In the following items, each passage consists of six sentences. The first sentence (S1) and the final sentence (S6) are given. The middle four sentences in each have been removed and jumbled up. These are labelled P, Q, R and S. You are required to find out the proper sequence of the four sentences and mark accordingly on the Answer Sheet. 

S1: In 1668 an important discovery was made. 
P: He put some rotting meat and fish in open jars and watched them. 
Q: When he covered the jars with muslin, he found that flies carne and laid their eggs on the muslin; but no maggots developed on the meat. 
R: In time, he noticed that flies carne and laid their eggs in the meat and the maggots hatched from the eggs
S: An Italian physician named Redi decided to test the idea that worms were generated spontaneously in rotting meat. 
S6: That was the beginning of the end of the theory of spontaneous generation of higher plants and animals.