EBRNS OP GREAT BEITAIN. 65 



In the next pair of branches the lower pinnules are 

 similar to the secondary pinnules of the lower branches, 

 and after that the parts gradually lessen towards the 

 upper portion of the frond. 



The mid-vein of the pinnules is somewhat winding, 

 giving out alternately lateral veins, each of which ends 

 in the part of the margin between two notches ; at the 

 back of each side vein is placed the roundish capsule 

 cluster, covered by the concave indusium with its jagged 

 edge. The clusters of fructification are very numerous 

 and distinct. 



This Bladder-fern is a common plant on many rough 

 and stony grounds of other countries, its geographical 

 range being extensive. It was found on Ben Lawers, in 

 1836, by Mr. Wilson, when with Sir W. J. Hooker and 

 Professor Graham he visited that spot, and it has since 

 been found in several places on the mountains of Perth- 

 shire and Forfarshire, but nowhere in great abundance. 

 It is by some writers termed Polypodium montdnum, 

 Aspidium montdnum, or Cyathea montdna. 



4. C. alpina (Alpine Bladder-fern, or Laciniated 

 Bladder-fern). — Fronds lanceolate, twice pinnate; pin- 

 nules deeply pinnatifid, partly cloven, and slightly 

 toothed at the end. This plant, which is a doubtful 

 native, is the loveliest of this exquisitely beautiful genus. 

 It formerly grew in abundance on an old wall at Low 

 Layton, in Essex, whence however it is almost if not quite 

 exterminated, as the wall was some years ago repaired, 

 though a few specimens of the plant have since been found 

 near the old spot. Sir Wm. Hooker and Dr. Arnott, 

 who examined specimens of the Layton Pern, pronounce 



K 



