Comparing the entire old immigration for the period specified with the entire new immigration (European only), we find that of the former 58.5 per cent were male and 41.5 per cent female; of the latter 73 per cent were male, and 27 per cent female.[156] It is evident that the new immigration is in no sense an immigration of families, but of men, either single men, or married men who have left their wives on the other side. This is due in part to the very fact that it is a new immigration, partly to the fact that it is, to such a large degree, temporary or provisional. An immigrant who expects to return to his native land after a few years in America is more likely to leave his wife behind him than one who bids farewell to his old home forever. The typical old immigrant, when he has secured his competency, sends for his wife to come and join him; the typical new immigrant, under the same circumstances, in many cases returns to his native land to spend the remainder of his days in the enjoyment of his accumulated wealth. The only exception to this rule is that furnished by the Hebrews, among whom the sexes are nearly equally distributed. This is one of the many respects in which they stand apart from the rest of the new immigration. The only race in which the female immigrants exceed the males is the Irish, and this has been the case only within recent years. During the years of the great Irish immigration the males predominated. The matter of sex is one of the greatest importance to the United States. It is one thing to have foreign families coming here to cast in their lots with this nation permanently; it is quite another to have large groups of males coming over, either with the expectation of returning ultimately to their native land, or of living in this country without family connections, for an indefinite number of years. Such groups form an unnatural element in our population, and alter the problem of assimilation very considerably. They are willing to work for a lower wage than if they were trying to support families in this country, and are not nearly so likely to be brought into touch with the molding forces of American life as are foreign family groups. Their habits of life, as will appear later,[157] are abnormal, and tend to result in depreciated morals and physique. Many of the most unfortunate conditions surrounding the present immigration situation may be traced to this great preponderance of males.