Matthew Cobb, guest-blogging at Why Evolution Is True, gives an appreciation of Nicholas Steno's contributions to biology: "Google’s doodle: women have eggs".
‘The testicles of women are analogous to the ovary’: in other words, women have eggs. This amazing statement – almost a throwaway comment in a brief section on sharks – was the start of our modern understanding of both human reproduction, and on the essential unity of the animal kingdom.
Cobb is the author of Generation: The Seventeenth-Century Scientists Who Unraveled the Secrets of Sex, Life, and Growth, which goes through this interesting chapter in the history of science, with names like Steno, Swammerdam, Leeuwenhoek all interconnected with each other.