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Giulio Cesare Aranzi

Born  1529
Died  1589-04-07

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Italian anatomist and surgeon, born 1529/1530, Bologna; died April 7, 1589, Bologna.

Biography of Giulio Cesare Aranzi

Giulio Cesare Aranzi
His name is also commonly given as Julius Caesar Arantius, his family name as Aranzio.

Aranzi was one of the prominent anatomists who raised Italy to a leading position in 16th century science. He was born in Bologna in 1529 or 1530, the son of Ottaviano di Jacopo and Maria Maggi. Because of his parent's poverty he commenced his studies at 18, under his uncle, the famous surgeon Bartolomeo Maggi (1477-1552), lecturer in surgery at the University of Bologna and principal court physician of Julius III. He was a favourite pupil of his uncle, whom he loved and esteemed so highly that he assumed his surname, calling himself Giulio Cesare Aranzio Maggio.

Aranzio entered the University of Padua, where in 1548, at nineteen, he made his first anatomical discovery: the elevator muscle of the upper eyelid. He was conferred doctor of medicine in Bologna on May 20, 1556, and shortly thereafter, at the age of twenty-seven, he became lecturer in medicine and surgery at the same university.

Aranzio was the first lecturer at the University of Bologna to hold a separate professorship of anatomy. Prior to him, instruction was given by lectures in surgery. He himself began as a lecturer in surgery, but in 1870 he was able to have the two subjects separated, so that each would have its own professorship. Aranzio held both tenures until his death on April 7, 1589, 33 years later, beloved and esteemed by his students.

One of his most important works is a small book entitled De humano foetu liber (Rome, 1564). In it he proves, that with dilatation of the uterus the thickness diameter of the *Wandungen* will increase, and that the urachus is not perforated in man. Fifteen years later he published his Observationes anatomicae. In these books he presented the new direction of anatomy, based not merely on simple description of the organs of the body but also on experimental investigations of their functions. His work is characterised by his clear diction as well as the modesty with which he presents himself as a writer, always recognising the achievements of others.

Aranzi shared his interest in pelvic constriction with his pupil Geronimo Mercurio (or Mercuriale). To study its variations, both of them dissected the dead bodies of pregnant women.

Aranzi was a meticulous and unprejudiced observer to whom anatomy owes several discoveries. The excellent scientific and practical preparation he had received from his uncle immediately brought him fame. Besides the musculus levator palpebrae superioris, which he had discovered in his first year of study, he discovered the pedes hippocamp, the cerebellum cistern, first described the ammon horns, and the fourth ventricle, the arterial duct - ductus arteriosus - which discovery was erroneously attributed to Leonardo Botallo (1530-1600), as well as the ductus venosus (Arantii). Contrary to Vesalius he maintained the impermeability of the dividing walls of the heart. He also discovered that the blood of mother and foetus is kept separate during pregnancy. In 1564 he coined the term "hippocampus".

We thank Gonzalo Moscoso for correcting an error in our original entry.


  • De humano foetu opusculum.
    Rome, 1564; Venice, 1571; Basel, 1579.
    32: De formato foetu. Bononiae, J. Rubrius, 1564.
  • De tumoribus secundum locus affectum. Bologna, 1571.
  • In Hippocrates librum de vulneribus capitis. Leiden, 1580.
  • Observationes anatomicae. Basel, 1579; Venice 1587. Thse works were published together in Venice in 1587:
  • De tumoribus prater naturam secundum locos affectus liber.
  • De humano foetu liber.
  • Anatomicarum observationum liber.

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