What is the accepted theory of redi's origin of flies

Scientist's once believed that living organisms could be created from non-living matter. It was known as Spontaneous Generation. In 1668, an Italian scientist, Francesco Redi, postulated that the theory of Spontaneous Generation is incorrect. He designed a scientific experiment to test the spontaneous creation of maggots. He put fresh meat in each of the two different jars. One jar was left open and the other jar was covered with a cloth. Several days later the open jar contained maggots; the covered jar contained no maggots in the jar - they were found on the cloth covering the jar. He thus successfully demonstrated that maggots came from fly eggs. He also thought he helped disprove the theory of Spontaneous Generation. Unfortunately, he did not.