161 PERMANENT NUBSEEIES. 



by admixture of the necessary manures, whereas it is always a 

 difficult and expensive task to correct the defects of stiff clays. 

 Moreover, a sandy soil is much more easily kept clear of weeds. 



As regards depth, it does not follow that, because the transplants 

 ought to possess short roots, not exceeding say 18 inches in length, 

 the depth of the soil should also be limited to that figure. With 

 only 18 inches of depth, the soil would nearly always be liable to be 

 overheated under a hot sun, or to become waterlogged during the 

 rains if the subsoil were mt very freely permeable; and it is always 

 safe to insist on a minimum depth of 3 feet. 



Stones in the soil also tend to overheat it, besides injuring the 

 nursery implements and interfering with the easy lifting up of the 

 plants. 



The nature of the subsoil is of little importance as long as it is 

 neither impermeable nor too freely permeable. A basis of lime is 

 an advantage, as it prevents the formation of acid humus in the 

 eoil, which it at the same time enriches by the formation of carbo- 

 nates. 



LOCALITY. With regard to the second point, locality, it may be 

 generally laid down that it should not be one exposed to early frosts 

 or to drought, nor should it be so damp as to favour the develop- 

 ment of mildew and other fungoid growth. For this reason it 

 should not be situated in a hollow or be confined in the midst of a 

 lofty mass of forest where the air circulates with difficulty ; nor 

 should it be too open or exposed to hot winds. The ground should 

 be just sufficiently inclined to allow water to drain off easily, with- 

 out, on the other hand, letting it out too fast. In hilly country, 

 however, high gradients cannot always be avoided; but even then 

 soil that holds water sufficiently well, can invariably be found. 



For the purpose of watering, it is a great convenience to have a 

 surface spring or streamlet near at hand, especially if the former 

 lies above the nursery and can be led into a channel. A Public 

 Works canal running above the nursery, would be better than 

 either. The vicinity of a tank lying above the level of the 

 nursery, but remote enough to obviate swampiness, is still more 

 to be desired. In the absence of these special advantages, a 

 well or wells must be sunk, in which case the water-holding 

 stratum ought to be as near the surface as possible. Flat 

 expanses of good soil, can often be found along the banks of small 

 rivers that run all the year round or contain perennial pools, and 

 in such places the expense of well-sinking would be saved or at 



