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CHAPTER XI. 
LOCAL DISTRIBUTION OP FERNS AND THEIR ALLIES. 
In tracing out the geographical range of the Ferns in 
the British Isles, we shall follow the plan originated by 
Mr. W atson, and improved upon by Mr. Moore, of di- 
viding the kingdom into provinces, and shall in other 
respects avail ourselves of the valuable aid of Mr. Moore, 
as of a well-skilled pioneer. 
According to this plan, we trace a central line from 
the south coast of England to the Caledonian Canal, 
making the line adapt itself to the boundaries of coun- 
ties, thus cutting the island of Great Britain into two 
divisions. We partition off the divisions into provinces, 
— each one watered by some river, more or less impor- 
tant. The various homes of the species are collected 
from the notes of all the most eminent writers on the 
subject, and from those of the leading botanists, Mr. 
Moore’s list serving as the foundation for the structure. 
The following are the provinces which, according to the 
above plan, Great Britain and Ireland are divided into — 
1. Peninsula. Cornwall, Devon, Somerset. 
2. Channel. Hants, Sussex, Dorset, Wilts. 
3. Thames. Herts, Middlesex, Kent, Surrey, Berks, 
Oxford, Bucks, Essex. 
