Page:The Works of William Harvey (part 1 of 2).djvu/447

 lific or wind eggs consist herein, that the former contained the seed of the male, as Aldrovandus supposed; nor has it been noticed that anything has been formed and coagulated in the egg by the seed of the male, nor has any sensible transmuta- tion been discovered (for indeed, there is no sensible difference between the fertile and the wind egg) ; and yet a prolific egg, conceived long after coition, has in itself the faculties of both sexes ; viz., the capability of being both formed itself, and of forming a chick ; as if, according to the idea of Aristotle, it had derived its origin from the coition of the two, and their mutual endeavours towards the same end ; and compelled by the force of this argument, as mentioned above, when speaking of the generation of the ovum, he has endowed the egg with a vital principle (anima.) If such really exist, then, without doubt it would be the origin and efficient of all the natural phenomena which take place in the egg. For if we consider the struc- ture of the chick, displaying, as it does, so much art, so divine an intelligence and foresight ; when we see the eyes adapted for vision, the bill for taking food, the feet for walking, the wings for flying, and similarly the rest of its parts, each to its own end, we must conclude, whatever the power be which creates such an animal out of an egg, that it is either the soul, or part of the soul, or something having a soul, or some- thing existing previous to, and more excellent than the soul, operating with intelligence and foresight.

From the generation of the chick, it is also manifest that, whatever may have been its principle of life or first vegetative cause, this cause itself first existed in the heart. Now, if this be the soul of the chicken, it is equally clear, that that soul must have existed in the punctum saliens and the blood ; since we there discover motion and sense ; for the heart moves and leaps like an animal. But if a soul exists in the punctum saliens, forming, nourishing, and augmenting the rest of the body, in the manner which we have pointed out in our history, then it, without doubt, flows from the heart, as from a foun- tain-head, into the whole body. Likewise, if the existence of the vital principle (anima) in the egg, or, as Aristotle supposes, if the vegetative part of the soul be the cause of its fertility, it must follow that the punctum saliens, or ani- mate genital part, proceeds from the vital principle (anima) of