123 



DRAINAGE DISTRICTS 



AND GEOGRAPHICAL CATEGORIES 



OF PLANTS. 



Drainage Districts. — The nine districts into which North 

 Yorkshire is subdivided in the map (plate 3) which faces page 

 75, are founded upon the river drainage, and are, with ex- 

 ceedingly trifling exception, separated from one another either 

 by rivers or lines of water-shed, not like wapentakes and 

 parishes, by purely arbitrary and conventional lines of limita- 

 tioa These drainage districts are mapped out and used 

 to answer a two-fold purpose : in connection with physical 

 geography to help the mind of those who use this volume to 

 dwell with the prominence to which its importance from this 

 point of view entitles it upon the question of how our field of 

 study is made up of river-basins and what is their extent and 

 configuration : and in connection with botany to aid in tracing 

 out and illustrating the topography of its vegetation. It will be 

 observed that, with very little exception, the boundaries of North 

 Yorkshire as a whole are natural boundaries also. In this 

 part of the work it is intended to pass each of these 

 nine drainage districts under review, and to speak, as we do so, 

 of its more prominent natural features and characteristics, 

 mentioning as we pass along the towns and principal villages 

 which each includes, its hills and its glens and its waterfalls, and 

 also the more noteworthy botanical stations and the plants which 

 they produce. 



The following table gives an estimate of the area of each of 

 the districts in square miles and classifies them under the vice- 

 counties of the Cybele Britannica to which they belong. 



July 1888. 



