Emigration on so large a scale exercises far reaching economic and historical influences.  Norse colonization contributed interesting chapters to the history of Europe in the ninth and tenth centuries.  Norwegians who have flocked to America have made a deep impress upon our Northwestern States.  Switzerland in 1902 and 1903 gave as 9500 of its subjects, a valuable contribution.  Scotchmen of Highland birth are scattered over the whole world, carrying with them everywhere their sturdy qualities of character.  Even the stay-at-home French lose emigrants from their mountain districts.  The people of the Basses-Alps go to Mexico, and the Basques from the French Pyrenees seek Argentine.[1341] The honesty, industry, and frugality of these mountain emigrants make them desirable elements in any colonial population, and insure their success when they seek their fortunes in the uncrowded western world.

The alternative to overpopulation and its remedy emigration is found in preventive checks to increase.  These sometimes take the form of restricted or late marriages, as Malthus found to be the case in Norway and Switzerland in 1799,[1342] before the introduction of steam or electric motive power had stimulated the industries of these countries or facilitated emigration thence.  The same end is achieved by the widespread religious celibacy which sometimes characterizes mountain communities.  In the barren Auvergne Plateau of France, the number of younger sons who become priests is extraordinary.  Many daughters become nuns.  Celibacy, seconded by extensive emigration, clears the field for the eldest son and the system of primogeniture which the poverty of this rugged highland has established as a fixed institution in the Auvergne.[1343] A careful statistical investigation of the geographical origins of the Catholic priesthood in Europe might throw interesting light on the influences of environment.  The harsh conditions of mountain life make the monastery a line of least resistance, while geographical isolation nourishes the religions nature and benumbs the intellectual activities.

It is in the corrugated highland of Tibet, chilled to barrenness by an elevation of 12,000 feet or more (4000 meters), sterile and treeless from aridity, carved by canon-cutting streams into deep gorges offering a modicum of arable soil for irrigation, that monasticism has developed into an effective system to keep down population.  Buddhism, with its convents and lamaseries, naturally recommended itself to a country where asceticism was obviously expedient.  The world shows nowhere else so large a celibate class.  In Tibet, monks are estimated at 175,000 to 500,000 in a total population of three millions.  Archibald Little estimates their number at one-third of the total male population.[1344] Derge, which is the most productive district both agriculturally and industrially of eastern Tibet and is also most densely inhabited, counts at least 10,000 lamas in