INTRODUCTORY 



Tay and Tweed as lie within a moderate distance, say 

 twenty to thirty miles, of the city, the whole being capable 

 of investigation in the course of a series of easy excursions, 

 seldom requiring more than a day for their accomplishment. 

 It is, in fact, practically the same area as that adopted by 

 Balfour and Sadler in their "Flora of Edinburgh," and 

 shown in the map which accompanies both editions of that 

 work, a section of country presenting a combination of 

 physical features peculiarly rich and varied. The counties 

 embraced are on the south, East Lothian, Midlothian, 

 West Lothian, and Peebles, with parts of the adjoining 

 counties of Berwick, Roxburgh, Selkirk, Lanark, and 

 Stirling ; and on the north, Fife, Kinross, Clackmannan, and 

 a portion of Perth. Through the centre from west to east 

 winds the Forth with its estuary and broad firth, into 

 which innumerable tributary streams from secondary valleys 

 empty their waters. Fresh- water lochs and ponds also 

 abound. The upper part of the main valley, penetrating 

 as it does the south-western section of the Perthshire 

 Grampians, is thoroughly wild and alpine in character. 

 From the rugged mountains of this north-west corner, a 

 series of sub-alpine ranges the Campsie Fells, the Pent- 

 lands, the Moorfoots, and the Lammermoors with their 

 connecting moorlands, constitute the watershed on the 

 south ; while the almost alpine Ochils, the Cleish Hills and 

 the Lomonds, mark it on the north. Between this rampart 

 of hills and the shores of the Forth, every variety of lowland 

 country is to be found fertile lands and barren commons, 

 green meadows and furze-clad hills, breezy heights and 

 secluded dells, with woods and plantations of deciduous 

 trees and pines on every side. The part of the Tweed area 

 of which we take cognisance lies largely in the pastoral 

 county of Peebles, and consists for the most part of grassy 



