Such are the two extremes. Where intermarriage takes place between stocks relatively near together, as in crossings between the main divisions of the white species, the result may not be bad, and is sometimes distinctly good. Nevertheless, there is no true amalgamation. The different race-characters remain distinct in the mixed offspring. If the race-types have generally intermarried, the country is really occupied by two or more races, the races always tending to sort themselves out again as pure types by Mendelian inheritance. Now one of these race-types will be favored by the environment, and it will accordingly tend to gain at the other's expense, while conversely the other types will tend to be bred out and to disappear. Sometimes a modification of the environment through social changes will suddenly reverse this process and will penalize a hitherto favored type. We then witness a "resurgence," or increase, of the previously submerged element. A striking instance of this is going on in England. England is inhabited by two race-stocks--Nordics and Mediterraneans. Down to the eighteenth century, England, being an agricultural country with a cool climate, favored the Nordics, and but for the Nordic handicaps of war and migration the Mediterraneans might have been entirely eliminated. Two hundred years ago the Mediterranean element in England was probably very small. The industrial revolution, however, reversed the selective process, and to-day the small, dark types in England increase noticeably with every generation. The swart "cockney" is a resurgence of the primitive Mediterranean stock, and is probably a faithful replica of his ancestors of Neolithic times. Such was the ominous "seamy side" of nineteenth-century civilization. The regressive trend was, in fact, a vicious circle. An ill-balanced, faulty environment penalized the superior strains and favored the inferior types; while, conversely, the impoverishing race-stocks, drained of their geniuses and overloading with dullards and degenerates, were increasingly unable to evolve environmental remedies. Thus, by action and reaction, the situation grew steadily worse, disclosing its parlous state by numberless symptoms of social ill-health. All the unlovely _fin de siècle_ phenomena, such as the decay of ideals, rampant materialism, political disruption, social unrest, and the "decadence" of art and literature, were merely manifestations of the same basic ills.