We have spoken of the human eye being sensitive to an immense variety of colors. Let us consider the meaning of sensitive. In the first place, the eye receives an impression that causes it to telegraph to the brain a record of the hue; but it means more, for the word sensitive implies a capacity to feel. In some way or other the brain receives an impression of feeling. Just how it does, I understand, is not known; but scientists tell us that these impressions of sight, while they are not quite similar to the feelings aroused by sound, have something in common. Just as some sounds give pleasure while others are disturbing, so with colors--we receive from them sensations of pain or pleasure. According to the degree of our sensitiveness to sound or color our feelings are aroused. It may be only slightly, or it may be more intensely. It is pleasant, for example, to hear the sound of the robin’s note, and, as we peep out of our bedroom window to look at him, we may catch sight of the yellow or red notes of color that the tulips are beginning to make against the dark earth. They too will give us pleasure. And in both cases our pleasure may go no further than just a little enjoyment of their note of color or sound. Or, on the other hand, they may stir our imagination. We recognise their notes as the first signs of spring. Nature in her mysterious way has whispered alike to the robin and the tulip that the rigor of winter is over; that spring is come with its birth of new life, bringing beauty and happiness in its train. And in ourselves, as we recognise the notes of spring, life leaps up with a new sense of the beauty and happiness of living. Those notes, in fact, which began by giving only simple pleasure to our ear, have stirred ideas in our minds; they have become associated in our imagination with a fuller and higher sense of life.