The Vegetation of the Scottish Highlands. 99 
In a general chapter on the physical geography, the climate* 
and the geology of Scotland, Mr. Hardy shews that the Highlands 
fall naturally into an Eastern and a Western “ Domain.” The 
difference in character of these is determined partly by the geology, 
but mainly by the climate (especially rainfall), and though the 
floristic composition of the flora is very uniform over the whole 
region, the preponderance of the various plant-formations is 
markedly different in the east and west. After discussing their 
physical characteristics Mr. Hardy takes a rapid survey of the 
remains of primitive forest of the two domains, and concludes that 
two altitudinal zones—an oak zone and a pine zone—can he 
distinguished in each case, though the latter was probably much 
better developed in the east than in the west. The “districts” of the 
highlands—four in the western and five in the eastern domain—are 
then briefly characterised, and their often striking peculiarities 
brought out. 
The second part of the work is devoted to a consideration of 
the actual plant-associations now met with, under the headings of 
forests, grasslands (“prairies”) and moors (“landes.”) One of the 
chief points brought out is the dominance of grassland in the west, 
and of moorland (particularly heathland) in the east, corresponding 
with the lower rainfall and partly with the more porous rocks of 
the Grampian massif. The peat-problem is discussed, but the 
author does not consider that we know enough, in spite of the 
enormous literature of the subject, to arrive at any very definite 
conclusions as to the historical evolution of the great peat-masses. 
An important feature of the discussion of the plant-associations is 
the prominence given to the important questions of the succession of 
associations and of their evolution one from another. Many 
interesting series are given, actually observed by the author, or 
inferred from various evidence. 
A most interesting part of the work is that devoted to the 
“topographical units,” four of which are distinguished, the “carses” 
or low-lying alluvial lands around the great estuaries, the “straths” 
or broad lowland valleys, the “glens,” or valleys in which erosion is 
still going on, and the mountains, each characterised by its own 
physical features, scenery, soil and vegetation. 
In the concluding part the relation of vegetation to man is 
dealt with, in a most attractive, though necessarily cursory manner. 
This section of the work shews very clearly the influence of Geddes, 
to whose inspiring influence the author, in common with many 
