William Harvey, The Works of William Harvey M.D
“ Some will have it that the semen or the blood is the matter whence the chick is engendered; others, that the semen is the agent or efficient cause of its formation. Yet to him who dispassionately views the question is it quite certain that there is no prepared matter present, nor any menstruous blood to be coagulated at the time of intercourse by the semen masculinum, as Aristotle will have it; neither does the chick originate in the egg from the seed of the male, nor from that of the female, nor from the two commingled. ”
