A recent writer (Mr. Ellsworth Huntington) has expressed in picturesque and convincing language the nature of the relationship which has ever existed between man and his physical environments in Asia, and has illustrated the effect of certain pulsations of climate in the movement of Asiatic history. The changing conditions of the climate of High Asia, periods of desiccation and deprivation of natural water-supply alternating with periods of cold and rainfall, acting in slow progression through centuries and never ceasing in their operation, have set "men in nations" moving over the face of that continent since the beginning of time, and left a legacy of buried history, to be unearthed by explorers of the type of Stein, such as will eventually give us the key to many important problems in race distribution. But more important even than climatic influence is the direct influence of physical geography, the actual shaping of mountain and valley, as a factor in directing the footsteps of early migration. Nowadays men cross the seas in thousands from continent to continent, but in the days of Egyptian and Assyrian empire it was that straight high-road which crossed the fewest passes and tapped the best natural resources of wood and water which was absolutely the determining factor in the direction of the great human processions; and although change of climate may have set the nomadic peoples of High Asia moving with a purpose more extensive than an annual search for pasturage, and have led to the peopling of India with successive nations of Central Asiatic origin, it was the knowledge that by certain routes between Mesopotamia and Northern Afghanistan lay no inhospitable desert, and no impassable mountain barrier, that determined the intermittent flow from the west, which received fresh impulse with every conquest achieved, with every band of captives available for colonizing distant satrapies. To put it shortly, there was an easy high-road from Mesopotamia through Persia to Northern Afghanistan, or even to Seistan, and not a very difficult one to Makran; and so it came about that migratory movements, either compulsory or voluntary, continued through centuries, ever extending their scope till checked by the deserts of the Indian frontier or the highlands of the Pamirs and Tibet, or the cold wild wastes of Siberia. Thus Afghanistan and Baluchistan, the countries with which we are more immediately concerned, were probably far better known to Assyrian and Persian kings than they were to the British Intelligence Office (or its equivalent) of a century ago. The first landward explorations of these countries are lost in pre-historic mists, but we find that the first scientific mission of which we have any record (that which was led by Alexander the Great) was well supplied with fairly accurate geographical information regarding the main route to be followed and the main objectives to be gained.