222 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 
but we will pass over this part of the chapter with the remark 
that it is intended to lead up to what follows as regards drainage 
and amelioration of unfavourable soils. This part of the 
chapter is treated in an eminently practical manner. The 
results of Continental experience, as given by Buckhardt, are 
here and there intercalated to illustrate the various measures 
and methods recommended. The forester will find much useful 
information to guide him in carrying out such operations. 
In Chapter II. the general sylvicultural characteristics of 
British forest trees, and the different classes of woodland crops, 
are discussed, and Dr Nisbet deals in detail with the special 
peculiarities of our chief forest trees in relation to climate, soil, 
light and shade, shape of root-system, stem and crown, rate of 
growth, and regenerative power and longevity. 
The question of normal density of timber-crops is very carefully 
treated, both from the Continental standpoint and as it affects 
home woodland crops. 
The three definite forms of woodland crop—coppice, coppice- 
with-standards, and high-forest—are described in detail, and the 
chapter concludes with an examination of the relative 
advantages and disadvantages of the three forms of crop. 
Speaking of highwoods, which are really the only form of 
woodland crop now of importance to us (in Scotland at any rate), 
Dr Nisbet emphasises what has hitherto been almost wholly 
disregarded or left out of account, even by the best of our practical 
foresters, namely, that highwoods can never lead to exhaustion 
or deterioration of the soil so long as this remains protected by 
a sufficient leaf-canopy ; but that, on the contrary, especially in 
the case of such trees as Scots pine and spruce, which make 
small demands on the mineral strength of the soil, the nutrient 
salts in available form at the end of the rotation may be 
considerably in excess of the quantity which was present when 
the original crop was formed. We think it may safely be con- 
ceded that until within the last few decades, when the scientific 
methods of forestry followed on the Continent began to be 
studied in this country, the importance of maintaining a proper 
covering of foliage as a means of improving the forest soil had 
been entirely ignored in Britain. Many foresters who long ago 
rejected the older arboricultural methods in dealing with woods 
grown for profit, and who otherwise, perhaps, if given opportunity, 
would not have come far short of Continental foresters in their 
