Embryology

At the time, it was customary to think that seeds, eggs, pollen, sperm, etc, had miniature organisms in them that grew. Some thought that this was recursive! Wolff found that specialized organs developed out of unspecialized tissue.
 Kaspar Friedrich Wolff Germany 1759 Embryology

At the time, it was customary to think that seeds, eggs, pollen, sperm, etc, had miniature organisms in them that grew. Some thought that this was recursive! Wolff found that specialized organs developed out of unspecialized tissue.