664 K. PUMPELLY EVOLUTION OP OASES AND CIVILIZATIONS 



It will be interesting also to make a tentative application of the 

 chronological data given in the tables to the strata of alluvial growth 

 penetrated in the Askabad well. 



The rate of growth of the delta alluvium is 0.8 feet per century as 

 compared with culture strata at 2 feet per century. 



An inspection of the record of the boring reproduced on figure 6 will 

 show that between the depths of 500 feet and 1,680 feet the strata of 

 sediments coarser than silts are of the coarsest kinds — large cobble — the 

 long interval between 500 feet and 1,680 feet differing in this respect 

 wholly from the rest of the column, both above and below. 



There can be little question, I think, that the extremely coarse charac- 

 ter of these beds and the frequency of their occurrence in this part of the 

 column indicate for this interval a correspondingly long period of in- 

 creased precipitation, during which the swollen streams were enabled to 

 carry the coarsest constituents of their load farther down their channels, 

 while lateral overflow spread much of the finer silts over the delta-surface. 



It is likely that this part of the column records some of the phases of 

 the Glacial period. It is also possible that the sediments between 320 

 and 1,820 feet grew more rapidly than those of the rest of the column, 

 and that our deduced ratios are applicable only to the upper 320 feet, 

 or to the growth of the last 40,000 years. 



TUEKESTAN AND IRANIA, A EeGION OP INDEPENDENT ETHNIC AND 



Cultural Evolution under Isolation, dating prom Preglacial or 

 Interglacial Time 



In considering the observed data of the earliest of the Anau cultures 

 in their ethnographic relations, one must be struck by a singular fact: 

 They had none of the usual weapons of offense and .defense; the cores 

 from which they made the abundant flint knives arouse our wonderment 

 at the absence of the arrow-points, spear-heads, and axes found in almost 

 all advanced Stone Age and neolithic settlements, as well as of maces 

 and artificially formed sling-stones. Now axes, spear-points, and arrow- 

 points of stone are, throughout the rest of the world, everywhere abun- 

 dant where primitive man has existed, and in the improvement in the 

 manner of their fashioning they serve to mark off the long stages in the 

 slow development of primitive human culture. 



The evolution of these implements from the almost natural shape to 

 highly finished forms, specialized for different uses, was exceedingly 

 slow. This has been proved at several points in Europe, where they 

 have been found in strata of different epochs of the Glacial period and 



