447 years ago today, April 1, 1578 (February 25, 1578 in the lunar calendar), was the birthday of British physiologist Harvey. William Harvey, the founder of modern physiological science, passed away. Harvey was born on April 1, 1578, and came from a wealthy family. At the age of 16, he went to Cambridge to study medicine and received a postdoctoral medical doctor. He practiced medicine and conducted research in London. After 1618, he served as the personal physician of the King of England. In 1628, he published the book "A Study on Animal Heart and Blood Exercise", clarifying the theory of blood circulation. In 1651, he published "On Animal Reproduction". His reputation was growing day by day, but he was also attacked by some schools of thought. He died on June 3, 1657.