SECTION B PLANT MORPHOLOGY 



(Hall 2, September 22, 10 a. TO.) 



CHAIRMAN: PROFESSOR WILLIAM TRELEASE, Washington University, St. Louis. 

 SPEAKERS: PROFESSOR FREDERICK O. BOWER, University of Glasgow. 



PROFESSOR KARL F. GOEBEL, University of Munich. 

 SECRETARY: PROFESSOR F. E. LLOYD, Columbia University. 



BY FREDERICK ORPEN BOWER 



[Frederick Orpen Bower, Regius Professor of Botany, University of Glasgow, 

 Scotland, b. November 4, 1855, Ripon, Yorkshire. Sc.D. Cambridge, England. 

 Assistant to Professor of Botany, University College, London, 1879-82; Lec- 

 turer on Botany, Royal College of Science, South Kensington, 1882-85; Fellow, 

 Royal Society of London; Fellow, Royal Society of Edinburgh; Fellow, Lin- 

 nean Society of London; Corresponding Member of Deutsche Botanische 

 Gesellschaft.] 



THOSE who organized these congresses left to the guests whom 

 they honored with their invitation a high degree of freedom in the 

 handling of their subject. In the exercise of that freedom, which 

 I gratefully acknowledge, I have decided not to attempt any general 

 dissertation on the present position of plant morphology as a whole, 

 but to discuss certain topics only in the morphology of plants, which 

 at present take a prominent place in that branch of the science of 

 botany. These centre round the question of the relation of the axis 

 to the leaf in vascular plants. 



The progress of plant morphology has shown certain well-marked 

 phases in its history, and we stand at the moment on the threshold 

 of a new one. First came the mere description and delineation of 

 the mature form, with special reference to the higher flowering 

 plants. This period included the work of the herbalists, and early 

 systematists, and led to classification as its chief end: but it was 

 enlivened by occasional generalizations, such as that of Wolff, who 

 regarded all appendages of the axis as leaves. It was deeply in- 

 fluenced later by the poetic gloss cast over it by Goethe, in his ideal- 

 istic doctrine of metamorphosis. But this, and the development 

 of the spiral theory, led the stream of botanical thought temporarily 

 away from fact into a region of surmisings. 



From these it was strongly recalled by the initiation of the second 

 phase, about the middle of the last century, the basis of which was 

 the dictum, formulated by Schleiden, that "the history of develop- 



