Rhine interlace, with the physically different German of the Baltic lands. The same is true of Kentishman, Cornishman, and Yorkshireman in England.
In dealing, not with groups of human beings in simple and primitive relations, but with highly complex, highly specialized, civilized, or semi-civilized societies, there is need of great caution in drawing analogies with what has occurred in the development of the animal world. Yet even in these cases it is curious to see how some of the phenomena in the growth and disappearance of these complex, artificial groups of human beings resemble what has happened in myriads of instances in the history of life on this planet.
Why do great artificial empires, whose citizens are knit by a bond of speech and culture much more than by a bond of blood, show periods of extraordinary growth, and again of sudden or lingering decay? In some cases we can answer readily enough; in other cases we cannot as yet even guess what the proper answer should be. If in any such case the centrifugal forces overcome the centripetal, the nation will of course fly to pieces, and the reason for its failure to become a dominant force is patent to every one. The minute that the spirit which finds its healthy development in local self-government, and is the antidote to the dangers of an extreme centralization, develops into mere particularism, into inability to combine effectively for achievement of a common end, then it is hopeless to expect great results. Poland and certain Republics of the western hemisphere are the standard examples of failure of this kind; and the United States would have ranked with them, and her name would have become a byword of derision, if the forces of union had not triumphed in the Civil War. So, the growth of soft luxury after it has reached a certain point becomes
