OF THE EAST AND WEST OF SCOTLAND COMPARED. 5 
the heavier rainfall on the West, and—what does not 
necessarily go along with it—a climate generally more 
humid. This, by washing away pollen, for example, is un- 
favourable to phanerogamic development, though, with 
regard to cryptogams, probably the reverse is the case. 
Again, the strongest wind on both sides is the west. For 
this we have infallible evidence in the slope of wind- 
swept trees, even about Edinburgh, not towards the West, as 
we would have expected, but towards the East. 
Now this wind comes with greater force on the West, and 
is there charged with more moisture. From this difference of 
climate it follows that, leaving aside the Flora of the corn- 
field and plants likely to have been aided by man in 
their introduction—eg., Common Dandelion—we are likely 
to have a greater variety of Xerophytic vegetation on the 
East and of Hydrophytic on the West. By these terms I 
mean the plants requiring a minimum of moisture for their 
sustenance, and those requiring a maximum of it—desert 
plants on the East, marsh plants on the West. 
Of course the greatest class of Hydrophytes is the mosses, 
and with these we do not deal, but even among the 
phanerogams the result is noticeable ; and this brings us at 
last from the consideration of the Baieral subject to a more 
particular survey. 
Finding that a mere desultory idea of things was not 
quite saeivient for our purposes, I have made out a series 
of statistics from the “Topographical Botany of Scotland,” 
a series of papers by Professor Trail, of Aberdeen, still, 
unfortunately, unfinished, which began to appear three 
years ago in the Annals of Scottish Natwral History. 
First I have taken some outstanding Xerophytes and 
Hydrophytes, and then a few typical orders, and compared 
their standing in the different vice-counties I mentioned at 
the beginning, from Berwick across to Cantire. I have noted 
their occurrence in each county, then struck an average 
for three groups:—(1) East Lowlands, 81-83; (2) West 
Lowlands, 75—77 ; (3) South-West Cipklants, 100- 101. 
In the tables x means native; + means introduced. 
