Malpighi's De polypo cordis: an annotated translation.

Malpighi's De polypo cordis (1666) represents a significant contribution to the understanding of blood, its composition and its clotting. In this work, written during his occupation of the primary Chair of Medicine at Messina (1662-66),l he recognized, albeit dimly, fibrinogen as a regular component of blood, and began to investigate the conditions which provoke or prevent clotting, either intravascularly or in shed blood. His microscopes had enabled him to discover the pulmonary capillaries five years earlier. Now he provided the first precise description, aided by microscopy, of the laminar structure of a clot and the sequence of its formation. He specified how the appearance of post-mortem clot in the left and right sides of the heart differed. Here too it can be claimed that the first sighting of red blood cells is recorded, although Malpighi was at the time far from appreciating their significance.