No. 544] BOTANICAL SOCIETY OF AMERICA 239 



II. The Eelations of Paleobotany to Botany 

 3. Ecology 

 DR. ARTHUR HOLLICK 

 New York Botanical Garden 



As I understand the object of a symposium it is not to 

 provide opportunity for the reading of exhaustive or 

 highly technical dissertations, or for the presentation of 

 new material, but rather to present recognized facts as 

 clearly as may be, with recent interpretations of their 

 meaning or significance, in order to enlist interest in and 

 to stimulate discussion of the subject under considera- 

 tion; and this seems to have been the view which was 

 taken by those who have preceded me. In such connec- 

 tion it is my privilege to present the claims of ecology to 

 recognition, in indicating the relations between botany 

 and paleobotany. 



Plant ecology, as the term is commonly denned and 

 understood, is that branch of botany which deals with the 

 study of the interrelations of plants and their relations 

 to environment. As a distinct science it is practically a 

 product of the present generation. I do not know exactly 

 when the term was first employed in scientific literature, 

 but it certainly was not in general use in connection with 

 botany at the time of my earliest contributions to the 

 subject, and I did not then know that I was dealing with 

 ecology when discussing certain floras and their accom- 

 panying geologic and physiographic features of envi- 

 ronment. 



The ecologic relations between botany and paleobotany 

 are mostly concerned with the problems of phytogeog- 

 raphy. Paleobotany has supplied the explanations of 

 numerous puzzling facts in regard to the geographic 

 isolation of certain genera ; the occurrence of some genus 

 or species only in certain widely separated regions of the 

 earth; and the problems in connection with many endemic 

 floras. Indeed the phenomena of plant distribution m 



