524 THE BOOK OF GARDENING. 



elegance, and diversity of form are concerned, no equal in any 

 other portion of the Vegetable Kingdom. 



One of the most striking points in connection with the history 

 and the existence of Ferns all over the Globe, and one which, 

 in artificial cultivation, deserves to be taken in consideration, is the 

 extremely wide range of their geographical distribution. We know 

 of no other order of plants the representatives of which are found 

 in such varied positions and dissimilar aspects, or which show 

 such different habits of growth. From the Tropics, where they 

 exist in profusion, to the Arctic regions, as far north as Greenland, 

 Ferns are found in greater or less quantities, some at an altitude 

 varying from 10,000ft. to 12,000ft., and others at the sea-level, 

 which knowledge actually indicates that in artificial culture while 

 certain kinds are perfectly hardy in this country, others require 

 the protection of the warm house. In their native habitats, cer- 

 tain exotic species affect the most exposed and sunny situations, 

 much in the same way as the Scale Fern- (Ceterach offianarum), 

 the Maidenhair Spleenwort (Asplenium Trichomanes), and the 

 Wall Rue {Asplenium Ruta-murarid) do in this country. Others 

 only thrive under the influence of dense shade ; while others, 

 again, require constant moisture at the roots, with their heads in 

 full exposure to the action of the light, just as is the case 

 with some of our common British species. 



Geographical Distribution. — Another important feature in 

 connection with Ferns in general is the singularly cosmopolitan 

 character possessed by certain kinds which, though generally 

 given and accepted as being of British origin, are also found 

 wild in various, and, in some cases, in very distant parts of the 

 Globe. Thus, for instance, most of our Spleenworts, or 

 Aspleniums, are also found throughout the European Continent, 

 Northern Asia, North and South Africa, in North America, in 

 various parts of India, &c. The same may also be said of 

 our common Maidenhair Fern {Adiantum Capillus- Veneris), 

 which is found wild nearly all over the world. Even our own 

 Royal Fern {Osmunda regalis) is found growing plentifully on the 

 banks of rivers and streams on the Neilgherries and other 

 high mountains in India, while the common Shield Ferns, Poly- 

 stichum angulare, Lastrea spinulosa, and others, are also natives 

 of many parts of India and of North America; and another 

 example of the cosmopolitan character of Ferns is' well shown 

 in the delightful violet-scented, small-growing Lastrea fragrans, 

 which, although originally introduced into this country from 

 North America, is found to be abundant on some of the Japanese 

 mountains. 



