Among the many scientists who studied the cutaneous blood supply, Gino Pieri, an Italian Army surgeon operating during World War I, deserves attention. During those times, amputations were frequent, and flaps used to cover stumps were often inadequately designed and became necrotic, because of poor knowledge of the skin's blood supply. Pieri solved the problem after drawing a perforator map of human body skin, injecting the main arteries with methylene blue dye. His flaps were mainly designed along the course of what Ian Taylor would call "source" arteries, to capture the greatest perforators.