44 THE AGE OF THE EARTH 



Note. — At the time when this address was delivered 

 I felt keenly the i^ap left in the argument by the absence 

 of any statement concerning the evolution of land-i)lants. 

 Since 1896 an immense amount of labour has been ex- 

 pended u[)on fossil floras, and startling conclusions as to 

 the affmities of certain groups have been placed on a 

 solid foundation. Now, after the lapse of ten years, it is 

 fiir more possible than it was in 1896 to compare safely 

 the evidence )ielded b) fossil plants with that of fossil 

 animals. Allowing for the important difference in the 

 length of the records — animals a])pearing in full force in 

 the Cambrian, plants only in the Devonian — the two lines 

 of evidence sup[)ort precisely the same conclusion. 



Professor A. C. Seward, E.R.S., in his Presidential 

 Address to Section K (I)Otany) of the meeting of the 

 British Association at Southport. in 1903, took as his 

 subject Floras of the Past : tJicir Composition aiid 

 Distribution. He speaks of the Devonian and Lower 

 Carboniferous plants as * practically the oldest records of 

 l)lant-life ', and states that they ' lead us away from the 

 present along converging lines of evolution to a remote 

 stage in the history of life': the distribution of their fossil 

 remains over the globe * shows how widely some of the 

 })lants had migrated from an unknown centre far back in 

 a still more remote age. We are, as yet, imable to 

 follow these Devonian plants to an earlier stage in their 

 evolution. We are left in amazement at their specialized 

 structure and extended geograj)hical distribution, without 

 the means of perusing the opening chapters of their 

 history '. ' 



During the present year my friend Dr. D. II. Scott, 

 P\R.S., has published a valuable and comprehensive 

 memoir on The Present Position of Palaeozoie Jn4any^- 

 setting forth the results of modern researches u[>on the 

 structure and evolution of fossil plants. 



Dr. Scott has most kindl)- provided me with the fol- 

 lowing concise summary of the history of plaut evolution 

 as set forth in the fossil record at present known to us: — 



' RcJ'orl, 190,:}, j>. S3 1. 



' Pro^rcssus Rci Jjoiatiuac, ]q.u^, 1906, jp. 139-217. 



