THE MIGRATION OF POPULATIONS 79 
means simple. Racial, linguistic, social, and political 
hindrances have to be overcome in order to facilitate 
migration movements. The various peoples of the 
sarth exhibit differences which greatly hinder even 
their adventitious mixing, to say nothing of a thorough 
miscegenation. We are not yet assuredly aware whether 
racial antagonisms are the outward expression of what 
may be called sub-conscious judgments, or are merely 
fatuous prejudices which it is desirable should dis- 
appear. The proper degree of miscibility of different 
populations is by no means easily ascertained. 
The question of migration, therefore, is bound up 
with that of the admixtures of peoples. Were they 
merely geographically divided into groups, but belong- 
ing to the one primitive stock, then no doubt the 
matter would be fraught with much less difficulty than 
the problem actually existing. Anthropological and 
anatomical researches, however, indicate that the 
human race is divided into at least three great groups, 
their facial appearances being aptly described by 
Linnzus as those of the Homo Europeus, the Homo 
Asiaticus, and the Homo Afer. Researches like those 
of A. de Gobineau into the Inequality of Human Races; 
like those of F. Siegert in Mongolism;* of J. and R. L. 
Langdon-Down on the Ethnic Classification of Idiots; 
of G. Pouchet on the Plurality of the Human Race; of 
Sera on the Morphology of Man and of the Primitives;® 
of H. Klaatsch on the Evolution and Progress of Man- 
kind; of L. Macauliffe on the origins of actual man;?3 
of F. G. Crookshank and many others, show unmis- 
takably that the question of the desirability of the 
miscegenation of different peoples is one demanding 
consideration. It is not a mere colour question, but 
one of fundamental characters. 
\ Die mongoloide 1diotie : der Mongolismus. 
2 Giorn. p. la Morf. dell’ Uomo e dei Prim., 1918, 1921, 
Les Origines de I’homme actuel, Paris, 1923.