i88i.] 
Human Complexion and its Causes. 
281 
mainland of Australia, which belongs to the dry temperate 
and dry tropical regions. 
In the Polynesian Islands we find black and light brown 
races living in climates which differ respectively very little, 
if at all. 
The dry tropical regions afford further difficulties. Torrid 
and sub-torrid Africa, outside the equatorial belt, presents a 
black population ; whilst that of tropical China, Annam, &c., 
is yellow, and that of Mexico and Southern Brazil and 
Bolivia brown. Why these differences in regions all hot 
and dry ? 
Many of these difficulties may doubtless be solved by 
taking into account the migrations that have taken place. 
A race may have changed its seat, and not yet have assumed 
the complexion most in harmony with its surroundings. 
Thus the aborigines of South America may, as Mr. Bates 
supposes, have arrived from a colder country, and, unless 
they are previously extirpated, they may develop a darker 
complexion. It is even possible that the white inhabitants 
of the United States and Canada, were it not for the con- 
stant influx of European immigrants, might assume a 
complexion more and more assimilating to that of the Red- 
skins. But on these gradual effects of climate we are still 
very ignorant. Europeans who spend their lives in tropical 
or sub-tropical countries are found to be considerably dark- 
ened ; but their children seem in all authenticated cases to 
revert to the ancestral type. The Arabs, however, who as 
members of the Semitic race are certainly not black by 
origin, are said in Nubia to vie in colour with the most jetty 
negroes. It is even said that there are black Jews on the 
south-western coasts of India. If this statement is capable 
of verification it is of the more value, as the Jews every- 
where keep aloof from other races, and no influence of mixed 
blood need here be suspedted. 
A curious circumstance is that in many civilised countries 
the complexion of the population has darkened within histo- 
rical times, even where there has been no immigration of dark 
races at all adequate to effedt the change. The oldest 
records describe the populations of France, Germany, and 
Britain as fair-haired and of light complexions. The two 
latter countries especially have received an abundant influx 
of population from the north, and from the south but little. 
Yet in Germany the more or less dark-haired individuals 
form a respedtable minority, in Britain probably a majority, 
whilst in France light- or red-haired persons are decidedly 
exceptional. 
vol. hi. (third series.) 
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