32 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 
IV. Zhe Laying-out of a Mixed Plantation, and its Main- 
tenance for the first Twenty-five Years. By DonaLtp M. 
MacpDoNnaLp, Assistant Forester, Alnwick Castle, Northum- 
berland. 
The reasons for mixing different kinds of trees in woods are 
that this secures— 
1. Protection against fungi, insects, etc. 
2. Introduces trees which are perhaps more valuable as 
thinnings than the principal species. 
3. Reduces the cost of planting by using cheap trees, which 
act as nurses to the more expensive ones forming the 
bulk of the plantation. 
4. If one species fails, another is there to take its place. 
5. The condition of the soil is improved by interplanting 
heavy-foliaged trees along with thin-foliaged ones. 
Against the above advantages, reasons might be given in 
favour of growing woods pure; but, with several classes of trees, 
mixed planting is the proper course to adopt in starting them. 
I shall therefore consider the subject from the following points 
of view :— 
1. Formation of Mixed Woods.—(1) Fencing; (2) draining; 
(3) cleaning the ground; (4) laying out roads and rides; (5) 
treatment of the plants in the nursery; (6) planting; (7) kinds 
of trees suitable for mixing; (8) system of mixing; (g) shelter- 
belts. 
2. Maintenance for Twenty-five Years after FPlanting.—(1) 
Beating-up and cleaning; (2) protection against game, vermin, 
and fungous diseases; (3) thinning. 
I. FORMATION. 
1. Fencing.—The first step to be taken in the formation of any 
plantation is to erect suitable fences to protect the trees against 
the inroads of sheep, cattle, and vermin. 
(a) Fences against Sheep and Cattle—There are many different 
styles of erecting post-and-wire fences, but the most effective and 
cheapest in the long run is one consisting of either creosoted 
pine-wood, larch, or oak straining-posts 7 ft. 6 ins. x 6 ins. x 6 ins. 
