ABSTRACT
Introduction As pointed out in an early chapter it seems likely that the first villages grew up in the irrigable regions of south-west Asia. If we turn to the period of great migrations in historic times we observe that the rivers were often corridors of advance into the unoccupied territory. In Europe the Danube led the Alpine races into the centre and west of Europe. In North America the French advanced along the St. Lawrence and the great Lakes, and then swept to the south down the Mississippi as far as its mouth. Joliet and Marquette reached the Arkansas River in 1673, and La Salle reached the Gulf of Mexico in 1682. In South America the Amazon flows through hot steamy selvas, and is still not occupied in much of its course by progressive peoples. But such settlement as exists in these tropical forests is close to the rivers in every case. In more clement climes to the south we find the La Plata and its tributaries playing a dominant role here as in the northern hemisphere. In Australia it is a curious fact that the mouth of the Murray-the sole important riverwas the last stretch of the whole coast to be charted (in 1802). But the country along the Murray and the Darling was occupied by pastoralists long before any one lived in much of the vast semi-arid regions nearer the coast of New South Wales.
