266 H. L. FAIRCHILD — GEOLOGY UNDER PLANETESIMAL HYPOTHESIS 



nomenon referred to is the transfer of matter through the action of vol- 

 canoes from below the earth's crust to the earth's surface. The volume 

 of material thus withdrawn from the earth's interior, and consequently 

 necessitating a crumpling of the earth's crust, is measurable in tens of 

 millions of cubic miles (Van Hise), and is probably as important in 

 leading to crustal deformation as any other agency that has been in 

 action. The principle here referred to has been neglected by nearly all 

 students of diastrophism." 



FREDERICK W. SARDESOWS COMMENTS 



The communication by Doctor Sardeson directs attention to his illus- 

 trated article published in the American Geologist, volume 26, page 388, 

 1900, and cited in volume 33, 1904, page 120, which tends to discredit 

 the idea of a heavily carbonated atmosphere in early geologic time. 

 Some fossil corals (Monticuliporoidea) which occur in the Ordovician 

 have their branches twisted in a manner simulating heliotropism, thus 

 indicating direct sunshine and not merely diffused light. 



Doctor Sardeson says : " What is remarkable, further, is that the 

 branches (of Rhinidictya mutabllis Ulr.) twist as they ascend, and turn 

 the faces of the zoarium thus from east to west. This could be explained 

 as due to influence of the sun's rays upon the zooids, those that were in 

 the most favorable position growing a little the faster and crowding their 

 neighbors, and the crowding following the sun's course caused a twist- 

 ing from east to west. A tendency to turn in that direction would be- 

 come finally inherent. This turning might be explained also as a device 

 to prevent the repeatedly dividing branches from interfering ; but it 

 appears to be not defined by that use, since the twisting is least marked 

 where the branching is most frequent, as in the lower older part of the 

 zoarium, and moreover the important fact remains that they twist from 

 left to right." 



