Hieronymus Fabricius is the Latin name by which the ItaliananatomistGirolamo Fabrici (May 20, 1537 – May 21, 1619) is better known. Also known as Fabrizo d'Acquapendente and (Italian) Geronimo Fabrizio.
By dissecting animals, Fabricius investigated the formation of the foetus, the structure of the oesophagus, stomach and bowels, and the peculiarities of the eye, the ear and the larynx. His main claim to fame is the discovery of the membranous folds, which he names "valves" in the interior of veins that, at the time he did not know but what was later discovered, prevent blood from flowing backwards on its way to the heart.
Fabricius's pioneering work earned him the title of 'The Father of Embryology' in Italian medical science.