Page:The Works of William Harvey (part 1 of 2).djvu/371

 ON GENERATION. 2/1

the male and the female, equally endued with the virtue of either, and constituting an unity from which a single animal is engendered.

Nor is it the beginning only, but the fruit and conclusion like- wise. It is the beginning as regards the being to be engendered; the fruit in respect of the two parents : at once the end proposed in their engendering, and the origin of the chick that is to be. "But the seed and the fruit," according to Aristotle, 1 "differ from one another in the relations of prior and posterior; for the fruit is that which comes of another, the seed is that from which this other comes : were it otherwise, both would be the same."

The egg also seems to be a certain mean; not merely in so far as it is beginning and end, but as it is the common work of the two sexes and is compounded by both; containing within itself the matter and the plastic power, it has the virtue of both, by which it produces a foetus that resembles the one as well as the other. It is farther a mean between the animate and the in- animate world; for neither is it wholly endowed with life, nor is it entirely without vitality. It is still farther the mid-passage or transition stage between parents and offspring, between those who are, or were, and those who are about to be; it is the hinge and pivot upon which the whole generation of the bird revolves. The egg is the terminus from which all fowls, male and female, have sprung, and to which all their lives tend, it is the result which nature has proposed to herself in their being. And thus it comes that individuals in procreating their like for the sake of their species, endure for ever. The egg, I say, is a period or portion of this eternity; for it were hard to say whether an egg exists for the sake of the chick that it engenders, or the pullet exists for the sake of the egg which it is to engender. Which of these was the prior, whether with reference to time or nature, the egg or the pullet? This question, when we come to speak of the generation of animals in general, we shall discuss at length.

The egg, moreover, and this is especially to be noted, corresponds in its proportions with the seeds of plants, and has all the same conditions as these, so that it is to be regarded, not without reason, as the seed or sperma of the common fowl,

1 De Gen. Anim. lib. i, cap. 13.