May 1902.] BOTANICAL SOCIETV OF EDINBURGH 



O 'I ^ 



and other changes ; and who have gradually been ex- 

 patriated, have dwelt for many generations amongst 

 strangers in far-off lands, and who have left descendants 

 which have, in their turn, slowly made their way back to 

 the land whence the exodus took place, and then have 

 gradually retaken possession of the ancestral home. 



With much of the history thus briefly outlined it is, of 

 course, the special province of the geologist to deal. The 

 question before him, in dealing with such matter, is not 

 What is it ? but What ^oas it ? And in searching for 

 answers to that ever-recurring question he often obtains 

 information which proves of interest to his fellow-workers ; 

 and in passing it on to his botanical friends he is enabled, 

 to some extent, to repay many obligations under which the 

 help he has got from them has placed him. 



It may, perhaps, cause many botanists some little sur- 

 prise to find that geologists take any interest in biological 

 matters, seeing that it has so long been the fashion, in 

 Edinburgh in particular, for geologists to confine their 

 attention to the lifeless side of geology, and to take far 

 more interest in making out the points of difference 

 between two bits of stone than in deciphering the history 

 of the forms of life which peopled the earth at the time 

 when those stones originated. Tastes differ. My own 

 lead me to regard all geological matters as subordinate to 

 those relating to the Life of the Past. And I am 

 disposed to attach very much greater importance to 

 questions such as those specially under consideration in 

 this paper than to such trivial questions as the difference 

 between a dolerite and a diabase, or that between a basalt 

 and a melaphyre, and so on, 



One of the many difficulties that beset a geologist in 

 search of evidence of the kind under consideration is the 

 extremely imperfect nature of the Geological Eecord. 

 There is only a very small area in the Briiish Isles where 

 we may look, with any reasonable hope of success, for the 

 kind of information we want. In that area. East AngJia, 

 the records are to be obtained only along a narrow strip of 

 seacoast ; and, even there, they may be said to be confined 

 to the outcrop of strata which, in the aguiegate, are only 

 a few feet in thickness. In these, again, the evidence 



