On the other hand, east of the Pripet Marshes the long periods of trying climate, coming regularly in winter and in summer, limit, for the folk who have to live unprotected lives, the possibilities of the effective vigilance and criticism whereby the western European organizations are kept going. There is actual pressing need of a routine of tradition on which to fall back in these times of stress. There is also the fear of the grassland tribes tending to keep the people organized on a traditional basis as war leaders and labourers, while the distance from the sea diminishes trade and the middle class, and helps to maintain localism, which in its turn strengthens routine. There we thus find typically a middle class largely immigrant and alien to the military and labouring classes, and this further complicates the problems of social development and organization. Europe, east and west, thus shows striking contrasts which have fateful consequences; there are also contrasts of importance between north and south. The latitude of most of Europe is such that the sun's rays strike the soil too obliquely to act chemically upon it with sufficient rapidity to decompose fresh material for plant growth as fast as plants use it up. In the Mediterranean {8} region this is hardly the case, but in several parts the soil possibilities are very indifferent, so that our contrast is more between Europe and the Tropics than between north and south in Europe, though it is a valuable clue to many of the differences between the German plain and the Paris basin. Broadly we may say that our latitude has made a really self-dependent agriculture almost an impossibility for Europe, and we note in illustration that Bohemia is suffering sadly because foreign fertilizers could not be imported in 1914-18. The problem of diminishing fertility has made itself insistent again and again in European life, and has proved a goad to drive men to agricultural experiment on the one hand and to trade as a supplementary source of wealth on the other. The contrast between Europe and many parts of China in this respect is a profitable study, if we do not exaggerate, as is so often done, the supposed stagnation of the Orient. From trade the men of Europe have been lured on into large-scale industry with the application of coal, oil, water, and sundry other forms of power in immense amounts. The opportunities for domination and consequently exploitation which this has brought are working out fatefully for us all in many varieties of hurtful contacts, needing humanization most urgently if the situation is to be saved for our children.