The survey is saddened by the terrible losses of War, and the even more devastating ravages of influenza; and we realize our inadequacy to prevent catarrhal infections, until further research into preventive possibilities proves successful, and until the standard of universal conduct for catarrhal affections becomes much higher than at present. We realize furthermore that probably at least half the deaths from all causes which occur could be postponed until old age. But the standard of health of the general population has greatly improved; typhus has practically disappeared under peace conditions; yellow fever approaches its demise; malaria and typhoid are controllable; tuberculosis and venereal diseases are only waiting for systematic, complete, and continuous measures to secure their rapid decline or actual disappearance; the mortality from childbearing and of young children has greatly declined; and this is an incomplete statement of what has already been done. _Obstacles_ This improvement is all the more remarkable in view of the additional obstacles imposed to health improvement by modern conditions of urban and industrial life. _Urbanization_ The population during the last century has steadily flocked to the towns from country districts. Streets have taken the place of green fields; rows of unsatisfactory dwellings have replaced country cottages; we have dust and belching smoke and noise instead of sunshine and country air and quiet; bustle and turmoil instead of life in close touch with mother-earth: and this change has been associated with an almost unlimited inter-communication of human beings, and a corresponding increase in opportunities for the convection of germs of disease. Until the time of the industrial revolution in England modes of locomotion were little if any more advanced than among the ancient Egyptians; and disease, when it travelled at all, travelled by slow and deliberate stages. Now the infections of the entire world may be sampled in any one district in the course of a few weeks. Man has, in fact, reverted from the land-tied condition involved in agriculture to the migratory habits of an earlier period of man’s life on the earth. As Wells has put it: “in every locality ... countless people are delocalised,” and it is not the least evil of urbanization that, in consequence of this, the administration of local affairs falls too often “into the hands of that dwindling moiety which sits tight in one place from the cradle to the grave,” or of persons who have a financial axe to grind. The difficulties of water supply, of scavenging, and of drainage, until they were overcome, have made towns the inevitable destroyers of mankind. The conditions of housing are worse in towns than in country districts, higher rents and less ground space implying that each family on an average lives in fewer and more crowded rooms than in rural districts.