Probably no other department of the standard of living of the immigrants has received such careful study in recent years as the matter of housing. As a result, we are now able to draw more accurate general conclusions in regard to this matter than is possible in respect to almost any other phase of the standard. Particularly is this true in regard to conditions in the compact colonies of our large cities, which, as we have seen, constitute the characteristic home of the new immigrant, and where the problem is the greatest. There is also a mass of reliable information in respect to another characteristic home of the immigrant, the residence portions of mining camps, and the smaller manufacturing cities. Up to the present the slum, in spite of all the attacks upon it, has maintained itself as a permanent feature of most of our large cities. But the population of the slum is not a permanent but an ever changing one. The unsuccessful, unfortunate, and incapable individuals remain, but the more ambitious, progressive, and successful move on to other and better sections. Nevertheless, the slums are always full; and grow rather than diminish. There is a never failing supply of new recruits, in the body of recent immigrants, to take the places of those who move up. Thus the slum becomes the great sifting ground of the foreign-born, and tends to become more and more the abode of the poorest classes of our population. Not only is there a progression of individuals through the slum, but some of our cities have witnessed a most interesting and significant succession of races along the same course. The natives were displaced by the Irish; they in turn were crowded out by the Italians and Jews, and now the Greeks, Syrians, and allied races are driving out the Italians. Races may come and races may go, but the slum goes on—forever?