A study of economic conditions shows that from fifteen to seventeen per cent are dependent, from sixty to seventy per cent are rated as marginal, and from eleven to thirteen per cent as being in comfortable circumstances. In Massachusetts and New York about eighty-five per cent of the admissions come from a city environment and from twelve to fifteen per cent from rural communities. It is interesting to note that in 1919 eighteen per cent of the admissions in Massachusetts and New York were reported as being intemperate in their habits, with over fifty per cent abstinent. In conclusion, it may be said that the important etiological factors in the production of mental disease are heredity, senility, syphilis, arteriosclerosis, somatic diseases, mental deficiency, epilepsy, diseases of the brain and nervous system, alcoholism, drugs, traumatism and mental stress and shocks of various kinds. It is hardly necessary to add that our information on this subject is far from complete. CHAPTER IX IMMIGRATION AND MENTAL DISEASES A history of the development of our western civilization is very largely a study of the process of assimilation of the various racial elements representing a new population. While it must be conceded that we are indebted to European countries for much that has been contributory to the welfare and success of American institutions, it is equally true that the tremendous increase in mental diseases and defects here is to be attributed in no small degree to immigration. This constitutes a problem of social and economic importance which is worthy of serious consideration. Perhaps no better evidence of this fact can be offered than a study of such statistics as are available relating to the thirty-three millions of people coming to the United States from other countries during the last century. This would seem to be particularly indicated at this time, in view of the fact that the conclusion of the war has brought about the necessity of a new adjustment of our relations with other countries.