In this way Saracen armies soon after the death of Mohammed Arabized the whole eastern and southern sides of the Mediterranean from Syria to Spain, and Arab merchants set the stamp of their language and religion on the coasts of East Africa as far as Mocambique.

The handful of Spanish adventurers who came upon the relatively dense populations of Mexico and Peru left among them a civilization essentially European, but only a thin strain of Castilian blood.

Thus the immigration of small bands of people sufficed to influence the culture of that big territory known as Latin America.
[Sidenote: Ethnic intermixture.] That vast sum of migrations, great and small, which we group under the general term of historical movement has involved an endless mingling of races and cultures.

As Professor Petrie has remarked, the prevalent notion that in prehistoric times races were pure and unmixed is without foundation.

An examination of the various forms of the historical movement reveals the extent and complexity of this mingling process.
In the first place, no migration is ever simple; it involves a number of secondary movements, each of which in turn occasions a new combination of tribal or racial elements.