TOPOGRAPHY AND PHYSICAL GEOGRAPHY. 1 27 



For instance, the number of Montane species which grow in 

 the West Tees district is 77 and in the East Swale district is 23. 

 If the total number of individual wild plants which grow in the 

 two districts could be counted, I have no doubt the squares of 

 77 and 23, that is to say 5929 against 529, would represent 

 more truly the relative proportion of the two, in respect of the 

 number of individual plants of species of the Montane category 

 which they would be found to yield, than would the unmultiplied 

 figures. In this way it is intended that the analytical tables and 

 lists of rarer plants which are given under each drainage district 

 should be considered as data in illustration of its physical geo- 

 graphy. About a dozen species are given both as Montane and 

 Xerophilous, but except these, each is given under a single 

 category only. 



July 1888, 



