Malpighi, MarcelloPronunciation: /malˈpiːgi/Definition of Malpighi, Marcello (circa 1628–94), Italian microscopist. He discovered the alveoli and capillaries in the lungs and the fibres and red cells of clotted blood, and demonstrated the pathway of blood from arteries to veins. Derivatives MalpighianPronunciation: /maLˈpɪgɪən/ adjective Malpighi, Marcello in other Oxford dictionaries Definition of Malpighi, Marcello in the US English dictionary