284 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 
pines and firs. The sycamore is the hardiest of all in such situa- 
tions, the beech, willow, ash, and poplar following in succession. 
Coniferous trees form valuable timber in much poorer soils 
than hardwoods. In fact, the quality of the wood is generally 
inversely as the quantity, and is accordingly impaired when the 
trees are planted where their growth is very rapid. As has 
been already remarked, a north or north-west exposure is to be 
preferred for the growth of exotics, as they are less excitable in 
the early part of the growing season in such situations, and hence 
are less liable to injury from late frost, cold south-east winds, ete. 
As regards the propriety of having woods in a mixed or in a pure 
condition, much might perhaps be said in justification of either 
method ; but, ceteris paribus, if the soil is suitable for different 
varieties of trees, it is always safer to use different varieties than 
to depend on one, although this mixed condition need not 
necessarily be maintained throughout the whole life of the trees 
composing the plantation. 
10. SELECTION oF PLANTS. 
Much of the future success of a plantation depends on a 
careful selection of plants. It is only when the planting of large 
enclosures is contemplated that it will pay to form nurseries in 
their vicinity for the purpose of raising the necessary plants ; 
although it must be admitted that trees so raised are hardier, 
and have a better chance of at once establishing themselves when 
permanently planted out. Some condemn the system of procuring 
plants from public nurseries suitable for immediate planting, and 
recommend as an improvement the purchase of seedlings there- 
from, and the growing of them in a home nursery till they attain 
to size suitable for planting in the woods. Now, as the home 
nursery, as a matter of convenience, is often located in the most 
sheltered part of the estate, it is very questionable if any 
advantage can be secured by such a course of procedure. If, 
however, it occupy a well-exposed site, or is situated in the 
vicinity of the land to be planted, the practice has much to 
recommend it. 
From the extensive nature of the operations in a public 
nursery, the professional nurseryman can always command at 
the cheapest rate the amount of skilled labour and attention so 
necessary for the successful rearing of seedlings. These he can 
