ON THE CULTIVATION OF TREES. 323 



Mrs. B. It has been so considered, but, I am inclined 

 to think, erroneously. A thief may lie concealed, and 

 lead away a sheep or a cow at night, under cover of a 

 hedge, without being discovered ; whilst there is scarcely 

 any night so dark, that he might not be perceived on an 

 open plain. 



It is objected to hedges, that they occasion a waste of 

 ground : when necessary, therefore, they should be made 

 to occupy as little space as possible, and be thickened, by 

 crossing and engrafting the branches on each other, rather 

 than by planting a double row. An external ditch is lia- 

 ble to the same objection ; but it has the double advan- 

 tage of serving as a defence to the hedge, and of raising 

 a bank, which gives additional elevation to the hedge 

 when planted on it. When the shoots are two years old, 

 they may be crossed and fastened by a worsted thread, 

 and they will engraft of themselves ; for the friction of the 

 ligature will wound the young bark sufficiently to expose 

 the corticle vessels, and enable them to unite with each 

 other. 



Emily. The plants have, then, a double source of life ; 

 and, if one of the stems should perish, its branches would 

 be fed by those on which it is grafted. 



Mrs. B. Yes ; and the dead stem may be cut away 

 without injuring the hedge. By this system of crossing and 

 grafting the branches, the hedge becomes so thick as to 

 be absolutely impassable. Great attention should be paid, 

 not to plant hedges of shrubs which grow thin at the base, 

 or have spreading roots. The hawthorn or quickset is de- 

 cidedly the plant best adapted for hedges ; its shoots 

 branch out in such a variety of directions, and cross and 

 intersect each other so frequently, as to render all liga- 

 tures for that purpose unnecessary. 



The Paliurus aculeatus succeeds well in dry soils. It 

 is armed with two species of thorn, one of which is straight, 

 the other curved : so that the animal that would trespass, 

 if it can avoid the straight thorns, on entering the hedge, 

 has very little chance of escaping the crooked ones in 

 passing through it. 



1741. What is said of hedges, as defence against thieves'? 1742. 

 And what is said of them, as occasioning a waste of ground'? 1743. 

 How may the shoots in hedges be made to unite themselves together 1 ? 

 1744. What is said of the hawthorn for hedges! 1745. And of the 

 Paliurus aculeatusl 



