CONTENTS 

 Original Papers 



Page 



Physics. — "Physical" vs. "chemical" forces. P. V. WELLS 361 



Botany. — Notes on the genus Dahlia, with descriptions of two new species 



from Guatemala. W. E. Safford. . . ■ 364 



Abstracts 



Biology 374 



Geography 375 



Mycology 37^ 



Phytochemistry 379 



Spectrophotometry ; 380 



Technology 381 



Proceedings 



Geological Societj'^ of Washington . 382 



Scientific Notes and News 388 



