PREFACE. 
Yll 
It may, perhaps, be expected that I should have said something 
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 Hymenophyllum 
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 anastomozing ; 
Mr. Presl as distinct and unattached at their extremities. Mr. Smith, 
Curator of Kew Gardens, and who has paid much attention to the 
subject, says, that neither of my figures, and 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 satis- 
faction, and that is the case generally with the coriaceous Ferns, 
particularly after having been dried for the herbarium. 
In order that the future botanist may know the plants from which 
this little work has been written, I intend, (simultaneous with the 
publication of this edition,) to present my specimens of British Ferns 
to the Linnsean Society, that all may sec them who desire it. 
G. FRANCIS. 
27, Cottage Grove, Mile End, 
June 1st, 1842. 
