VARIATION OF FORM. 371 



into masses. What is the mode of origination of 

 these farinose granules, or what the functions they 

 perform in the economy of those species which possess 

 them, if they have any beyond mere ornament, has 

 not, so far as I know, been determined. 



Much more that is curious and interesting might 

 be noted in the history of these graceful plants ; but 

 the limits of my space compel me to mention but one 

 point more, the phenomenon of variation. That 

 ferns are more liable to what is technically called 

 " sporting," than other plants, is shown by the great 

 numbers of diversities from the normal condition which 

 are already registered. Thus, in the Catalogue of 

 the eminent fern-growers, Stansfield & Son, with its 

 Supplement, we have the named and described varie- 

 ties of a few well-known native species advertised to 

 the following extent: Athyrium filix foemina, 56 

 forms ; Asplenium adiantum-nigrum, 29 ; Bleclmum 

 spicant, 53; Lastrea filix-mas, 34; Polysticlium an- 

 gulare, 43 ; Scolopendrium vulgare, 90 : making, 

 out of these six familiar species, three hundred and 

 five named varieties offered for sale by one firm. The 

 possession of well-marked varieties is quite as highly 

 valued by most amateurs, as that of distinct species ; 

 hence, there is a constant stimulus to the search for 

 new divergencies ; while the discovery that monstro- 

 sities once found are not only in general constant, but 

 have a strong tendency to perpetuate themselves by 

 spores, and even to originate new and stranger forms, 

 is rapidly augmenting the stock. Mr Bridgman, in 



