(4) The early motherhood of the Negro has its evil effects. The proper age for a woman to become a mother is at twenty-five years and usually before that time development is not complete, and the whole organism is in a transition state. It is equally true that the use of any organ before it has attained its complete growth or development is damaging to that organ and interferes with its normal function, and "we cannot but believe that children developed in immature sexual organs must be deficient in true vital force and energy. It is often noticeable that a child apparently strong and vigorous, may have but little power to resist disease, or may even be strongly predisposed to some infirmity." The colored women in the section under discussion who become mothers, are usually multiporae long before the twenty-fifth year. (5) The element of overwork must come in for its increment of responsibility in the excessive mortality of the Negro. While deficiency in exercise favors a lack of nutrition conducive to wasting in size, on the other hand too much work favors hypertrophy of vital organs and tissue degeneration. The average healthy man should work about eight hours per day and "should do work to the equivalent of 150 foot-tons daily." The American Negro's working hours, as a rule, are regulated, if at all, by the exigencies of the work to be performed, as it appears to an exacting employer. (6) The kind of work performed by the Negroes in the Southern cities includes all menial occupations, which conduce to accident and exposure. The death-rate among the laboring class of any community, irrespective and independent of its nationality, is necessarily greater than that of the well-to-do leisure class.