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220 Disintegration has penetrated the rock far below the surface and the large crystals are held together with but little more tenacity than prevails in a bed of gravel. Moisture and even roots penetrate it deeply and readily and the crystals fall apart with thrusts of the knife blade, the rock crumbling with the greatest freedom. Roadways have been extensively carved along the sides of the hills with the aid of only pick and shovel. Close examination of the rock shows that layers of sediment exist between the crystal faces, either washed down by percolating rain or formed through decomposition of the crystals in place. The next illustration, Fig. 119, shows how large the growth on such soils may be, and in Fig. 120 the vegetation and forest growth are seen coming back, closely covering just such soil surfaces and rock structure as are indicated in Figs. 118 and 119.

Fig. 120.—Forest and herbaceous growth coming back over such soil conditions as are seen in Figs. 118 and 119. Reforestation tract, Tsingtao, Shantung.

These views are taken on the reforestation tract at Tsingtao but most of the growth is volunteer, standing now protected by the German government in their effort to see what may be possible under careful supervision.