PROCEEDINGS 



OF THE 



American Philosophical Society 



HELD AT PHILADELPHIA 



FOR PROMOTING USEFUL KNOWLEDGE 



Vol. LIV. September, 1915. No. 219. 



CONTENTS 



Symposium on -the Earth: Its Figure, Dimensions and the Constitu- 

 tion of its Interior: 



I. The Interior of the Earth from the Viewpoint of Geology. 



By T. C. Chamberlin ....-.._ 279 



II. Constitution of the Interior of the Earth as Indicated by Seis- 



• mological Investigations. By Harry Fielding Reid - - 290 



III. The Earth from the Geophysical Standpoint. By John F. 



, Hayford ._-- 298 



Morphology and Development of Agaricus rodmani. By Geo. F. 

 Atkinson __.-... 309 



The Euler-Laplace Theorem on the Decrease of the Eccentricity of 

 the Orbits of the Heavenly Bodies under the Secular Action of a 

 Resisting Medium. By T. J. J. See ---- 344 



PHILADELPHIA 



THE AMERICAN PHILOSOPHICAL SOCIETY 



104 South Fifth Street 



1915 



