Towards the Black Sea coast its thickness diminishes, and it disappears in the valleys.
And it grows, merges, disappears from the surface, sinks to the depths, and again emerges.
In the second case every axle in the train may be made a driving-axle if desired, in which case the locomotive as a separate machine disappears.
Apart from tradition, Samoan is the most archaic of all the Polynesian tongues, and still preserves the organic letter s, which becomes h or disappears in nearly all the other archipelagos.
To the southward, as the valleys become increasingly sandy and saline, even the sage-brush disappears, and little vegetation besides the cactus and the yucca is to be seen.