124 AGE-INCIDENCE OF CAUSES OF INFANT MORTALITY 



last three months. At this rate, the factor for the ninth month 

 should be about 23.8. In this way we start each series, not with 

 1,000 living infants, but with 1,024 women entering the ninth 

 month of pregnancy regularly through a given month (Decem- 

 ber, for instance), and therefore reaching the first day of the 

 next month (January, for instance), with the date of expected 

 delivery anywhere from one day to 30 days ahead. The first 

 month's mortality will, in this case, include the still-born. 



The only noteworthy change produced by this treatment ap- 

 pears in the January curve. We gain a perception that it is 

 better to be born in winter than in summer, but there is no sub- 

 stantial profit in this statement of the relations. One reflects, 

 however, that Neumann's tables must have included prematurity, 

 which projected, into the population and the mortality of each 

 initial month, non-viables really belonging to the following 

 month, as well as viables with bad chances, complicating the 

 history of the series for several months. With respect to still- 

 births, on the other hand, there must be delay, carrying forward 

 part of the antenatal mortality of each month into the still-birth 

 account of the next month. 



If we should include the whole of antenatal mortality, we 

 should necessarily add to the infant's chances of death the 

 chances of death of the mother. But, since the child's chances 

 of continuing life after birth are seriously impaired by maternal 

 death, and even by maternal disability immediately following 

 childbirth, we can hardly avoid admitting the mother's chances 

 as materially affecting the expectancy of the child. It is possible 

 that greater than August altitude is realized, in December, by 

 December babies whose mothers die in the first three days post 

 partum. 



Maternal death must be required to account for part of the 

 antenatal mortality indicated by Karl Pearson's figures. With 

 respect to the mothers whose offspring make up Neumann's 

 table, it can be asserted that these 199,525 women who were sub- 

 ject before, on, or after the date of their delivery, to a mortality 

 tax on their own lives, and died four or five daily. They were, 

 indeed, the survivors of a large reproductive undertaking, into 

 which there originally entered more than 300,000 women, sub- 

 ject to, and paying, a mortality tax of seven or eight women 

 and more than 350 prospective children daily. Our situation 

 is very much as if the date of birth had somehow eluded us, 

 having variable relations to life and death, and unsettling the 

 conventional preconception of a biologic fixture. It seems better 

 to examine the whole of a reproductive effort to the end of the 

 first year of post-natal life, without particular regard to the 

 date of birth, and allowing that event to define for itself un- 

 prejudiced relations, if not clear ones. 



