Francesco Redi`s Experiment. Spontaneous Generation Stock Photo

To test the hypothesis, Francesco Redi placed fresh meat in open containers: as expected, the rotting meat accracted flies, and the meat was soon swarming with maggots, which hatched into flies. When the jars were covered so that flies could not get in, no maggots were produced. To answer the objection that the cover cut off fresh air necessary for spontaneous generation, Redi covered the jars with porous gauze instead of an air-tight cover. Flies were attracted to the smell of the rotting meat, clustered on the gauze, which was soon swarming with maggots, but the meat itself remained free of maggots. Thus flies are necessary to produse flies: they do not arise spontaneously from rotting meat