Each of the following question consists of six sentences of a passage. The first and sixth sentences are given as S1 and S6. The middle four sentences in each have been jumbled up and labelled as P, Q, R and S. Find the proper sequence of the four sentences and mar your response accordingly.

S1: The color of animals is by no means a matter of chance; it depends on many considerations. 

P: There are, however, not a few cases in which vivid colors are themselves protective. 

Q: But in the majority of cases it tends to protect the animal from danger by rendering it less conspicuous.

R: The kingfisher itself, though so brightly colored, is by no means easy to see.

S: Perhaps it may be said that if coloring is mainly protective, there ought to be but few brightly colored animals. 

S6: The blue harmonizes with the water, and the bird as it darts along the stream looks almost like a flash of sunlight.