serotinos vero qui serius {a}eduntur, quos patria lingua autumnales vocari asserit, eos ait sub veris initio necdum parere, quemadmodum quos maturos vocat; quamobrem, inquit{;}<,> non ad pullationem, sed ad veru aluntur. Alibi[10] etiam Columella post Octobrem supervacuam incubationis curam esse scribit, quoniam frigoribus exclusi pulli plerunque intereant. Plinius[11] tamen ad Calendas Novembris usque tempus extendit, et terna dena etiam supponi iubet, sed ab eo die vetat donec bruma conficiatur: admittit denique hyemalem incubationem, sed pauciora tunc incubari cupit, non tamen infra novena. Incubent itaque Gallinae quoties glociunt, et Gallinarii sit exclusos frigore pullos loco calidiori enutrire.

The more suitable time for incubation must also be chosen: since the whole space of the year is not alike. As very excellent the vernal equinox is preferred, that is, from the twenty-fourth day of March to the nones of May - May 7th: for those incubated after that time bring forth chicks which, because they are born later, mostly provide the master in that year no other advantage than table use. But actually Columella says that from summer solstice there is no good production of chicks, because from that time, although they are easy raised, they do not, however, get a proper growth, and thus the summer raising must be regarded as right. Also Longolius thinks that they can be called mature chicks if hatched in the early spring: but those belated which are born later, which he asserts are called autumnal in his native tongue, he says that they not yet lay at the beginning of spring, as on the contrary are doing those he calls mature; therefore, he says, they are not raised for reproductive purposes, but for spit. Elsewhere Columella also writes that it is useless to devote ourselves to eggs incubation after October, since chicks hatched out in the cold weather generally perish. Pliny, however, extends the period to the kalends of November, and urges that even thirteen eggs at once are placed under the hen, but from that day onward he forbids until the winter ended up: lastly he allows winter incubation, but he want that in this time fewer eggs are incubated, nevertheless not less than nine at once. Therefore the hens should incubate whenever they cluck, and it should be care of the chicken raiser to rear in a warmer place the chicks hatched out in the cold.

Porro et Lunae ratio habenda est in suppositione. Nam in defectu illius prohibetur; et dum nova est, ut Plinius monet, vel saltem dum crescit, hoc est, a novilunio usque ad decimam quartam diem, laudatur. Ova enim ante novilunium subiecta, Varro[12], et Plinius[13] non succedere inquiunt, hoc est non producere pullos, Florentinus tabescere, et corrumpi, eo quod a plenilunio usque ad novilunium evanescant, ut in conchiliis etiam observamus, et e contrario omnia a novilunio usque ad plenilunium repleantur, et humectentur. Columella[14] semper quidem considerari vult, ut luna crescente supponantur, verum nisi a decima, postquam creverit, die usque ad quintadecimam: idque Palladius[15] comprobat, et Tragus a mulierculis in Germania etiamnum observari scribit. Ex huiusmodi autem suppositione eam utilitatem dimanare inquit, quod pulli in [224] crescente iterum luna excludantur: et revera hic incubandi modus satis laudari nequit, dignus ut ab omnibus instituatur.

Furthermore, for incubation, account must be taken also of the moon. For it is forbidden during its absence, and when it is new, as Pliny advises, or at least when it is growing, that is, from the new moon up to the fourteenth day, incubation is praised. In fact the eggs placed under the hen before the new moon Varro and Pliny say that they are unsuccessful, that is, they do not produce chicks, Florentinus says they  melt and go bad, because from the full moon to the new moon they evaporate, as we also observe in shellfish, and on the contrary all of them grow full and moist from the new moon to the full moon. For Columella wishes care always to be taken that eggs should be set under the hen while the moon is growing, and to say the truth only from the tenth day after the moon began to grow up until the fifteenth: also Palladius confirms this and Tragus - Hieronymus Bock - writes that this practice is even now observed by farm girls in Germany. For he says that from such a method of placing eggs comes an advantage, because the chicks are hatched when the moon is growing again: and in fact this method of incubation cannot be sufficiently praised, and is worthy of being introduced by everybody.