ASPLENIUM MARINUM. 241 



The radicles of Asplenium marinum are black, wiry, tough, 

 long, and so firmly fixed in the crevices of rock, that it can- 

 not be eradicated without considerable trouble : the caudex is 

 tufted, black, and its crown covered with bristly scales : the 

 fronds make their appearance in June and July, ripen their 

 seed in October and November, and remain perfectly green 

 throughout the year ; in August, the fronds of two seasons are 

 equally vigorous, the younger ones being distinguished by their 

 paler colour and immature fructification. The stipes is gene- 

 rally scarcely a third as long as the frond : the frond is linear 

 and simply pinnate : the pinnae are attached by a narrow base, 

 their forms are various, as will be seen by the figures ; two larger 

 than the rest frequently appear near the apex : the pinn® are 

 connected by a narrow wing running along the rachis, as shown 

 at d, page 239. The lateral veins are forked almost immedi- 

 ately after leaving the midvein; the anterior branch bears a 

 long linear cluster of bright rust-coloured capsules ; this, when 

 young, is covered by a white membranous involucre, of similar 

 form, which always opens towards the apex of the frond. 



Wmtm. 



The two forms already spoken of are so intimately connected 

 by a series of intermediate states, that it would be confusing to 

 the inquirer were I to attempt to describe or distinguish them. 



€nlhtt 



This is a most difiicult fern to deal with in cultivation, un- 

 less carefully protected from exposure : it will thrive luxuri- 

 antly in a stove-house, with a moist heat of 70° Fahr., but dies 

 on rock-work, even in the purest air, if denied the advantage of 

 the sea-breeze ; this is the more remarkable, since at Newton, 

 Warrington, and Killarney, as recorded in the preceding pages, 

 it has voluntarily forsaken the vicinity of the sea. 



