A pure love of change, acting according to some law of contrast as yet imperfectly understood, especially characterises civilised man.  After a long continuance of one mood he wants to throw himself into another for the pleasure of setting faculties into action that have been long disused, but not yet paralysed by disuse, and which have become fidgety for employment.  He has so many opportunities for procuring change, and has so complex a nature that he easily learns to neglect a more deeply-seated feeling that innovation is wicked, and which is manifest in children and barbarians.  To a civilised man the varied interests of civilisation are temptations in as many directions; changes in dress and appliances of all kinds are comparatively inexpensive to him owing to the cheapness of manufactures and their variety; change of scene is easy from the conveniences of locomotion.  But a barbarian has none of these facilities:  his interests are few; his dress, such as it is, is intended to stand the wear and tear of years, and all weathers; it is relatively very costly, and is an investment, one may say, of his capital rather than of his income; the invention of his people is sluggish, and their arts are few, consequently he is perforce taught to be conservative, his ideas are fixed, and he becomes scandalised even at the suggestion of change.

The difficulty of indulging in variety is incomparably greater among the rest of the animal world.  If a pea-hen should take it into her head that bars would be prettier than eyes in the tail of her spouse, she could not possibly get what she wanted.  It would require hundreds of generations in which the pea-hens generally concurred in the same view before sexual selection could effect the desired alteration.  The feminine delight of indulging her caprice in matters of ornament is a luxury denied to the females of the brute world, and the law that rules changes in taste, if studied at all, can only be ascertained by observing the alternations of fashion in civilised communities.

There are long sequences of changes in character, which, like the tunes of a musical snuff-box, are regulated by internal mechanism.  They are such as those of Shakespeare’s “Seven Ages,” and others due to the progress of various diseases.  The lives of birds are characterised by long chains of these periodic sequences.  They are mostly mute in winter, after that they begin to sing; some species are seized in the early part of the year with so strong a passion for migrating that if confined in a cage they will beat themselves to death against its bars; then follow courtship and pairing, accompanied by an access of ferocity among the males and severe fighting for the females.  Next an impulse seizes them to build nests, then a desire for incubation, then one for the feeding of their young.  After this a newly-arisen tendency to gregariousness groups them into large flocks, and finally they fly away to the place whence they came, goaded by a similar