The Anglo-Indian planter is apt to return from a long sojourn in the East with his skin charged with a dark pigment which no amount of Pears' soap will remove during the rest of his life.

It would be interesting to conduct experiments, on the lines of those of Professor Boas already mentioned, with the object of discovering in what degree the same capacity for amassing protective pigment declares itself in children of European parentage born in the tropics or transplanted thither during infancy.
Correspondingly, the tendency of dark stocks to bleach in cold countries needs to be studied.

In the background, too, lurks the question whether such effects of individual plasticity can be transmitted to offspring, and become part of the inheritance.
One more remark upon the subject of colour.

Now-a-days civilized peoples, as well as many of the ruder races that the former govern, wear clothes.

In other words they have dodged the sun, by developing, with the aid of mind, a complex society that includes the makers of white drill suits and solar helmets.