2 MR JOHN MACRAE ON THE FLORAS 
I purpose, then, in this paper, first of all to try to get 
a general view of the plant-geography of these counties, 
and then to give some of the particular differences*in: the 
plant-associations that seem to me most noteworthy. — 
I. GENERAL. 
Have you ever noticed, say, in the Limits of Distribution 
given in Hooker’s Student's Flora, how the general north- 
ward distribution in Scotland was not a parallel of latitude, 
but rather a line striking slantwise across from south- 
west to north-east—much further north on East than West ? 
I take at random the Umbelliferz, and here are the most 
of the Scottish limits given :— 
Eryngium maritimum—From Aberdeen and Argyll 
southward. _ 
Smyrnium Olusatrwm—From Aberdeen and the Clyde 
southward. (srorie 
Apium graveolens—From Perth and Argyll southward. 
Aithusa Cynapiwm.—From Elgin and the Clyde south- 
ward. 
Meum Athamanticum.—North to Aberdeen and Argyll. 
From this we deduce our first principle: THz East sHows, 
IN PROPORTION TO ITS LATITUDE, A MUCH GREATER FLORAL 
VARIETY THAN THE WEST. 
This, of course, is a general statement, and several plants, 
as we shall see, belong rather to the West than to the East ; 
but here it is sufficient to note the fact. 
Again, not only is the variety of forms less, but there are 
actually fewer flowers in the West than in the East. It 
would seem as if circumstances in the West were more 
favourable to the production of cryptogams—say, mosses 
and lichens—but less favourable to phanerogamic evolution, 
which is what we are concerned with in this paper. 
Take a train journey across our belt of country—e.g., 
by the Caledonian Railway from Edinburgh to Gourock, 
which traverses the country at almost the same latitude 
throughout. The merest look through the window at the 
