TABLE OF CONTENTS 



VOLUME IX 



BIOLOGY 



Development of Morphological Conceptions .... 

 BY PROF. JOHN MERLE COULTER, PH.D. 



The Recent Development of Biology ..... 

 BY PROP. JACQUES LOEB 



PHYLOGENY. 



A Comparison between Artificial and Natural Selection 

 BY PROF. HUGO DE VRIES, Sc.D., LL.D. 



The Problem of the Origin of Species ..... 

 BY PROF. CHARLES OTIS WHITMAN, PH.D., LL.D. 



PLANT MORPHOLOGY. 



Plant Morphology .......... 61 



BY PROF. FREDERICK ORPEN BOWER, Sc.D. 



The Fundamental Problems of Present-Day Plant Morphology . . 81 

 BY PROF. KARL F. GOEBEL, Sc.D. 



PLANT PHYSIOLOGY. 



The Development of Plant Physiology under the Influence of the Other 



Sciences ........... 103 



BY PROF. JULIUS WIESNER, PH.D., J.U.D. 



Plant Physiology Present Problems ...... 125 



BY PROF. BENJAMIN MINGE DUGGAR, B.S., PH.D. 



PLANT PATHOLOGY. 



The History and Scope of Plant Pathology ..... 149 

 BY PROF. JOSEPH CHARLES ARTHUR, Sc.D. 



Vegetable Pathology an Economic Science ..... 165 

 BY MERTON BENWAY WAITE, B.S. 



ECOLOGY. 



The Position of Ecology in Modern Science ..... 17? 

 BY PROF. OSCAR DRUDE, PH.D. 



The Problems of Ecology ........ 191 



BY PROF. BENJAMIN LINCOLN KOBINSON, PH.D. 



