Andrea Cesalpino (Latinized as Andreas Cæsalpinus) (6 June 1524 – 23 February 1603) was a Florentine physician, philosopher and botanist. In his works he classified plants according to their fruits and seeds, rather than alphabetically or by medicinal properties. In 1555, he succeeded Luca Ghini as director of the botanical garden in Pisa. The botanist Pietro Castelli was one of his students. Cesalpino also did limited work in the field of physiology. He theorized a circulation of the blood. However, he envisioned a "chemical circulation" consisting of repeated evaporation and condensation of blood, rather than the concept of "physical circulation" popularized by the writings of William Harvey (1578–1657). Biography Cesalpino was born in Arezzo, Tuscany. For his studies at the University of Pisa his instructor in medicine was R. Colombo (d. 1559), and in botany the celebrated Luca Ghini. After completing his course he taught philosophy, medicine, and botany for many years at the same university, besides making botanical explorations in various parts of Italy. At this time the first botanical gardens in Europe were laid out; the earliest at Padua, in 1546; the next at Pisa in 1547 by Ghini, who was its first director. Ghini was succeeded by Cesalpino, who had charge of the Pisan garden 1554–1558. When far advanced in years Cesalpino accepted a call to Rome as professor of medicine at University of Rome La Sapienza and physician to Pope Clement VIII. It is not positively certain whether he also became the chief superintendent of the Roman botanical garden which had been laid out about 1566 by one of his most celebrated pupils, Michele Mercati. Philosophical works All of Cesalpino's writings show the man of genius and the profound thinker. His style, it is true, is often heavy, yet in spite of the scholastic form in which his works are cast, passages of great beauty often occur. Modern botanists and physiologists who are not acquainted with the writings of Aristotle find Cesalpino's books obscure; their failure to comprehend them has frequently misled them in their judgment of his achievement. No comprehensive summing up of the results of Cesalpino's investigations, founded on a critical study of all his works has appeared, neither has there been a complete edition of his writings. Seven of these are positively known, and most of the seven have been printed several times, although none have appeared since the 17th century. In the