The Present Position of Palaeozoic Botany. 



D. H. Scott, F. R. S., 



Lately Honorary Keeper of the Jodrell Laboratory. Royal Botanic Gardens, Kew. 



lutrodiictiou. 



The object of the present article is to give a sketch of our 

 knowledge of Palaeozoic plants and their affinities, as affected by 

 recent discoveries. There is probablj' no branch of Botany which 

 has made more rapid advances of late years than the study of fossil 

 plants, and it is especially the investigation of the more ancient floras 

 which is now leading- to new results of far-reaching significance. 

 Under these circumstances it may be of service to take a general 

 survey of the position, and I have gladly responded to the request 

 of the Editor that I should contribute an article on this subject. 



Since the publication of the "Origin of Species" and the consequent 

 general acceptance of the doctrine of Evolution, the determination 

 of the course of descent has become the ultimate object of the scien- 

 tific systematist; the problem is an historical one and the most 

 authentic documents available are the remains of the ancient or- 

 ganisms preserved in the rocks. Remote and even unattainable as a 

 full solution of the problem must be, we may confidently hope, in 

 tracing something of the past history of plants, to throw new light 

 on their relationships. 



Before proceeding to discuss the results of recent research it 

 will be well to consider shortly the form in which the evidence is 

 presented to us. The various modes of preservation of fossil plant- 

 remains may be grouped under two main heads, which have been 

 distinguished as Incrustation and Petrifaction. Under the former are 

 included all casts, moulds and impressions which exhibit the super- 



