PREFACE. 
Vll 
relative to the new system of classifying Ferns according to their 
venation. I have not done so in the body of the work, because I do 
not find the system either correct, convenient, or practicable. For 
example, the veins of the British Trichomanes and Hymenopliyllum 
are precisely similar, yet few would assign all these to the same 
genus. The veins of Polypodium vulgare and Phegopteris are very 
different from each other, yet the plants are conveniently placed 
together. The veins of the latter plant resemble those of Aspidium 
Oreopteris, yet I cannot consent to unite the two into one species. 
As to the veins of Grammitis Ceterach, Mr. Newman shows them 
as anastomosing ; Mr. Presl as distinct and unattached at their 
extremities. Mr. Smith, Curator of Kew Gardens, who has paid 
much attention to the subject, says, “ that neither of my figures, 
(which are copied, the one from Newman, the other from Presl,) 
is correct.” And as to my own opinion, I confess I cannot make 
them out at all to my satisfaction, and that is the case generally 
with the coriaceous Ferns, particularly after having been dried for 
the herbarium. 
June 1st, 1842 . 
A Third Edition of this work being now called for, I am sorry that 
I have it not in my power to offer any additional remarks upon the 
plants described. I would not have it inferred, however, that I 
consider my book either without error or complete, but merely that 
having been, since the issue of the second edition, resident on the 
Continent, and at all times much occupied, I have made no additions 
to my own stock of Fern knowledge ; and moreover I never expected 
that a third edition would be called for, and therefore made no 
preparation for it. 
I have to remark, however, that I have been blamed by one or 
two botanists for not discarding some of the present names, and 
adopting the more ancient, Lastreea, and other. I desire to pay the 
greatest deference to the opinions of others, and am most happy to 
learn from all, as to matters of fact, at all times ; yet a change of 
names is always perplexing, and in this case unnecessary. I cannot 
