This difference in standards is undoubtedly due in part to a difference in natural instincts and aptitudes for decency and cleanliness between the common classes of northern and southern Europe, but probably more to the customary standards to which they have become habituated in their native land. The effect is the same, whatever the cause. The new immigrant desires a certain improvement in his standard as a reward for emigration, but the new standard need not be by any means the equivalent of that of the immigrant races which have preceded him. As long as we continue to draw our immigrants from more and more backward and undeveloped nations and races we may expect to see a progressive degradation in the customary standard of the working people. There are many other considerations besides congestion which determine the character of life in the slums. Many of these have already been suggested in preceding paragraphs. Prominent among them are ventilation, sanitary and cooking facilities, light, water supply, healthfulness of surroundings, and play room for children. The degree in which evils exist in these particulars, in any locality, depends primarily upon the stringency of the local tenement and public health laws, and the energy and faithfulness of their enforcement. Much is being accomplished and has been accomplished in recent years in the direction of securing better conditions. Yet there is almost infinite room for improvement. The futility of relying upon the individual benevolence and humanity of builders, owners, and agents was demonstrated long ago. Here, of all places, eternal vigilance on the part of the better classes of society is the price of safety. Descriptions of the homes of the foreign-born are full of accounts of dark and absolutely unventilated bedrooms, houses unprovided with any water supply, filthy outdoor closets and privy vaults, toilets used by ten or twelve families conjointly, buildings covering the entire lot, dooryards flooded with stagnant water and refuse, basements half filled with water, domestic animals sharing the limited accommodations with the family, and a host of other horrors. Detailed descriptions of these dwellings are unnecessary. Any one interested may find them in abundance in the accounts of housing conditions in the poorer sections of our cities and towns, for, as the Immigration Commission has amply demonstrated, the slum, wherever found, is distinctively the home of the foreign-born.[214]