50 DATA FOR DETERMINING 



the flora of the counties to which it relates, than on the 

 distribution of plants within them. Nevertheless there is 

 some valuable information on the latter topic, and it is to 

 be regretted that a scale, showing the absolute and com- 

 parative elevation to which the species ascend or descend, 

 was not formed by careful examination of the mountain 

 tracts, and an endeavour made to connect such with expe- 

 rimental observations on the humidity and temperature 

 at different heights. This, it is apprehended, would be 

 most useful in a treatise having reference to a very limited 

 extent of latitude, the surface of which rises to a consider- 

 able elevation. The influence of soil, or subjacent rocks, 

 is also a fitting subject for local essays ; and this Mr. 

 Winch has been alive to in various of his writings. Mr. 

 Macgillivray has an able paper " On the Vegetation of 

 the Dee," in vol. v. of the Wernerian Memoirs, and 

 copied into Anderson's Guide to the Highlands. The 

 plan and method of this essay make it a good model ; but 

 it is rather too general, too much wanting in precision of 

 detail, to give exact notions on the distribution of species. 

 These constituted the principal, if not the only, works 

 published on our present subject before the year 1832, 

 when my own investigations commenced. Since then, 

 some papers thereon have been contributed by me to the 

 Edinburgh Philosophical Journal, the Magazine of Na- 

 tural History, and the Companion to Curtis's Botanical 

 Magazine. Outlines (rather too hastily put together) 

 were privately circulated in 1832, with a view to draw 

 forth information and assistance from others. Several 

 correspondents have liberally supplied such; and it is 

 hoped that botanists, resident near our higher mountains, 

 will ere long bestir themselves ; and, if wishing to write at 

 all, not confine themselves to the mere list-making labour 

 of a local Flora. Indeed, our most recent Floras do 

 already exhibit an improvement in such respect, as, for 

 example, the Flora of Berwick. 



