They have studied much more closely the ever varying qualities of light, as it differs according to place and season and even time of day. Monet has painted a series of pictures the subject of every one of which is the same haystack. At least that is how some people might describe them. But, if they enter into Monet’s point of view, they would say that the real subject is not the haystack but the effect of light upon its surface, and, as the effect of light is different in every case, none of the pictures are similar to one another. Each represents a separate fugitive expression of light. Monet, in them and other pictures, has recorded with extraordinary subtlety the impression presented to his eye. For Monet’s _impressionism_ was also _naturalistic_.