PREFACE. 
viii 
true botanist can wait for more exact and comprehensive ac¬ 
quaintance with characters which do, and do not, distinguish 
species: and when, by experience, he is able to determine such 
marks, imaginary species fall back into the rank of varieties; 
or he is able, with* the confidence of accurate observation, to 
pronounce that a true species, which by others may have been 
incorrectly regarded as a variety of some other form. 
The species recently observed in Derbyshire are twenty- 
three, all of which are figured in this volume: there are a 
few species and genera, which might have been looked for, 
especially in the more elevated parts of the county, and 
which may even yet reward the exact scrutiny of perse¬ 
vering search. Such are Hymenophyllum — the H. Ton- 
bridgenss* (fig. 1) and H. Wil- 
soni f — our Filmy Ferns , which 
creep over the surfaces of wet 
rocks, and resemble Jungerman- 
nias more than Ferns:— Crypto- 
gramma crispa , and Asplenium 
septentrionale , alternifolium , and 
lanceolatum; Polypodium The- 
lypteris also, and Lastrea rigida , 
may have escaped observation. J 
But it is more probable that 
the inroads of improvement in 
* “ On the hills, from Macclesfield to Buxton, on mossy rocks.” Mr. Bradbury, 
in Botanist's Guide. 
f H. Wilsoni is in Dr. Garner’s List of Staffordshire Plants, as occurring at 
Gradbich, near Flash, within a few miles of Buxton. 
J Chinley Hills, near Chapel-en-le-Frith, are given in the <e Botanical Guide,” as a 
locality of Cryptogramma crispa. The plant occurs in similar situations in Cheshire 
and Lancashire. Its English name, “ Parsley Fern,” correctly describes the appear¬ 
ance of this species. 
