70 HISTORY OF BRITISH FERNS. 



fern ; while in others, they last but from spring to autumn 

 in each succeeding year. 



The Polypodies derive their common name from Poly- 

 podium, which literally means, many-footed, and has been 

 explained to apply to the branching of their creeping 

 stems, the protuberances on which, in the earlier stages 

 of development, have some supposed resemblance to the 

 Polypes. 



Polypodimn vulgare, Linncvus. 

 The Common Pohfpodij. (Plate I. fig. 2.) 



This is an evergreen Fern, growing abundantly on pol- 

 lard trunks, mossy banks, moist rocks and walls, and old 

 thatched roofs ; and pretty generally distributed over the 

 United Kingdom. When sheltered the fronds are of a 

 cheerful but not bright green, and it may be then recog- 

 nized by the comparatively large circular patches of golden 

 orange or brown spore-cases ; indeed, it may generally be 

 known by this feature alone, no other native sort haviuo- 

 the fructification at all similar in appearance. 



This species has a creeping stem or rhizome as thick as 

 one's finger, which is covered over with pale brown chaffy 

 taper-pointed scales. From its upper side spring the 



