Page:The Works of William Harvey (part 1 of 2).djvu/500

 formerly consisted, and this, taking place according to all their dimensions, they are distinguished as regards their parts, and are organized at the same time that they grow.

But to engender the chick is in truth nothing else than to fashion or make its several members and organs, which, although they are produced in a certain order, and some are postgenatc to others, the less important to the more principal organs still, whilst the organs themselves are all distinguished, they are not engendered in such wise and order that the similar parts are first formed, and the organic parts afterwards compounded from them ; or so that certain composing parts existed before other compounded parts which must be fashioned from them. For although the head of the chick and the rest of the body exist in the shape of a mucus or soft jelly, whence each of the parts is afterwards formed in sequence, and all are of similar con- stitution in the first instance, still are they simultaneously pro- duced and augmented in virtue of the same processes directed by the same agent ; and in the same proportion as the matter resembling jelly increases, in like measure are the parts distin- guished; for they are engendered, transmuted, and formed simultaneously; similar and dissimilar parts exist together, and from a small similar organ a larger one is produced. The thing, in short, is not otherwise than it is among vegetables, where from the straw proceeds the ear, the awns, and the grain dis- tinctly, severally, and yet together ; or as trees put forth buds, from which^are produced leaves, flowers, fruit, and finally seed.

All this we learn from an attentive study of the parts and processes of the incubated egg, inasmuch, as from things done, actions or operations are apprehended; from operations, facul- ties or forces, and from these we then infer the artificer, gene- rator, or cause. In the generation of the pullet, consequently, the actions or faculties of the engendering cause enumerated by Fabricius, namely, the metamorphic and formative, do not differ in kind, or even in the relation of sequence, as that one is first and the other second, but, as Aristotle is wont to say, are one and the same in reason ; not as happens with reference to the actions of the nutritive faculty, attraction, concoction, dis- tribution and apposition, to wit, which all come into play in several places at several times. Were this not so, the engen-