EDITORIAL 8 1 



migration of gathering-grounds of glacier-ice on the Laurentian 

 highlands, the explanation of many otherwise anomalous circum- 

 stances will yet be found. Any inquiry into the causes of such 

 migration opens a wide field of discussion, including particularly 

 meteorological and possibly changed orographical conditions. 

 Other things being equal, it is obvious that the places in which 

 the accumulation of glacier-ice began would also in all proba- 

 bility be those where the last centers of its dispersion continued 

 longest and ultimately failed. It is very important to trace the 

 migration of these centers from which the ice flowed, and if 

 possible to ascertain the conditions which, in all probability, 

 may have interfered with the coincidence of the initial radiant 

 areas and those marking the close of the epoch of glaciation. 



G. M. D. 

 *** 

 It would appear from the papers of Professors Tarr and 

 Barton read at the recent meeting of the Geological Society at 

 Washington, abstracts of which appear in this number of the 

 Journal, that Professor Salisbury and myself must have invited 

 misinterpretation of our views respecting the former extension 

 of the inland ice-sheet of Greenland by infelicities of expression 

 not altogether evident to us. What we have thus far published 

 has consisted, in the main, of brief statements intended rather 

 to show the bearing of the topography of the coast upon the 

 larger questions of glacial prevalence than to indicate the precise 

 local extension of the ice. In the series of papers entitled 

 " Glacial Studies in Greenland" (not yet complete, having been 

 interrupted to give earlier place to contributions awaiting pub- 

 lication), the specific subject of former glacial extension has not 

 yet been reached. When it shall be, however, we shall not wish 

 to be understood as attempting to map the precise limit of former 

 glaciation on the thousand miles of borderland along which we 

 coasted, but merely as endeavoring to indicate its general limita- 

 tions. We believe, neverthless, that our observations and infer- 

 ences are thoroughly trustworthy in the general sense in which 

 thev are intended to be received, and that thcv are decisive in 



