62 BRITISH FERNS, 
stones, especially soft sand-stones, and fill up the 
interstices with a mixture of leaf-mould and sand: it 
cannot be too freely exposed to the weather, except in 
London, where the smoky atmosphere appears very 
distasteful. 
7. BEECH FERN. Puecorrenis. 
Polypodium Phegopteris, Linneus. B. F. 49. 
- The caudex of the Beech Fern is stolon-like, wiry, - 
tough and creeping; the fronds are thrown up in 
May, rising on erect, succulent and very brittle stems, 
clothed with a few pale scattered seales; they unfold 
sessile and united to the main stalk by the midrib 
only; the remaining pinnz point forwards, they are 
