4 HISTORY OF BRITISH FERNS. 



-at from forty to fifty, according as some of the more doubt- 

 ful forms are ranked as species or varieties. In a botanical 

 point of view the lowest estimate is probably the most cor- 

 rect, as the experience we have of some of the so-called 

 species leads to the notion that they are insensibly united 

 by intermediate forms. As, however, affecting their culti- 

 vation, or when the Terns are taken up as a "fancy/* the 

 higher number is too low ; for we hold that in all such 

 cases, if one plant is palpably different from another, it 

 forms a legitimate object for culture or for study as a dis- 

 tinct object, though the differences may be of such a cha- 

 racter as would lead the rigid botanist to brand it as not 

 " specifically distinct." 



There is a good deal of pedantry abroad on this question 

 of the limits of the species of plants, with which, happily, 

 in this popular sketch of the British Perns, we shall have 

 no occasion to intermeddle. 



The literature of the British Ferns is tolerably extensive, 

 viewed in connection with the comparative numerical insig- 

 nificance of the plants themselves, a mere fraction of the 

 three thousand species of Ferns which are known to botanists, 

 and a mere fraction, also, of our indigenous vegetation. 



Passing by the ancient writers, whose works are both 



