ABSTRACT
As with Egypt and the Nile valley, so it may be also that the civilizations organized in the third millennium before Christ in the Tigris and Euphrates lowland, in the Indus valley and in China were at least in part a necessary development to feed a more concentrated population at a time when huge areas outside those valleys in Arabia, in Afghanistan and Rajastan, and in the Gobi and Sinkiang, were becoming more desert-like. If pastures and stocks of wild game for hunting were failing, the advantages of cultivation in more or less reliably irrigated valleys would be more obvious to those faced with abandoning an ageold way of life.1 The Japanese meteorologist and geographer Hideo Suzuki has made the interesting suggestion that it was the refugee herdsmen and farmers from the increasingly desert regions round about who were fated to become the slaves who made possible the intensive agriculture and the great building works for which ancient Egypt and the other river valley civilizations are famous. But even as man learnt to produce controlled environments for agriculture, he still had to work with the conditions that nature provided.
