SUCCESSIVE STAGES OF CULTURE IN NORTHERN NEW MEXICO. 93 



The final conclusions of Professors Henderson and Robbins are summed up in twelve state- 

 ments, part of which refer to geological matters whose relation to man has not been definitely 

 determined. The others are as follows (pp. 68-9) : 



"1. The climate of the Rito de los Frijoles and surrounding region does not now permit the 

 raising of corn without irrigation except in perhaps a few favored locahties. 



"3. It would not require a very great increase in precipitation to naake the raising of hardy, 

 drought-resisting varieties of corn possible without irrigation in localities where it is not now 

 possible. 



"4. Distribution and extent of ruins throughout the Southwest, including the Jemez Plateau, 

 strongly suggest different conditions a few centuries ago, with a more general distribution of 

 springs and streams and sufficient precipitation for the cultivation of areas not now fit for agri- 

 culture and for the irrigation of tracts where it is now impracticable, thus indicating a probable 

 change of climate within at most the last ten to twenty centuries. There is some direct historical 

 evidence pointing the same way. 



"7. There is some botanical evidence, although meager, of a change in climate within four or 

 five centuries and of the still-continuing desiccation. 



"8. On the whole, in the opinion of the writers, various lines of evidence point to progressive 

 desiccation of the region since the beginning of the pueblo and cHff-dwelling period, with no 

 important evidence inconsistent with this view, although the change in population may possibly 

 be ascribed to other causes. 



"9. This progressive desiccation, if it has occurred, doubtless has been accompanied by 

 numerous shght fluctuations in climatic conditions, just such as are matters of record during 

 historic time, wet and dry and warm and cool cycles alternating. 



"12. Evidence of recent desiccation is not conclusive, but the problem is probably capable of 

 solution by further cooperative investigation along lines suggested in this discussion. Several 

 lines of evidence point to slight progressive desiccation in the Southwest within the period of 

 human occupancy. Such desiccation would satisfactorily account for present conditions, and no 

 other explanation yet suggested seems adequate." 



On the whole, the conclusions of Professors Henderson and Robbins as well as of Dr. Hewett 

 agree with those to which we have been led in the volume. This agreement is important, inas- 

 much as their pubHcation is the first in which independent workers other than the present author 

 have taken up the methods discussed in this volume and have applied them to a region in America. 



