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Period: 753 BCE to
Spontaneous generation widely accepted
Since acient Rome to the late 19th century, the concept of spontaneous generation is widely accepted -
Francesco Redi's experiment
Francesco Redi conducts an experiment using three types of jars with meat to disprove spontaneous generation of maggots. The experiment shows that the presence of flies is necessary for the generation of maggots. -
John Needham's experiment
John Needham claims that spontaneous generation can occur and performs an experiment by boiling broth and sealing the flasks. After observing living microorganisms in the sealed broth, he concludes that spontaneous generation is a fact. -
Period: to
Lazzaro Spallanzani's experiments
Lazzaro Spallanzani disagrees with Needham's conclusions and performs a series of experiments that show that microorganisms do not spontaneously arise from boiled broth but instead come from contaminated air. -
Louis Pasteur's swan-neck flask experiment
Louis Pasteur designs the swan-neck flask experiment, where he shows that life forms in broth only appear when the flask is exposed to air that contains trapped particles, not from a supposed "life force." -
Pasteur's final remark
Pasteur articulates "Omne vivum ex vivo" ("Life only comes from life") in a lecture and declares that spontaneous generation will never recover from the blow of his experiment.