Having thus laid before you the general lines on which I propose to deal with problems relating to race and nationality, I propose now that we should make a lightning trip round the world and cull, as we go, samples which will illustrate the kind of friction which arises wherever races or nationalities come into close contact. As I have already said, every country can yield us material for our study, but none on such a vast experimental scale as the United States of North America; we shall therefore commence our hurried survey in that country. Within the frontiers of the States is massed a population of 110 millions. When we look closely we see that over ten millions of these inhabitants are marked off from the rest by a frontier, a colour line, as sharply defined and jealously guarded as the frontiers of a kingdom. Across that racial frontier all legitimate social traffic is barred, the custodians of the frontier being those who stand on the white side of the line. Any at...