Marcello Malpighi (10 March 1628 – 29 November 1694) was an Italian biologist and physician, who is referred to as the "Father of microscopical anatomy, histology, physiology and embryology". Malpighi's name bears to several physiological features related to the biological excretory system, such as the Malpighian corpuscles and Malpighian pyramids of the kidneys and the Malpighian tubule system of insects. The splenic lymphoid nodules are often called the "Malpighian bodies of the spleen" or Malpighian corpuscles. The botanical family Malpighiaceae is also named after him. He was the first person to see capillaries in animals, and he discovered the link between arteries and veins that had eluded William Harvey and Malpighi has been the earliest person to observe red blood cells under a microscope. His treatise De polypo cordis (1666) was important for understanding blood composition, as well as how blood clots. In it, Malpighi described how the form of a blood clot differed in the right against the left sides of the heart.