Every reader must feel the truth of this. What is meant by coming 'to feel at home' in a new place, or with new people? It is simply that, at first, when we take up our quarters in a new room, we do not know what draughts may blow in upon our back, what doors may open, what forms may enter, what interesting objects may be found in cupboards and corners. When after a few days we have learned the range of all these possibilities, the feeling of strangeness disappears. And so it does with people, when we have got past the point of expecting any essentially new manifestations from their character. The utility of this emotional effect of expectation is perfectly obvious; 'natural selection,' in fact, was bound to bring it about sooner or later. It is of the utmost practical importance to an animal that he should have prevision of the qualities of the objects {79} that surround him, and especially that he should not come to rest in presence of circumstances that might be fraught either with peril or advantage,--go to sleep, for example, on the brink of precipices, in the dens of enemies, or view with indifference some new-appearing object that might, if chased, prove an important addition to the larder. Novelty _ought_ to irritate him. All curiosity has thus a practical genesis. We need only look at the physiognomy of a dog or a horse when a new object comes into his view, his mingled fascination and fear, to see that the element of conscious insecurity or perplexed expectation lies at the root of his emotion. A dog's curiosity about the movements of his master or a strange object only extends as far as the point of deciding what is going to happen next. That settled, curiosity is quenched. The dog quoted by Darwin, whose behavior in presence of a newspaper moved by the wind seemed to testify to a sense 'of the supernatural,' was merely exhibiting the irritation of an uncertain future. A newspaper which could move spontaneously was in itself so unexpected that the poor brute could not tell what new wonders the next moment might bring forth.