FLORAS OF THE PAST. 

 WEALDEN. 



BY far the best known of the ancient floras are those 

 of Upper Carboniferous and Lower Permian age. 

 The wealth of material afforded by the sandstones, shales 

 and coal-seams of the Upper Carboniferous system, and 

 more especially by the petrified plant fragments from the 

 calcareous nodules of the Lancashire and Yorkshire coal- 

 fields, and the siliceous nodules of French and German 

 localities, have enabled palaeobotanists to reproduce a fairly 

 complete picture of the vegetation of the Coal period. The 

 excellent state of preservation of many of the older fossil 

 plants has compelled the attention of botanists whose chief 

 concern is with the plants of to-day. In addition to the 

 splendid results obtained from a detailed anatomical inves- 

 tigation into the structure of special types of Coal -Measure 

 and Permian plants, there are other facts of considerable 

 interest to be gained from a general revision of Palaeozoic 

 floras from a phytogeographical point of view. Interesting 

 results have already been obtained in this field of work, 1 

 but a critical comparative study of the component elements 

 of the various Palaeozoic floras should lead to the discovery 

 of valuable evidence bearing on the questions of plant dis- 

 tribution and the existence of botanical provinces towards the 

 close of the Palaeozoic epoch. It is the botany of the oldest 

 and, on the other hand, of the most recent geological periods 

 that has so far received the chief share of attention at the hands 

 of botanists, while the floras of the Mesozoic epoch have not 

 hitherto attracted much notice from others than specialists. 



In the present article it is proposed to attempt a brief 

 summary of the general features of the vegetation of the 

 Wealden period, special reference being made to facts 

 which may prove of interest to botanical readers who are 



1 Zeiller. [Vide also Science Progress (new series), vol. i., No. 2, p.. 

 178, 1897.] 



