T H E AREA OF CHINA is roughly 3,860,000 square miles. This huge land mass embraces a wide variety of climates ranging from the tropical in the extreme Southeast to the continental in the Northeast and the Northwest. Over 90 per cent of the country is in the north temperate zone, but the high summer temperatures combined with the heavy summer rainfall in the North and Northeast, amounting to 50 per cent of the annual total, make the widespread cultivation of rice and cotton practicable. The country is extremely mountainous with about three-fifths of the land lying more than 6000 feet above sea level, over a quarter consisting of valleys and the remainder of steppes, desert and oasis.