20 
Pigmentation, Susceptibility and Race Selection 
at the most to give rise to only a very small error, where the comparison is 
based on the pigmentation of the hair and eyes. 
Ripley* states that a great defect in all such investigations on children lies in 
the tendency to a darkening of the hair and eyes with growth ; that from 10°/ 0 — 
20°/ o of blonde children at maturity develop darker hair or eyes. Beddoe")" remarks, 
however, that the broad results are not affected by this flaw. He gives statistics 
of school children under and over 11 years of age, showing a very slight augmenta- 
tion of the darker colours in the older children. Pearsonj, collating statistics, 
concludes that there is little change in hair or eye colour in children under 14, 
but after 14 there is even before 19 a more marked change, the correlations still, 
however, remaining low. This change is much more considerable in the case of 
hair than of eye colour, though sensible in both. Commenting on Dr Pfitzner's 
results on the pigmentation of the hair and eyes of children in Lower Elsass, he 
states that they are quite comprehensible if there be a positive correlation be- 
tween fairness and disease in childhood, and that this is exactly what British school 
children show — tliere is a correlation between health and darkness of hair colour. 
" Hence if we do not follow up individuals, noting their pigmentation at different 
ages, but simply correlate age of different individuals with hair colour, we are 
liable to exaggerate the correlation between age and pigmentation, and this will 
be especially the case if we use hospital returns. Hence it is probable that our 
neglect of a selective death rate, based upon the known correlation between 
general health and pigmentation, really emphasises the values found for correlation 
between pigmentation and age. Further, while it is probable that if we take 
adult life into account we should find this correlation increased, the value deduced 
from Pfitzner's observations may be safely considered to mark in the first place a 
selective death rate, i.e. a correlation between fitness in childhood, and dark pig- 
mentation." 
In conclusion Pearson, commenting on a table exhibiting the results for age 
and hair and eye colour of British school girls from 7 — 19 years of age, states that 
" it would seem doubtful, having regard to the paucity of individuals dealt with, 
whether we can assert significant changes in the percentages of medium-eyed girls 
having fair or brown hair at different ages. Nor would it be wise to insist that 
the changes of percentages in red-haired girls with light or dark eyes are signifi- 
cant. Red-haired girls with medium eyes seem to become continuously fewer with 
age : light-eyed girls with fair hair become significantly fewer, and brown-haired 
girls with light eyes more numerous. Dark-eyed girls with fair or brown hair be- 
come significantly fewer and dark-eyed girls with dark hair become more numerous, 
and probably light-eyed girls with dark hair also. The medium-eyed girls with 
dark hair remain much the same in percentage. Thus, except in the case of red- 
haired girls, those with medium eye colour change least ; the fair-haired girls with 
* Ripley: The Races of Europe, p. 222. 
f Beddoe: The Races of Britain, p. 77. 
X Pearson: "Miscellanea." Biometrika, Vol. in. pp. 464, 465. 
