north, and gradually under changed climatic conditions the type changed from area to area, and they all still continued to speak the same Indo-European tongue, but with dialectic variations, these also being no doubt due to the physical changes in the vocal organs produced by environment.
If we turn from man to the other animals we find a complete demonstration of this doctrine. For instance, the conditions which have produced a blond race on the Baltic have probably produced the white hare, white bears, and the tendency in the stoat and the ptarmigan to turn white in winter, whilst in the same regions of Europe and Asia the indigenous horses were of a dun color, who not only turned white in winter, but had a great tendency to turn white altogether. It may be objected that the Lapps and Eskimo are not tall and blond, but, on the contrary, short and dark; but they live within the arctic circle in regions where the sun does not shine at all for a great part of the year, and consequently they are quite outside the conditions of environment under which the tall blond race of North Germany has long dwelt. Of course, in dealing with man we are always confronted with the difficulties arising from his migrations; but if we can find a family of lower animals who can not be said to have thus migrated, and who show the effects of environment, we shall be able to argue powerfully from analogy.
The horse family supplies the example required. If we follow it from northern Asia to the Cape of Good Hope, we shall find that every belt has its own particular type, changes in osteology as well as in coloration taking place from region to region. First we meet the old dun horse, with its tendency to become white, the best European examples of which were probably the now extinct ponies of the Lofoden Isles. In Asia, Prejvalsky's horse is the best living instance—a duncolored animal with little trace of stripes. Bordering on the Prejvalsky horse, or true tarpan, come the Asiatic asses: first the dzeggetai of Mongolia, a fawn-colored animal, the under parts being Isabella colored; then comes the kiang of the Upper Indus Valley, seldom found at a lower altitude than 10,000 feet, rufous brown with white under parts, whilst, as might be expected from its mountain habitat, its hind quarters are much more developed in length and strength than in the asses of the plains. The Onager indicus, onager and hemippus are found in all the great plains of the Punjab, Afghanistan, western India, Baluchistan, Persia and Syria, whilst a few are said to survive in South Arabia. All these are lighter in color than the kiang, the typical onager being a white animal with yellow blotches on the side, neck and head. All the Asiatic asses are distinguished by the absence of any shoulder stripe, though they occasionally show traces of stripes on the lower parts of the legs. The southern Asiatic asses just de-
