part 2] ANNIVERSARY ADDRESS OE THE PRESIDENT. lxvii 



and countries: facts, or what authors are pleased to regard as 

 facts, are accumulated in large quantity, and in these days of 

 scientific activity there is a danger of becoming wholly absorbed 

 in the task of adding to the pile of data, without pausing to con- 

 sider the value of the material as evidence upon which to base 

 ■conclusions of general interest. A student of science cannot go 

 far without allowing some play to the imagination. As 'in 

 historical enquiries', we are told, ' imagination must always supply 

 the cement that binds together the broken fragments of tradition', 

 so it is in enquiries into the events of pre-history. I venture to 

 think that one of the many privileges of a President is that he 

 •may permit himself a reasonable amount of speculation in 

 •endeavouring to present some of the wider aspects of his subject. 



My aim this afternoon is to penetrate into the remote past of 

 the history of plant-life, briefly to examine some of the early 

 records, and to follow the course of evolution up to the threshold 

 of the period at which Palaeozoic vegetation reached its maximum 

 development: All that I can do is critically to examine the avail- 

 .able documents, and to interpret such as are believed to be genuine 

 by means of a few impressionist sketches. 



' Geology by itself has not yet revealed, and is not likely ever 

 to reveal, a portion of the first crust of our globe ' : we may 

 supplement these words of Sir Archibald Geikie with the statement 

 that, search as we may, we shall never discover the truly primitive 

 .ancestors of the organic kingdom. On the other hand, the more 

 we learn of the physical-chemical attributes of living protoplasm, 

 the better equipped shall we be to speculate upon the conditions 

 -under which life began. Where was the first link in the chain of 

 life forged ? Was it on ' the boundless shores of an azoic sea ' — 

 words which recall a striking passage in a sermon by Prof. T. G. 

 Bonney to which I listened nearly forty years ago — on the muddy 

 margin ' of a primeval lagoon ', in the waters of the first world- 

 ocean, or, as was recently suggested, ' on the mountain-tops of the 

 polar regions ' ? 



Existence in water and on land are two verj different aspects of 

 plant-life. A water-plant is surrounded by the raw material of its 

 food, air, and solutions of salts ; it can absorb at any part of its 

 •surface, and has no concern, either with the provision of an elaborate 

 mechanism for the conduction of water from root to tip of stem, 



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