Fuentes de Juan de Arfe para el Libro tercero de la Varia commensuración

This article examines the Third Book of the Varia commensuración by Juan de Arfe (1587), dedicated to describe measures of quadruped animals and birds. We have located the erudite sources of his statements in Pliny, Aristotle, Saint Isidore and Bartholomeus Anglicus, and, based on information from authors contemporary to Arfe, we propose locations where he could see the animals he mentions, some of them quite exotic, with his own eyes. Taking into account the engravings, we suggested possible iconographic sources and discovered details related to the logic of what was expressed in the text by the treatiser.