With this peculiarly uninviting coast line and the difficulties in interior segregation must be considered the climate of Africa. While there is much diversity and many salubrious tracts along with vast barren wastes, yet, as Sir Harry Johnston well remarks, “Africa is the chief stronghold of the real Devil—the reactionary forces of Nature hostile to the uprise of Humanity. Here Beelzebub, King of the Flies, marshals his vermiform and arthropod hosts—insects, ticks, and nematode worms—which more than in other continents (excepting Negroid Asia) convey to the skin, veins, intestines, and spinal marrow of men and other vertebrates the microorganisms which cause deadly, disfiguring, or debilitating diseases, or themselves create the morbid condition of the persecuted human being, beasts, bird, reptile, frog, or fish." The inhabitants of this land have had a sheer fight for physical survival comparable with that in no other great continent, and this must not be forgotten when we consider their history.
 Von Luschan: in Inter-Racial Problems, p. 16.
 Johnston: Negro in the New World, pp. 14-15.
The movements of prehistoric man can be seen as yet but dimly in the uncertain mists of time. This is the story that to-day seems most probable: from some center in southern Asia primitive human beings began to differentiate in two directions. Toward the south appeared the primitive Negro, long-headed and with flattened hair follicle. He spread along southern Asia and passed over into Africa, where he survives to-day as the reddish dwarfs of the center and the Bushmen of South Africa.
Northward and eastward primitive man became broader headed and straight-haired and spread over eastern Asia, forming the Mongolian type. Either through the intermingling of these two types or, as some prefer to think, by the direct prolongation of the original primitive man, a third intermediate type of human being appeared with hair and cranial measurement intermediate between the primitive Negro and Mongolian. All these three types of men intermingled their blood freely and developed variations according to climate and environment.
Other and older theories and legends of the origin and spread of mankind are of interest now only because so many human beings have believed them in the past. The biblical story of Shem, Ham, and Japheth retains the interest of a primitive myth with its measure of allegorical truth, but has, of course, no historic basis.