42 



the same pair is always larger than the upper corresponding one, 

 and more divided ; the disproportion gradually decreasing in each 

 of the following, until toward the apex of the pinna the opposite 

 pinnules are nearly equal : the upper pinnse show very little ten- 

 dency to this irregularity. The venation does not present any 

 striking peculiarities ; the lateral veins are alternate, and generally 

 terminate in the sinus between two serratures, thus determining 

 the arrangement of the fructification. The sori, generally nume- 

 rous, are small, nearly circular, and very prominent in maturity. 

 The indusium accords in position and attachment with that of other 

 species of the genus ; but, unless examined previous to or imme- 

 diately after dehiscence, its presence will often not be recognized, 

 so that the species might be regarded as a Polypodium, with certain 

 members of which genus its habit and the form of its fronds so 

 nearly associate. 



Not having yet had living specimens of this fern in my pos- 

 session, I cannot offer any remarks upon its cultivation, resulting 

 from my own experience. From the little I have seen of it in the 

 keeping of others, and the complaints made respecting its liability 

 to " damp off," it seems to me probable that a treatment similar 

 to that recommended for Polypodium calcareum would be likely to 

 succeed ; not indeed exposure to the sun, which all ferns are better 

 without, and especially those of alpine localities, but fresh air and 

 free drainage. In regard to the supply of water, there is less 

 danger in comparative drought than in superabundance. See the 

 remarks on Polystichum Lonchitis, p. 31. 



Our figure is from a specimen kindly forwarded by Mr. Borrer, 

 gathered by himself in Corrach Dh'Oufillach. 



Genus 6. ATHYRIUM. 



GEN. CHAR. Sori oblong-reniform or crescent-shaped. Indusium 

 attached along the upper side of the lateral veins, opening 

 towards the mid-vein, with a free margin fringed with capillary 

 segments, at length reflexed. 



This genus is adopted, rather to avoid the misplacement of one 

 of the most common and at the same time most elegant of British 

 Ferns, than under the idea of its distinctive character being other 

 than very equivocal. A. Filix-fcemina, the Lady-Fern, differs so 

 greatly in habit from all the indigenous species of the next 

 genus, Asplenium, to which in point of fructification it approaches 

 the nearest, that few amateur collectors would think of seeking 

 among them for its description : I have therefore followed the 

 example of most of my contemporaries, in regarding it as the type 

 of the present. 



