Such plains have been both source and recipient of every form of historical movement.  Owing to their prevailing fitness for agriculture, trade and intercourse, they are favored regions for the final massing of a sedentary population.  The areas of greatest density of population in the world, harboring 150 or more to the square kilometer (385 to the square mile), are found in the lowlands of China, the alluvial plains of India, and similar level stretches in the Neapolitan plain and Po Valley, the lowlands of France, Germany, Holland, Belgium, England and Scotland.  Such a density is found in upland districts (660 to 2000 feet, or 200 to 600 meters) bordering agricultural lowlands, only where industries based upon mineral wealth cause a concentration of population. [See maps pages 8, 9, 559.]

[Sidenote:  Extensive plains unfavorable to early development.]

The level or undulating surface of extensive lowlands is not favorable to the early development of civilization.  Not only do their wide extent and absence of barriers postpone the transition from nomadism to sedentary life, but their lack of contrasting environments and contrasted developments, which supplement and stimulate, puts chains upon progress.  A flat, monotonous relief produces a monotonous existence, necessarily one-sided, needing a complement in upland or mountain.  To the pioneer settlers in the lowlands of Missouri the Ozark Plateau was a boon, because its streams furnished water-power for much needed saw and flour mills.  Treeless Egypt even before 2500 B. C. depended upon the cedars of the Lebanon Mountains for the construction of its ships; so that the conquest of Lebanon, begun by Thutmose I. and completed by Thutmose III. in about 1470 B. C., had a sound geographical basis.[1033] Similarly the exploitation of the copper, malachite, turquoise and lapis-lazuli of Mount Sinai, minerals not found in the Nile plain, led the ancient Egyptians into extensive mining operations there before 3000 B. C., and resulted in the establishment of Egyptian political supremacy in 2900 B. C., as a measure to protect the mines against the depredations of the neighboring Bedouin tribes.[1034] Lowlands lack the distinctive advantages of highlands found in diversity of climate, water-power, generally in more abundant forests and minerals.  The latter are earlier discovered and worked in the tilted strata of mountains and uplands.

Plain countries suffer particularly from a paucity of varied geographic conditions and of resulting contrasts in their population.  Their national characters tend to be less richly endowed; their possibilities for development are blighted or retarded, because even racial differences are rapidly obliterated in the uniform geographic environment, A small diversified country like Crete, Great Britain, Italy, Portugal, Saxony, or Japan, is a geographical multum in parvo.  The western half of Europe bears the same stamp, endowing each country and nation with marked individuality