The white horse has been saved from the wolves by man, but the secondary, tertiary and quarternary colours are also very largely the result of man's work in crossing the primitive strains of Europe with the imported African Bay within the last couple of thousand years.
MIGRATION. The Romans imported millions of negro slaves who have not left a trace of their blood in Europe. Wave after wave of Blonde Migration from the Baltic has conquered the Mediterranean states, but left no fair descendants. The negroes become extinct in Europe. The blondes become extinct on the Mediterranean.
Correcting by sunlight
And so with horses. Imported horses fail to breed healthfully in the damp provinces of India and Brazil, while horse sickness makes a clean sweep of them in many parts of Africa. It is probable, with horses as with men, that no sudden importation to regions outside their native zone of sunlight results in permanent healthy breeding. The imported strain dies out unless it is constantly renewed. Hordes of Asiatics with Dun horses have swept from time to time into Europe, and into India, but Dun horses are scarce in both regions, and do not exist in large numbers except in Scandinavia and in Katywar.
So the strong action of man in sudden floodings of Europe with Bays from the desert, Duns from the steppe, is outweighed by a stronger law of nature. With strains of horses as with tribes of man, the penalty for sudden migration from their native zone of light is gradual extinction.
Yet is there one difference between Bays and Duns. The Dun is not worth renewing, and so dies out unnoticed. The Bay is worth breeding and so persists.
PART IX. THE BRAND OF EUROPE.
The brand of Europe
In nature's immense and gentle processes, throughout the amazing story of the Europe horse, the bewildering actions of forgotten tribes of men, and the sun's own slow adjustments, a single force persists in branding the stock with a sign of ownership.