Francesco Redi’s 1668 meat-jar experiment showed that maggots emerged from meat left exposed to flies.
Redi placed meat in several containers: some were open, some were sealed, and others were covered with gauze. Maggots appeared on the exposed meat and on the gauze where flies could reach it, but not on meat protected from flies.
The experiment challenged the widespread belief in spontaneous generation, the idea that living organisms could arise directly from nonliving material. Redi’s results supported the conclusion that maggots came from fly eggs.
The experiment did not settle every later debate about spontaneous generation. In particular, arguments continued about microorganisms until experiments by Louis Pasteur. Redi’s work remains an early landmark in controlled biological experimentation.