Chandler—A Study in Longevity. 
57 
It is claimed that a comparison of the vital statistics of suc¬ 
cessive periods of time sustains this assertion. But such com¬ 
parisons, as they are usually made 1 , give opportunity for a very 
considerable error which has been avoided in the investigation 
of which the results are here presented. 
Obviously the records of recently organized communities are 
not available for such comparisons, since they cover an insuffi¬ 
cient period of time; and therefore in American investigations 
it has seemed necessary to confine attention to the records of 
those sections of the country which were settled at the earlier 
dates. But from these regions there has been a constant drain 
of the most vigorous elem'ents for the settlement of new com¬ 
munities, with a resulting difference in the physical vigor of 
the two sections sufficiently evidenced by the greater proportion 
of the eastern volunteers in the days of the civil war who were 
rejected by the examining surgeons than of those who were 
thus found physically defective among their western comrades. 
A marked deterioration in physique could hardly have been 
avoided in the regions whence there had been a steady flow 
of vigorous life. 
My former paper presented the results of an examination 
of the successive generations of three Hew England families 
having their membership scattered throughout the country, an 
examination evidently offering no place for the error which 
has been mentioned. The results were such as suggested a 
serious doubt of the correctness of the theory of decreasing 
vigor; but the work did not cover a sufficiently extensive field 
to justify anything more than a suggestion that the conclusion 
based upon the statistics of successive periods taken from, the 
same region had a serious probability of error. 
My present paper is based upon a careful examination of the 
records of eight, families extending back to the beginning of 
the seventeenth century, and containing more than one hun¬ 
dred thousand names, although of course only a rather small 
fraction of the entire number could rightly be used in the com¬ 
putation, not merely because in all genealogical records 
there are numerous failures to give date of either birth or death, 
but also because of the later, and of course much the larger, 
