INTRODUCTION. IX 



paid some attention to the specific characters, as laid 

 down by our best Authors, and I am inclined to 

 doubt whether those most distinctive have been 

 employed. It appears that the manner in which 

 a frond is cut or divided, constitutes almost the sole 

 ground of specific distinction. Now, we find a great 

 number of specimens in a state of semi-cultivation, 

 i. e. partaking more or less of the influence of the 

 spade, or plough and harrow, and nourished by an al- 

 most infinite variety of soils and manures ; and we also 

 find amongst such specimens as great a variety of cut- 

 ting, as we do in the colours of domesticated animals. 

 I think no botanist, who allows his memory to turn to 

 the varieties he has observed of Lastraea dilatata and 

 Polystichum aculeatum, will for a moment deny this; 

 and yet what botanist has ever presumed to treat of 

 the cutting of the frond in Ferns as of any other 

 than the highest importance ? I entertain a different 

 opinion. I think that mere cutting of frond is of no 

 more value than colour in fowls or cows, and there- 

 fore should not be used as the leading character 

 of a species ; to distinguish which, I would look for 

 less fickle characters in the figure, position, and 

 covering of the masses of seed, in the habit of the 

 rhizoma, and in the general outline of the frond. 



During the summers of 1837-8-9, having many 

 opportunities of obtaining roots of Ferns, I planted 

 them with care, for the purpose of obtaining a more 

 correct knowledge of the variations to which they 

 were subject ; and as I have heard a great deal of 



b 



