BRITISH FERNS. 23 



In Ireland this species is much more subject to vary than in 

 England, and I gathered a number of fronds in various parts of 

 the county Kerry, which bear some slight resemblance to Mr. 

 Mackay's beautiful variety ; in those districts the frond is also 

 much larger and wider, and grows with greater luxuriance. In 

 England this fern has insinuated itself into the mortar of our 

 walls, houses, churches, bridges, &c., and into our hedge-rows, 

 and has become in a manner a domesticated plant, and does not 

 enjoy so perfect a freedom as amid the humid, rocky, and shady 

 dingles of Kerry and Wicklow. 



The Common Polypody is somewhat parasitic, preferring 

 the stem of a tree, or the half decayed stump of hazel and 

 white-thorn bushes : over these its creeping rhizoma delights to 

 wander. In the south-west of England it ascends the loftiest 

 trees, and in Epping Forest I have often seen it ornamenting, 

 with its bright green fronds, the heads of the pollard horn- 

 beams, when the wintry blast has stripped them of their 

 summer verdure. 



