90 BRITTLE FERN. 



inquiry — as regards the species of Cystopteris — not only all 

 seedling, immature, barren or monstrous fronds, but also all 

 those which appeared to owe their peculiarities to the varied 

 degrees of drought or moisture, elevation, protection or expo- 

 sure, or the numerous other casualties to which so hardy yet 

 fragile a fern is by its nature subjected ; and to compare those 

 only which, cultivated under corresponding circumstances, had 

 arrived at a corresponding state of maturity. The result of a 

 very careful scrutiny of a number of plants, received through 

 the great kindness and exertion of botanical friends, under the 

 names of fragilis, dentata, angustata, and alpina, is, that I am 

 unable to give my assent to the species described by Sir J. 

 E. Smith, or to propose others for substitution in theii* stead. 

 I find that differences, however striki n g, subside under cul- 

 tivation ; and that almost entire uniformity obtains amongst 

 greenhouse plants, which, when found growing under varied 

 circumstances of soil, aspect and altitude, exliibited great dis- 

 crepancies as to size and subdivision of parts. Under these 

 circumstances, I prefer treating them still as constituent parts 

 of a single species, not even naming as varieties those aber- 

 rations from normal figure which possess no permanency. 



tapljiral imtp. 



This pretty and fragile, but very hardy species, has an ex- 

 tended range in the northern temperate regions, extending to 

 very high latitudes. In Em^ope it occurs in Norway, Lapland, 

 Sweden, Russia, Denmark, Poland, France, Germany, Hun- 

 gary, Portugal, Spain and Italy ; it extends throughout Asiatic 

 Russia into Kamtkatcha, and has been gathered on the shores 

 of Kotzebue Sound and Eschscholtz Bay ; it is frequent in Ca- 

 nada and the Northern States of America ; it is also reported 

 from Northern and Southern Africa, and from the Islands of 

 the Pacific Ocean. 



In Great Britain it also has a wide range. 



Scotland. — Observed more or less abundantly in every county I visited. 



'England. — In the northern counties, Northumberland, Cumberland, 



Durham, Westmoreland, Lancashire and Yorkshire, it is very abundant ; 



so also in Derbyshire and Staffordshire, and, further south, in Gloucester- 



