NATURAL SELECTION IN MAN 189 
as their age at death increased from 45 to 65-70 years and then to 
decrease somewhat. ‘‘Childless women and mothers of extremely 
small families have shorter expectation of life than mothers of 
moderate sized families.” With families of more than six children 
the mother’s expectation of life diminishes. In a memoir by 
Beeton and Pearson it is remarked: “‘I [K. P.?] think, therefore, 
that we can no longer talk of natural selection as an hypothesis. 
It is in the case of man demonstrably at work either changing in a 
quantitatively definite manner his constitution as a whole or else 
necessary to keep that constitution stable. It is now not correct 
to say as Lord Salisbury said in 1894 of natural selection ‘No man, 
so far as we know, has ever seen it at work.’ It is sensibly and 
visibly at work; a factor in 50 to 80 per cent of the deaths in the 
case of man is not a slight perturbation . . . it is something we 
run up against at once, almost as soon as we examine a mortality 
table.” 
Attempts have been made to demonstrate the workings of 
natural selection by studying the changes occurring in the human 
population of limited districts. Among the most extensive inves- 
tigations in this field are those of O. Ammon upon the inhabitants 
of Baden. The people of this duchy were held to consist mainly 
of two racial elements, a relatively tall, blond, blue-eyed, dolicho- 
cephalic “‘Germanic”’ race, and a small, dark-haired, dark-eyed, 
round-headed ‘‘mongoloid” race. The long-headed types were 
found to prevail more in cities and towns than in the country, and 
the older urban inhabitants were found to be more dolichoceph- 
alic than the recent ones. The long heads being the more intelli- 
gent, superior stock tended to supplant the round heads in the 
cities where the struggle for position depends more than in the 
rural districts upon the possession of superior mental and moral 
qualities. It is the dolichocephalic, according to Ammon, that 
form the aristocratic race, fitted by their superior endowments to 
form a ruling caste. They are found in greater numbers in the 
higher walks of life and they are relatively more abundant in the 
higher than in the lower grades of the gymnasia. In the migra- 
tion of peoples from the country to the city which it is assumed 
