EUGENICS AND EUTHENICS 489 
It is not by accident that inherited longevity in a family is associ- 
ated with low mortality of its children. The connection between the 
two facts was first discovered by Mary Beeton and Karl Pearson in 
their pioneer work on the inheritance of duration of life. They found 
that high infant mortality was associated with early death of parents, 
while the offspring of long-lived parents showed few deaths in child- 
hood. The correlation of the two facts was quite regular, as will be 
evident from a glance at the following tables prepared by A. Ploetz: 
LENGTH OF LIFE OF MOTHERS AND CHILD MORTALITY OF THEIR 
DAUGHTERS (ENGLISH QUAKER FAMILIES, DATA OF 
BEETON AND PEARSON, ARRANGED BY PLOETZ) 
Year oF LIFE in Waicu MorHers DIED Ar 
ALL 
to 38 | 30-53 | 54-68 | 69-83 | 84 up | ACES 
Number of daughters.............. 234 | 304| 395 | 666] 247 | 1,846 
Number of them who died in first five 
VOOTS zp. cis sass 2 Snare aiwnuer oc 122 114} 118 131 26 Sir 
Per cent of daughters who died...} 52.1 | 37-5 | 29.9 | 19.7 | 10.5 | 27.7 
LENGTH OF LIFE OF FATHERS AND CHILD MORTALITY OF 
THEIR DAUGHTERS 
Year oF Lire in Wuica FATHERS DIED At 
ALL 
to 38 | 39-s3 | s4-68 | 69-83 | 84 up | ASES 
Number of daughters.............. 105 284 | 585 797 236 | 2,009 
Number of them who died in first five 
Wears on wscmanea eee ghar acs tee SI 98 | 156] 177 4o | 522 
Per cent of daughters who died...]| 48.6 | 34.5 | 26.7 | 22.2 | 17.0] 26.0 
To save space, we do not show the relation.between parent and 
son; it is similar to that of parent and daughter which is shown in the 
preceding tables. In making comparison with the 340 families from 
the Genealogical Record Office, above studied, it must be noted that 
Dr. Ploetz’s tables include one year longer in the period of child mor- 
tality, being computed for the first five years of life instead of the first 
four. His percentages would therefore be somewhat lower if com- 
puted on the basis used in the American work. 
These various data demonstrate the existence of a considerable 
correlation between short life (drachybioty, Karl Pearson calls it) in 
parent and short life in offspring. Not only is the tendency to live 
long inherited, but the tendency mot to live long is likewise inherited. 
