BRITISH FERNS. 3 



treated the subject, that when the result of his labours is pub- 

 lished, it will abundantly repay the botanist for a careful and 

 minute examination. Mr. Smith having, in the most unreserved 

 manner, communicated to me his own ideas on the subject of 

 arrangement and nomenclature, I was delighted to find, that, 

 vdth very few exceptions, our views were similar : in one or two 

 instances I was obviously wrong, and in these instances I was too 

 glad to have the opportunity of rectifying my errors by the aid 

 of his superior knowledge of exotic genera. In a few instances 

 we still differ, and in announcing this, I fear I shall be considered 

 as pronouncing my own condemnation : still I venture to pursue 

 my way, and "by an earlier appearance in the literary horizon, 

 give myself the chance of what the astronomers call an Heliacal 

 risirig, before the luminary in whose light I am to be lost shall 

 appear." 



In making out my list of genera I have followed no other rule 

 than that of priority ; and if, in any instance, I have departed 

 from this rule, the departure has been entirely unintentional, 

 and I shall be glad to be informed, in order that I may take an 

 early opportunity of correcting my error. The characters which 

 I have assigned the genera are very concise, perhaps it may be 

 thought too much so, but it has been my wish not to swell the 

 technical portion of a work which is avowedly intended less for 

 the scientific botanist than for the general reader; moreover, a 

 repetition of the generic characters will occur in the description 

 of each species. 



With respect to numerous species here treated as varieties, I 

 have not intentionally omitted one of the characters by which 

 they may be distinguished, nor have I degraded them from their 

 former station in order to save the trouble and expense 

 of figuring them. I have taken as much pains to be explicit in 

 these varieties as I should have done were they still treated as 

 species, and each is as correctly figured : the reader must judge 

 whether they are to be considered species or varieties. It will 

 give me infinite pleasure to know that permanent and distinctive 

 characters have been found for Polypodium calcareum, Woodsia 

 hyperborea, Cystopteris dentata, Polystichum Lonchitis, Lastraea 

 dumetorum, Athyrium rhaeticum, and Asplenium alternifolium : 

 these would make a noble addition to a list which is at 

 present a very meagre one ; but until such characters are found 

 I consider it far better to leave them as I have left them, in the 



