A. The rule of a greater number of conceptions in Spring observed in temperate regions suffers notable exceptions in tropical and arctic regions. Hence there is a weakening of the idea that in it one should recognise the atavistic heritage of a special season for reproduction which the human race had originally shown, analogous to what one finds to-day in many species of animals. On the other hand, neither the frequency of multiple births, of miscarriages, or of stillbirths, nor the length of life of offspring nor their intellectual capacity show any correlation whatever with the season of conception. The frequency of stillbirths, however, and the length of life of the offspring show a clear correlation with the season of birth, in the sense that those born in temperate seasons show a lower rate for stillbirths and a greater length of life.
B. The age of the mother at the time of parturition does not show any regular influence on the size and weight of the child. It has a very sensible influence on the frequency of miscarriages and of stillbirths; this increases with the increase in age. The age of the mother at the time of marriage exercises a decisive influence upon the vitality of the offspring: the greater the age of the mother at the time of marriage the less will be the vitality of the children.
The age of the father at the birth of his child has some influence on the number of stillbirths among his children. This influence—at any rate above a given age—increases with the increase in the father's age. It can neither be disproved nor affirmed that the age of the father at the time of marriage has an influence upon the vitality of the children; it is certain, however, that if any influence of that kind exists it is much less intense than that exercised by the age of the mother.
There has also been an enquiry as to the effect upon the characters of the offspring exerted by (1) order of birth; (2) difference in age of the parents; and (3) the age of the woman at the first menstruation.
C. Persons who die at a more advanced age have children in greater number and endowed with greater length of life. For some classes of the unfit (mad, consumptives, suicides) it can be proved beyond question that the number of children born is less and their mortality greater than among married people generally. Those who die of heart disease or of cancer show a number of children slightly higher than the general average of married persons; but that can be attributed to the fact that their age at death is greater than the average age at death of married people.
[MATERNITY STATISTICS OF THE STATE OF RHODE ISLAND, STATE CENSUS OF 1905.]
(Abstract.)
By Frederick L. Hoffman, LL.D., F.S.S.,
Statistician of the Prudential Insurance Company of America.
As a contribution to the practical study of eugenics the decennial maternity statistics of Rhode Island are of exceptional interest and importance.