526 THE BOOK OF GARDENING. 



of New Zealand, Australia, and Tasmania, have stems of a com- 

 paratively thick nature, such as those of the deservedly-popular ■ 

 Dicksonia antarctica, of the Silver Tree-Fern, Cyathea deal- 



bata, C. medullaris 

 (Fig. 331), and a few- 

 others. 



It is worthy of 

 notice that the power 

 of producing crested, 

 depauperated, and 

 other characters 

 peculiar to forms of 

 original species, 

 either of a deciduous 

 or of an evergreen 

 nature, is much more 

 developed among 

 Ferns. growing spon- 

 taneously in England 

 than among those 

 found in any other 

 country, as it is a 

 fact that scarcely a 

 single species of 

 Fern native of the 

 British Isles has 

 retained its normal 

 characters through- 

 out : all have be- 

 come more or less 

 addicted to varia- 

 tions. That power 

 of producing variable 

 forms, either due to 

 the influence of the 

 atmosphere or to 

 other causes, can hardly be ascribed to the effects of cultivation, 

 as most of the crested, undulated, multifid, and other forms of 

 Lastrea Filix-mas, Athyrium Filix-fxmina, Polypodium vulgare, 

 Polystichum angulare, and Scolopendrium vulgare have usually 

 been met with in a wild state in some part or other of the 

 United Kingdom. Even the production of the crested forms 

 of exotic species, such as Adiantums, Gymnogrammes, and 

 Pteris may be said to be a monopoly of this country. 



Variety in Ferns from a Decorative Point of View. — 

 Like any other order of plants Ferns have their pigmies as well as 

 their giants, but the differences as regards dimensions are much 

 more marked in them than in most if not in all others. While 



Fig. 331. — Cyathea medullaris. 



