PREFACE. XXXII 
support nomadic shepherd life, could not have begun until all of Central 
Asia had become peopled up to the limit of that capacity. 
We may imagine the great area to have been by this time portioned 
out among peoples of varied racial origin and having different degrees of 
culture, varying from nomads in the arid regions to more or less settled 
pastoral peoples with elementary agriculture in the more favored lands 
north of the Black Sea. The waves of movement, beginning in the drier 
eastern region, should seem to have progressed outward, the central peoples 
pushing the next outer ones outward, and so on till the climatically favored 
peripheral regions, including Europe, were successively submerged by one 
migration after another, ending with the purely Turanian inroads of our era. 
These migrations were destructive wherever they came in contact with 
cultures higher than their own. 
The reader will see that in tracing back to Central Asia the source of 
the fundamental elements of western civilization, in finding the traces and 
cause of the inland sea, in discovering evidence of progressive desiccation 
(and in this the cause of the migrations that revolutionized the world), the 
dream has to this extent been realized. 
On the other hand, as regards the Aryan problem, we have contributed 
only some fragments which may be useful in further speculation. The 
solution of the great problem awaits much more extended archeological, 
anthropological, and philological research. 
Our indebtedness is indeed very great for aid and hospitality received 
on this expedition, as it was in that of 1903. In England our ambassador, 
the Hon. Joseph H. Choate, smoothed the way through Turkey with a letter 
from the Turkish ambassador. Prince Hilkof again placed at our disposal 
for the season a commodious private car. In St. Petersburg my plans were 
again generously furthered in many ways by Messrs. Tschernyscheff, Director, 
and Karpinski, Bogdanovitch, and Andrusof, members of the Imperial 
Geological Survey, while General Artamonof, of the General Staff, kindly 
aided me in getting War Office maps of Turkestan. J am under deep obli- 
gation to Count A. Bobrinski and Mr. Latichef, of the Imperial Archeo- 
logical Commission, and Professor W. Radlof, President of the Central 
Committee for Central-Asiatic excavation, for the obtaining from the Gov- 
ernment permission to excavate. Mr. Salemann kindly examined the few 
Uigur and Pehlevi inscriptions found at Merv, and to Mr. Markof we owe the 
important determination of the coins found at Merv. 
In Tiflis the personnel of the expedition were delightfully entertained 
with dinners and a ball by the Georgian Prince and Princess Begtabegof. 
In Turkestan at Kraznovodsk we enjoyed again the hospitality of Colonel 
and Madame Volkovnikof. At Askhabad General Ussakofski, governor of 
