part 2] ANNIVERSARY ADDRESS OF THE PRESIDENT. lxxxvii 



Highlands of Scotland with the Scandinavian peninsula, and con- 

 tinued across the north of Greenland to the arctic lands of North 

 America. The uplifting of previously submerged portions of the 

 earth's crust was the first stage in the change from marine to 

 continental conditions ; it is not unreasonable to offer the opinion 

 that it was on these upraised sea-floors that the successful migrants 

 from the ocean entered upon the task of colonizing the land. 



The records of Devonian vegetation are often in the form of 

 impressions preserved in sediments deposited some distance from 

 the place where the plants grew. In some localities the presence of 

 roots penetrating the rocks, or the occurrence of stumps of trees 

 with their slender root-like appendages still radiating through the 

 soil, indicates the preservation of vegetation in its original position. 



The Essay on Devonian Floras, published after his death, was 

 one of the last of Arber's contributions to the science to which he 

 devoted himself Avith unflagging zeal and with admirable singleness 

 of purpose. His view was that the older Devonian plants, on the 

 whole, are relics of an extinct group of Thallophyta, exhibiting in 

 their morphological features indications of a transition to the 

 Vascular Cryptogams. Whether one agrees or not with the main 

 contention developed in Arber's treatise — and I cannot but think 

 that, if the author had lived to read the later papers by Kidston & 

 Lang on the Rhynie plants, he would have modified some of the 

 views that he had propounded — one recognizes that it is an able 

 and stimulating addition to palseobotanical speculation, and, in- 

 cidentally, a very useful compendium of facts. It must, however, 

 be said that the section of the work dealing with the geological 

 age of the Scottish plants needs considerable revision and 

 correction. 



In a paper published in 1889 on some Devonian plants from 

 Ohio, J. S. Newberry said : 



' While they have given us fascinating glimpses of the head of the column of 

 terrestrial vegetation that has marched across the Earth's stage during the 

 different geological ages, they have given us little insight into the spirit of 

 the movement.' 



Since this was written many additional facts have been recorded, 

 the remains of older Devonian floras then unknown have been 

 described, and the discovery of the Rhynie chert-bed has enabled 

 us, not only to acquire an exact anatomical knowledge of certain 



