How did mice appear according to the theory of spontaneous generation? - briefly
Proponents of spontaneous generation asserted that mice emerged directly from decaying organic matter such as grain or mud. They maintained that no parental organisms were necessary for the appearance of these rodents.
How did mice appear according to the theory of spontaneous generation? - in detail
The hypothesis of spontaneous generation asserted that living organisms could arise directly from inorganic or decaying material without parental lineage. Proponents applied this idea to rodents, claiming that mice emerged from stored grain, hay, or other organic waste.
Early accounts described mice appearing in granaries after weeks of moisture accumulation. Observers noted that fresh wheat, when left exposed to damp conditions, seemed to produce small, brown mammals within a short period. The phenomenon was interpreted as evidence that the combination of grain, moisture, and heat supplied the necessary “vital force” for mouse formation.
Experimental attempts sought to reproduce the process under controlled conditions. One method involved placing uncooked wheat in a sealed vessel, adding a small amount of water, and leaving the container in a warm environment. After several days, observers reported the presence of mouse-sized rodents. The procedure was repeated with barley and rye, producing similar results according to contemporary reports.
Criticism emerged from controlled experiments that eliminated potential contamination. A notable study introduced a fine mesh barrier between the substrate and the external environment, preventing insects or eggs from entering. When the barrier remained intact, no mice appeared, whereas removal of the barrier allowed rodents to materialize. This outcome suggested that external agents, rather than the substrate itself, were responsible for the observed births.
Later investigations employed sterilization techniques, such as boiling the grain and sealing the container. Under these conditions, the appearance of mice ceased entirely, indicating that heat‑resistant spores or eggs were the true source. The disappearance of the phenomenon after sterilization contributed to the abandonment of the spontaneous generation model for rodents.
The cumulative evidence demonstrated that mice did not originate from grain or other non‑living matter. Instead, they resulted from eggs or embryos introduced by insects, contaminated tools, or environmental exposure. The theory was ultimately supplanted by germ theory and the understanding that all higher organisms arise from pre‑existing life forms.