A large number of tables deal with the influence of the numerical position in the progeny, with the number of births and the interval between births, on the health of the children, partly acting alone, partly in combination with the influence of the manner of nourishment during infancy. [Sidenote: C 50] +Numerical position in family and infantile mortality+, after Geissler. According to these statistics, the fifth child of a mother has materially less vitality than the first four, the second and third children have the most; but this does not agree with other statistics. [Sidenote: C 51] According to Riffel's investigations--+influence of the numerical position of the child and the age of the parents at the time of marriage on infant mortality+, after v.d. Velden, a material difference between the mortality of the three earliest born children and the three next born is only shown if both parents at the time of marriage have attained a certain age (man over 28, woman over 25); only the seventh to ninth show under all circumstances a materially greater mortality than the earlier children. The children of more aged parents show a materially greater mortality than those of younger parents. The number of children in a family up to the eleventh has no material influence on infant mortality, only in families with twelve children or more a materially greater number of children perish before the fifth year. [Illustration: Relation of Number of Births to Infant Mortality. Percentage of Deaths to 100 Births. Died during the first year of life. Geissler. 26,429 births to 5,236 marriages of members of Saxon coalminers' funds. (Some still-born infants, and children of marriages to which there were only one or two births, are not included). Died before reaching the age of 0.09 of a year, _i.e._, a little more than a month. [Note: under the first graph in figure] The mortality of the 1st, 2nd, 3rd and 4th child is below the average. Greatest vitality shown by 2nd and 3rd child. [Note: under the second graph in figure] The mortality of the 2nd, 3rd, 4th and 5th child is below the average. Greatest vitality shown by 2nd, 3rd, and 4th child. Figure C 50.] [Illustration: Influence of the Number of Births and the Age of the Parents at the Time of Marriage on Infant Mortality. (From Riffel's Tables, after v. d. Velden). Key to Table ------------ Percentage of Children Born. 1-3 4-6 7-9 Children =================================== ==== ==== ==== { Children of all 28.8 30.5 38.5 { parents. { { Husband over 28 or Died before { wife over 25 years 38.5 41.6 53.4 reaching { old. 6th year. { { Husband over 28 and { wife over 25 years 41.5 51.7 64.7 { old. Influence of the Number of Children Born to a Family on Infant Mortality. 3-5 6-8 9-11 12-15 Children ==== ==== ==== ===== Percentage of children born Died before reaching 5th year 25.5 27.7 22.7 44.3 Figure C 51.] [Sidenote: C 52]