K.— BOTANY. 215 



in the succession and nature of the stratified rocks and in the fossil contents, 

 as Mr. Du Toit has obtained from a comparative study of the rocks of 

 South America and South Africa, or as Mr. Harris is finding in his com- 

 parison of the Greenland and Swedish Rhsetic Strata, is arresting enough 

 to make us pause before abandoning the principle of continental drift. 



PAL.a;OBOTANY AS A KeY TO THE PRESENT DISTRIBUTION OF PlANTS. 



If time allowed it would be tempting to deal with still another aspect 

 of Palseobotany ; the importance of a critical study of the floras which 

 immediately preceded the Pleistocene Ice Age. Progress made in recent 

 years in the improvement of methods of deciphering the relics of plants of 

 other days increases the confidence with which it is possible to recbmmend, 

 as a promising field of work, the investigation of Tertiary Floras. There are 

 few more fascinating lines of research than those leading to a fuller know- 

 ledge of the wanderings of plants over the earth's surface. It is only by 

 following the varying fortunes of genera and species during the successive 

 stages of the Tertiary period that we can hope to understand or to explain 

 the present distribution of plants. Let me give one illustration : the 

 work of Mrs. Clement Reid and Miss Chandler, as well as the results ob- 

 tained by many other palseobotanists, has brought into relief the destruc- 

 tive effects of the conditions which culminated in the last Glacial period. 

 We know that the floristic characters now distinguishing European Floras 

 from those of North America and China are in no small degree the direct 

 consequence of the Ice Age : this caused the elimination from the European 

 area of many plants which, had they survived, would give a greater uni- 

 formity to the vegetation of the northern hemisphere than there is at 

 present. In North America and in Asia the way was open ; the northern 

 species were able to migrate far to the South and thus escaped the fate of 

 their companions which were unable to cross the barrier of the Alps and 

 the Mediterranean Sea. 



The Tertiary Floras were more uniform than the floras of to-day. 

 We cannot understand the present distribution of human races if we 

 confine attention to the present, nor can we appreciate the significance of 

 the geographical distribution of floras and their composition unless we 

 consult the herbaria of the rocks. 



Conclusion. 



These are but a few of the promising fields of work open to students of 

 ancient floras. I do not wish to be thought an advocate of extreme 

 specialisation ; my desire is to see a wider recognition on the part of geolo- 

 gists and botanists, whether professionals or amateurs, of the value of 

 palseobotanical studies in relation to problems of general interest. The 

 layman is often deterred from serious application to any branch of science 

 by the length of the road he thinks it will be necessary to travel before 

 becoming qualified for research. If it were essential to master a subject 

 before attempting to contribute to its advancement by original work, 

 none of us could hope to become more than industrious seekers after 

 omniscience within a restricted field. Anyone of average intelligence, 

 provided he or she has the driving force born of enthusiasm and the 



