Take for example our familiar Badger (_Meles taxus_). It inhabits Europe and Northern Asia. It is absent apparently from many parts of Central Asia, but it appears again farther south in Palestine, Syria, Persia, Turkestan, and Tibet. West Central Asia would be about the centre of its range. That this corresponds to its place of origin is indicated by the fact that the only three other Badgers known--viz., _M. anakuma_, _M. leucurus_, and _M. albogularis_--are confined to Asia. If we examine the fossil history of the genus, we find that the two most ancient instances of the existence of Badgers have been discovered in Persia, where _M. Polaki_ and _M. maraghanus_ occur in miocene deposits. The latter had migrated as far west as Greece in miocene times; no other trace of the Badger, however, is known from Europe until we come to the pleistocene beds. There are a good many cases known among mammals where the centre of dispersion would indicate to us a similar origin. On the other hand, there may be no fossil evidence of the occurrence of a species, or of its ancestors, in Asia, whilst such has been discovered in Europe. I think, however, that the present range of a species forms a safer criterion for the determination of its original home, as the Asiatic continent is still practically unworked from a palæontological point of view. In a letter which I received from Professor Charles Depéret, he advocates the view that the wild Boar (_Sus scrofa_) is probably of European, and not, as I maintained (_c_, p. 455), of Asiatic origin; because there seemed to be a direct descent from Hyotherium of the middle miocene of Europe, through the upper miocene Pig of the Mount Lebéron (_Sus major_) and of Eppelsheim (_Sus antiquus_), and the pliocene Pigs of Montpellier (_Sus provincialis_) and of the Auvergne (_Sus arvernensis_). No doubt this appears rather a strong case in favour of the European origin of the wild Boar, but although the Tertiary strata of Asia, as I remarked, are as yet little known, a number of fossil pigs are known from India, Persia, and China, the oldest being the upper miocene Persian Pig (_Sus maraghanus_). Pigs are therefore as old in Asia as in Europe, and as a direct intercourse between the two continents probably never ceased since miocene times, it is not surprising that this genus should occur in both. Even if the genus had its origin in Europe, it is quite possible that in later Tertiary times, the active centre of origin was shifted to the neighbouring continent, and that henceforth many new species issued forth from Asia, some of which may subsequently have been modified on reaching our continent. The wild Boar (_Sus scrofa_), however, to judge from its general range, I must look upon as merely an immigrant in Europe. I have no doubt that it originated somewhere in Asia, probably in the south.