AUTHOR'S PREFACE. 



natural or artificial in character ; thou, if in a small area like that of (Jrcat TSritain, so many varieties 

 often marked, nn<l usually constant in diameter occur, the variations must become much mom 

 numerous ami marked, if the species is spread, as often happens, over widely separated and extensive 

 |H>rtions of the globe* It may safely he concluded from this further view of the subject, Ihat an infinity 

 of species, founded on slight diilerences and often on the mere fact of geographical separation, are thus 

 thrown open to doubt, or at once reduced to mere loeal variations. Many apparently genuine species 

 also, thus become broken down and amalgamated by the discovery of connecting varieties, it may be, at 

 their antipodes. The number of apparently good sjHJcics so-called which thus become disturbed by the 

 occurrence of intermediates in distant latitudes, and under varied elimatal conditions, by which means 

 tolerably exact definitions become unattainable ; and the impossibility of believing in such an excessive 

 natural diffusion and variation of specific vegetable typos from any intelligible centre of creation, 

 which in that case would l>c a necessary assumption — and all such conjectures as to origin arc mere 

 assumptions and an affectation of being wise al>ove that which is written, — become a serious obstacle 

 in the way of continuing to hold faith hi the very existence of species, except when viewed in the 

 light already indicated, namely, as artificial collective groitjm of individuals associated for convenience. 

 One object of enumerating the varieties of British Ferns then, has been to prove, that so-called 

 I rrics do vary wry much in our limited area ; :-!«-i hence to draw the inference, sufficiently supported 

 indeed by facts, that they vary much more when a wider range is taken into account ; such a conclusion 

 being clearly unfavourable to the multiplication of species* It is to be remembered that the variations 

 here spoken of, though sometimes slight, are nevertheless often marked, and for the most part constant 

 and appreciable ; by no means frequently ranging as mere monstrosities but even then for the most 

 jiart permanent, and renewable from the spur- - — this latter fact probably allbrding incidental proof that 

 spores themselves are in reality buds, aud uot at all analogous to seeds, and suggesting that the sort 

 may after all have nothing to do with fructification in the usual sense. 



It only remains here to acknowledge the much assistance which has been afibrded us in the 

 progress of our labours; nil of which it is hoped has been duly recorded. Our thanks are however 

 especially due to Sir W. J- Hooker, for the facilities afibrded by ready access to his valuable Herbarium 

 in tracing the geographical range of the species; to Dr. Lindley, for his careful supervision ; and to 

 Mr, G. U, Wollastoii, for his valuable notes on varieties. 



Cieclhu, Jttfy utfi, i$&$. 



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