Foundations of Experimental Biology
William Harvey and the Circulation of the Blood
Figures 1 and 2 from William Harvey,
Exercitatio Anatomica de Motu Cordus et Sanguinis in Animalibus,
1628, demonstrating the valves in the veins.
(Readings: Harvey, chapters VIII - XVII, plus Harvey's letter to Hofmann
and two essays to Riolan, in Harvey, Movement of the Heart and Blood.)