The displacement of the English, Irish, Welsh, and German miners in the anthracite region of Pennsylvania by Italians and Slavs is a familiar fact.[307] The Italians are being driven out of the boot-blacking business, and other of their characteristic trades, by the Greeks. The Irish laborers on the railroads have been largely supplanted by Italians, Slavs, and Greeks. The “Bravas,” or black Portuguese, have forced the Poles, Italians, and, in large measure, the Finns from the cranberry bogs of Massachusetts.[308] Granite City and Madison, Illinois, have witnessed a succession of English, Irish, German, Welsh and Polish, Slovak and Magyar, Roumanian, Greek, and Servian, Bulgarian and Armenian laborers in their industries.[309] In these cases it is plain that while some of the displaced individuals have gone into other, very likely higher, occupations, the real substitution has been the concomitant of a cessation of immigration from the older sources. The north Europeans, being unwilling to meet the competition of races industrially inferior to them, have either ceased emigrating in large numbers, or else are going elsewhere. At any rate they do not come here. The diminution of the supply of native labor has been brought about in an analogous way, though in this case the restrictive forces operate upon the principles of reproduction instead of immigration. Even though it be granted that the numerical supply of labor has been somewhat increased, there has been an undeniable decrease in the efficiency of the individual laborer, as is attested by the uniformly superior earnings received by the native-born as compared with the foreign-born, or the old immigrant as compared with the new. As Dr. Peter Roberts has pointed out,[310] there seems to be a sort of Gresham’s law which operates in the field of labor. The fittest to survive in an unregulated economic competition of races is the one least advanced in culture, the one whose demands in respect to comforts and decencies are lowest, even the one, it sometimes seems, whose industrial productiveness per individual is lowest. It is this fact which gives so dark an aspect to the industrial future of the United States under unregulated immigration.[311]