His next business is to master the main facts about the natural conditions to which each people is subjected--the climate, the conformation of land and sea, the animals and plants.

From here it is but a step to the economic life--the food-supply, the clothing, the dwelling-places, the principal occupations, the implements of labour.

A selected list of books of travel must be consulted.

No less important is it to work steadily through the show-cases of a good ethnological museum.

Nor will it suffice to have surveyed the world by regions.