Of deeper interest, as marking Aristotle's prevision, is his anticipation of what is known as Epigenesis, or the theory of the development of the germ into the adult form among the higher individuals through the union of the fertilizing powers of the male and female organs. This theory, which was proved by the researches of Harvey, the discoverer of the circulation of the blood, and is accepted by all biologists to-day, was opposed by Malpighi, an Italian physician, born in 1628, the year in which Harvey published his great discovery, and by other prominent men of science down to the last century. Malpighi and his school contended that the perfect animal is already "preformed" in the germ; for example, the hen's egg, before fecundation, containing an excessively minute, but complete, chick. It therefore followed that in any germ the germs of all subsequent offspring must be contained, and in the application of this "box-within-box" theory its defenders even computed the number of human germs concentrated in the ovary of mother Eve, estimating these at two hundred thousand millions! When the "preformation" theory was revived by Bonnet and others in the eighteenth century, Erasmus Darwin, grandfather of Charles Darwin, passed the following shrewd criticism on it: "Many ingenious philosophers have found so great difficulty in conceiving the manner of reproduction in animals that they have supposed all the numerous progeny to have existed in miniature in the animal originally created. This idea, besides its being unsupported by any analogy we are acquainted with, ascribes a greater continuity to organized matter than we can readily admit. These embryons ... must possess a greater degree of minuteness than that which was ascribed to the devils who tempted St. Anthony, of whom twenty thousand were said to have been able to dance a saraband on the point of a needle without the least incommoding each other."