TRICHOMANES. 189 



only in high mountain regions, where they grow from the 

 crevices of the moistened rocks. They are both rare, though, 

 from the inaccessible localities in which they only occur, 

 they may really be more abundant than is generally sup- 

 posed. Both also appear to be confined to the northern 

 parts of our hemisphere. 



Their rarity rather than their beauty invests these plants 

 with interest for the cultivator. They re^iuire to be kept 

 in a cold shady frame, to be potted in porous soil amongst 

 lumps of stone, to be carefully guarded against drought or 

 stagnant moisture, and to be rarely disturbed at the root. 



Genus XV. TRICHOMANES, or BRISTLE FERN. 



The Trichomanes is the most tropical genus among our 

 native Ferns ; it is also one of the rarest ; the one indi- 

 genous species being among the few which are met with 

 very sparingly, and within a comparatively narrow range. 

 It is not, however, the rarest of our species, although very 

 unfrequent, and local. Unlike in texture all the other 

 native kinds excepting the Hymenophyllums, being quite 

 pellucid, and of the most delicately-crisped appearance 



