PALEOBOTANY AND EVOLUTION. 



THE geological history of existing- classes of plants is 

 still very imperfectly known. The records of the 

 vegetation of past ages are from the nature of the case 

 exceedingly scanty, and it is only under special conditions 

 that it has been possible for plant remains to leave traces of 

 their existence in the stratified deposits of the earth's crust. 

 The much sreater abundance of fossil animals, and the 

 better state of preservation of their hard calcareous, 

 silicious, and bony skeletons, have enabled palaeontologists 

 to furnish valuable aids to the history of evolution. Some 

 of these contributions from their readily perceived im- 

 portance and exceptional interest, have long been familiar 

 to every one possessing the most superficial knowledge of 

 Natural Science. 



From palaeobotanists we have had various attempts to 

 illustrate the progress of plant evolution by means of 

 genealogical trees of the most comprehensive form, starting 

 from a host of supposed algal remains in the older Palaeozoic 

 sediments, and culminating through various ramifications 

 in the highest types of plant structure. The data on which 

 it has thus been essayed to illustrate the manner of origin 

 of existing classes of plants, are frequently valueless, and 

 the evidence available hopelessly inadequate for so am- 

 bitious an object. In the majority of cases the building 

 up of such imaginary lines of development has tended " to 

 confuse fancy with fact, and to create mere confusion ".^ 

 The acknowledged insufifiiciency and unscientific foundations 

 of speculations on plant evolution, have tended to an 

 attitude on the part of scientific investigators of extreme 

 scepticism, and to a general mistrust of palseobotany as a 

 factor of primary importance in phylogenetic inquiries. 



Although, generally speaking, fossil plants are com- 

 paratively rarely found in a condition sufficiently satisfactory 



^ Huxley, Method and Results, London, p. 120, 1893. 



