(W. A. P.)
[1] H. Wagner’s edition of Guthe’s Lehrbuch der Geographie (5th ed., Hanover 1882).
[2] At the summit of each of the Trans-Ural railways (Perm-Tyumen and Ufa-Chelyabinsk) and that of the road across the Caucasus from Vladikavkaz to Tiflis, sign-posts, with the name Europe on one side, Asia on the other, mark this boundary.
[3] Fifth edition, vol. ii. pp. 24-25.
[4] Pt. i. pp. 11-12.
[5] Griesbach, on the strength of Middendorff’s observations, remarks that, in addition to European fruit trees, oak, maples, elms, ashes and the black alder do not cross the Urals, while the lime tree is reduced to the size of a shrub (La Végétation du globe, translated by Tchihatchef, i. p. 181).
[6] On the history of the boundary between Asia and Europe see F.G. Hahn in the Mitteilungen des Vereins für Erdkunde zu Leipzig (1881), pp. 83-104. Hahn, on the ground that true mountain systems must be regarded as forming geographical units, pronounces against the practice of making “natural boundaries” run along mountain crests, and assigns the whole of the Caucasus region to Europe as all belonging to such a system, but orographically quite different from the Armenian plateau (p. 103). But surely it is no less different from the European plain.
[7] Petermanns Mitteilungen (1890), p. 91.
[8] See Supan’s Physische Erdkunde, 4th ed., pp. 376-377, and the authorities there quoted.