Excerpted from De generatione et corruptione

It has already been proved in the previous sections that the elements from which corruptible things are generated are four and no more. And, when the one who considers this thinks about it, he will find that plants and animals, which are generated in earth, are nourished from earth and air and water, and their actuality is completed by heat arranging them. For earth makes the generated thing acquire [the power to] retain ... what is acquired when it is made and shaped. And water makes it easy for the generated thing to receive a shape. And the substance of water is preserved, since it is fluid, on account of being mixed with earth; and the substance of earth is preserved from diminution on account of being mixed with water. And air and fire keep [earth and water] from acting as elements and make them acquire the balance of a composite; and air opens up [the composite and makes for pores and pathways [for activities such as sensation and respiration], and fire digests, fuses, and aggregates.

original latin

Et quodlibet istorum elementorum habet latitudinem in sua qualitate secundum magis et minus, quia sua qualitas naturalis vel accidentalis poterit intendi et remitti, observando adhuc formam et speciem suam. Nihilominus, ista intensio et remissio habent terminos limitatos quos, quando transcendit, deperditur completa dispositio quae est in materia ad illam formam et disponitur dispositione completa ad aliam formam.

Et de usu materiae est, quando disponitur dispositione completa ad recipiendum formam, quod scilicet influatur illa forma super eam a datore formarum in materiebus, [et recipit eam] et amovet alias. Et idcirco appropriantur materiae consimiles ut sint materiae diversarum formarum a datore formarum.
Et debes scire quod potentia est unum, et dispositio completa est aliud; et in materia sunt omnes contrarietates in potentia, sed appropriatur in una diversitatum quae est inter alias res diversas, per illud quod renovatur in ea [de] dispositione completa quae appropriat eam materiam cum ea forma in aliqua re.

Et diversificantur complexiones istorum compositorum propter diversitatem qualitatum elementorum in ipsis. Generatorum aliud est in quo vincit terra vel terreitas et est totum illud quod cadit et ponderat et descendit in aere et aqua, tam ex animalibus quam ex plantis quam ex mineralibus.
quam ex mineralibus ...
Et sunt in mixionte aliqua in quibus vincit aqueitas, et aliqua in quibus aeritas.

Et est in quo vincit igneitas, et istud est totum illud quod elevatur in aere, et erit possibile quod sit ibi qui non ascendat sed, dato quod vincat igneitas, erit istud oppositum illius de quo diximus in quo vincit terrestreitas.