172 ON THE ORIGIN OF COAL. 



ferns, and other small plants, were attributed to 

 low marshy land. 



No reason was assigned for the rarity of 

 specimens of ferns, showing remains of fructifi- 

 cation, — although it is well known that, in the 

 oolitic Coal-field, such plants are frequently met 

 with in that state, — except that the floods swept 

 down the plants at a period of the year when 

 their fructifications were absent. The long pro- 

 cesses radiating in quincuncial order from the 

 Stigmaria, to a considerable distance, did not 

 allow of its being so easily drifted, therefore it 

 was allowed to have grown in the position where 

 it is found, and called an aquatic plant. As it 

 was always met with in the Coal floors, it was 

 supposed to have been a kind of harbinger of 

 dry land, filling up, by its rapid growth, the 

 swamps, until a bed of soil was formed for the 

 growth of the larger trees, like the Sigillaria, &c. 

 This view was taken by many authors, who 

 represented the vegetable matter, now forming 

 coal, to have grown on the spots where it is now 

 found on dry land. The parties who advocated 

 the drift hypothesis, carried by currents of water 

 the Stigmaria with all the rest of the plants into 

 their Mare Carhoniferum^ where they formed 



