212 GROVE KARL GILBERT— DAVIS 



Apparently the real reason for the absence of a generic name for the longitudinal streams 

 of the Pueblo quadrangle must be that, here as well as elsewhere, Gilbert had had little 

 experience with such streams. This point has already been adverted to on earlier pages in 

 connection with the open monoclinal valleys developed on weak strata in the great flexures 

 near the Zuni uplift, where the drainage was inconspicuous because the climate was arid; with 

 the short and dry monoclinal valleys behind the piedmont revet crags of the Henry Mountains; 

 ' and with the much more striking example of a self-generated longitudinal stream, Hoxie Creek, 

 which follows the weak beds of the Water-pocket flexure between the Henry Mountains and 

 the high plateaus. True, self-developed monoclinal streams and valleys are numerous, indeed 

 predominant in the Appalachians, where they are often scores of miles in length; but although 

 Gilbert was for a time in charge of the Appalachian division of the national survey, his eastern 

 field work was almost wholly limited to the Great Lakes region of nearly horizontal strata. 

 Thus it would seem as if it was because longitudinal streams following long and narrow outcrops 

 of easily eroded strata had not as a class attracted his attention that he did not give them a 

 technical name; and it is even possible that he did not clearly recognize the few streams of 

 this kind which he had seen as belonging in a class apart from other streams. This conclusion 

 is supported by a brief statement in a review that he wrote in 1883 of McGee's study of streams 

 in Iowa, 10 in the course of which he said : 



It is now many years since Powell first proposed to class all inconsequent drainage as either antecedent 

 or superimposed, and no later writer has added to the number of categories. 



But it is difficult to believe that a man of Gilbert's quality held this opinion in 1895. 



io Drainage system and loess distribution of eastern Iowa. Science, ii, 1883, 762-763. 



