CONTENTS 



Oriqinal Papers 



Physics. — The emissivity of metals and oxides. IV. Iron oxide. George 

 K. Burgess and Paul D. Footb 377 



Physical Chemistry. — A study of the quality of platinum ware. George 

 K. Burgess and P. D. Sale 378 



Geology. — ^The Paleozoic section of the Ray quadrangle, Arizona. F. L. 

 Ransome 380 



Mineralogy. — Nephelite crystals from Monte Ferru, Sardinia. H. S. Wash- 

 ington and H. E. Merwin 389 



Botany. — ^The North American tribes and genera of Amaranthaceae. 

 Paul C. Standlet 391 



Economics. — ^EflSciency as a factor in organic evolution. II. Alfred J. 

 LoTKA 397 



References 



Zoology 404 



Entomology 405 



Proceedings 



The Geological Society 406 



The Biological Society 409 



