Three kinds of animals did not enter the ark. One is the kind of fishes and of all that live in the waters: for to these the flood brought no harm. To these may also be reckoned those which are of ambiguous life and are called amphibians; for although these often dwell out of the waters on land, yet they seek the land not from necessity, but for the sake of catching pleasure or prey, or of hiding their offspring. But if even these cannot make a long stay in the waters, that does not at all disturb our reasoning, for it has been shown above that there was sufficient room in the ark for taking these too. The second is the kind of those generated from the mingling of animals of a different species, such as the mule (male and female) from the horse and the ass: for it was enough that the parents of these were preserved in the ark — namely, those from whose union their kind could again be restored after the flood was over. The third kind is of those created from putrefying matter: for since at no time after the flood would there be lacking putrefying matter, nor the celestial force from which the generation of such animals arises, their preservation in the ark was not necessary.¹

Tostatus, on the second chapter of Genesis, question 2, makes six species of this kind of animal, writing in this manner: “Of imperfect animals, which are generated from putrefactions, there are commonly six kinds. Some are generated from exhalations, such as gnats (bibiones) — the tiniest animals, begotten from the exhalations of wine — and butterflies from water; some from the corruptions of humors, such as worms in dung or in cisterns. Some from carcasses, such as bees from beasts of burden, hornets (that is, large flies that buzz in flying), and beetles and green flies from dead horses or dogs, and the Scorpion from the flesh of a dead Crab. As Ovid says, Metamorphoses 15: ‘If you take away the hollow claws of the shore-Crab, and lay the rest beneath the earth, from the buried part a Scorpion will come forth and threaten with its hooked tail.’ A serpent is also born from the marrow of the human spine, as Isidore says in the 15th book of the Etymologies — concerning which Ovid, in Metamorphoses 15:”²

“There are those who believe that, when the spine has rotted in the closed sepulchre, human marrow is changed into a serpent.” Some [are generated] from the rot of wood, such as wood-worms (teredines), which are worms born within timbers when they are not cut at the due time. Some from the corruption of herbs, such as the moth; some from the corruption of fruits, such as weevils (gurguliones) from beans. Of these six species of animals it is said that they were not immediately created by God, but were afterward naturally formed from corruption — yet God implanted the seminal causes of these in things. This [says] Tostatus.³

That the three aforesaid kinds of animals were excluded from the ark, the very narrative of Moses indicates not obscurely. And concerning the aquatic ones no one could have any doubt, since God commanded only land and flying creatures to be brought into the ark, no mention being made of fishes or aquatic creatures. Concerning the other two kinds the same is manifest from this: that in every kind of animal which God commanded to be received into the ark, he willed there to be a distinction of both sexes — that is, of male and female — without doubt to this end, that again, by such mingling of the sexes, generating things like themselves, they might preserve and propagate their species. Therefore whatever either does not have a distinction of sex, or is not generated from the mingling of both sexes, or does not itself, through the mingling of male and female, generate anything else — these, one must confess, were not in the ark. The mule (male and female) is indeed generated from the mingling of male and female, and has in itself the distinction of both sexes; but they nevertheless generate nothing through such mingling, and therefore their species is preserved and perpetuated not on account of their active generation, but only on account of the passive [generation] from the horse and the ass.⁴

Our opinion concerning the animals that did not enter the ark is confirmed by the authority of St. Augustine — most similar to the things we have here taught — in the fifteenth book of The City of God, chapter twenty-seven, writing in this manner: “But as for that which is wont to be asked most scrupulously about the tiniest little creatures — not only such as mice and lizards, but even such as locusts, beetles, flies, and finally fleas — whether they were not in that ark in greater number than is [there] defined, when God commanded this: those whom these things trouble must first be advised that what was said, ‘Which creep upon the earth,’ is to be understood thus, that it was not necessary to preserve in the ark those which can live in the waters — not only submerged, like fishes, but also floating on the surface, like many winged creatures. Next, when it is said, ‘There shall be male and female,’ it is without doubt understood to be said for the restoring of the kind; and through this, neither was it necessary that those be there which can be born without copulation, from various things or from the corruptions of things; or, if they were there — as they are wont to be in houses — they could have been defined by no number: or, if the most sacred mystery being enacted, and so great a figure of the thing, could not be fulfilled even in the truth of the fact otherwise than that all things should be there in that fixed number which could not, nature forbidding, live in the waters — this was not the care of that man or of those men, but divine. For Noah did not bring them in captured, but admitted them as they came and entered. For to this end…”⁵

“…to this end is what was said, ‘They shall enter to thee’ — not, that is, by the act of man, but by the nod of God: in such a way, indeed, that those which lack sex are not to be believed to have been there. For it was prescribed and defined, ‘There shall be male and female.’ For there are some which are born from various things without copulation, in such a way that afterward they copulate and generate, like flies; but others in which there is nothing of male or female, like bees. But those which have sex in such a way that they have no offspring, like mules, it would be strange if they were there, and not rather that their parents — namely, the horse-kind and the ass-kind — being there should have sufficed; and if there are any others which, from the mingling of a different kind, lead forth some [other] kind, yet if this pertained to the mystery, they were there: for this kind too has male and female.” So Augustine.⁶