The theory of spontaneous generation was..

The theory of spontaneous generation was proposed by Aristotle. After Aristotle, many other scientists came in support of this theory.

The theory of spontaneous generation simply explains that the living matter originated from non-living matter. As soon as the theory was brought forward, contradictions arose in the scientific world with some scientists supporting the theory and the others denying it.

Some of the supporters of the spontaneous generation gave an example of how animals such as frogs can only be seen in the muddy areas. They thought that the non- living mud might have gave existence to the frogs.

However, in the future, with more scientific advancements, this theory was proved to be wrong.

answer: ice crystals in air

the water from the water body or another source of water gets evaporated as water vapor as an effect of heat on water. these water vapor rises in the upper layers of the earth atmosphere under high atmospheric pressure. the atmospheric pressure of these water molecules starts to decrease due to the effect of cold air. the invisible water vapor condenses into visible water droplets and ice crystals.these ice crystals and water droplets being less denser than the surrounding air floats on air as clouds.