94 TOWN GEOLOGY. [iv. 



and still less in our cultivated fields. But in these 

 islands there are two noble species, at least, which are 

 true swamp-ferns ; the Lastrsea Thelypteris, which of 

 old filled the fens, but is now all but extinct ; and the 

 Osmunda, or King-fern, which, as all know, will grow 

 wherever it is damp enough about the roots. In 

 Hampshire, in Devon, and Cornwall, and in the south- 

 west of Ireland, the King-fern too is a true swamp 

 fern. But in the Tropics I have seen more than once 

 noble tree-ferns growing in wet savannahs at the sea- 

 level, as freely as in the mountain-woods ; ferns with 

 such a stem as some of the coal ferns had, some fifteen 

 feet in height, under which, as one rode on horseback, 

 one saw the blazing blue sky, as through a parasol of 

 delicate lace, as men might have long ages since have 

 seen it, through the plumed fronds of the ferns now 

 buried in the coal, had there only been a man then 

 created to enjoy its beauty. 



Next we find plants called by geologists Calamites. 

 There is no doubt now that they are of the same 

 family as our Equiseta, or horse-tails, a race which has, 

 over most parts of the globe, dwindled down now from 

 twenty or thirty feet in height, as they were in the old 

 coal measures, to paltry little weeds. The tallest 

 Equisetum in England the beautiful E. Telmateia 

 is seldom five feet high. But they, too, are mostly mud 

 and swamp plants; and so may the Calamites have 

 been. 



The Lepidodendrons, again, are without doubt the 

 splendid old representatives of a family now dwindled 

 down to such creeping things as our club-mosses, or 

 Lycopodiums. Now it is a certain fact, which can be 

 proved by the microscope, that a very great part of the 



