•202 DAVIS— ANTARCTIC GEOLOGY. [April 22, 



mations of former polar sea would be almost as significant as the 

 ■occurrence of fossil land plants in the continental formations of 

 high latitudes. 



It is certainly very suggestive that the stratified formations of 

 high latitudes have already repeatedly yielded evidence of mild 

 climates, chiefly as above noted in the form of fossil land plants 

 contained in continental formations, partly in the form of red sand- 

 stones ; and it is certainly striking that little or no evidence of ancient 

 glacial climates in the polar regions has been found either in con- 

 tinental formations in the form of tillite lying on striated rock- 

 floors, or in marine formations in the form of coarse materials 

 scattered through fine-textured sediments. The inference thus 

 warranted in favor of not infrequent mild polar climates ought to be 

 followed up by critical examination of all pertinent evidence, such 

 as the detailed structure of non-fossiliferous continental forma- 

 tions in high latitudes may furnish. 



Antarctic exploration is of particular importance in this respect; 

 for the Antarctic regions are today at least of continental habit, in 

 ■contrast to the Arctic regions which are, on the other hand, of 

 ■oceanic habit. Speculations are already abundant as to the 

 formerly much greater extension of Antarctic lands, so as to form 

 connections with other continental masses ; and on the present 

 remnant of so greatly extended an area, the possibility of finding 

 continental formations is increased. It therefore seems fitting to 

 bring this matter before that Society which, more notably than 

 any other in the United States, has recently taken active steps in 

 promoting American participation in Antarctic work; with the sug- 

 gestion that it should be presented to the attention not only of 

 American geologists who undertake southern voyages, but also of 

 the geologists in expeditions sent out by other countries. The 

 problem thus offered for investigation may fairly be regarded 

 as one that has far-reaching results; for if it should appear that the 

 earth's polar climates have really been prevailingly mild, we should 

 have to frame new conceptions of terrestrial physics. 



Cambridge, Mass., 

 April, 1910. 



