382 THE BOOK OF THE LANDED ESTATE. 



is a slow-growing tree. The timber is very hard. It is, however, chiefly 

 grown for the fine effect of the large clusters of yellow flowers which it 

 throws out in a drooping form. 



The Common Thorn (Crntcegus oxyacantha). This does not come to 

 any considerable timber dimensions in this country ; it is more of an 

 ornamental bush. Its greatest use is in forming hedges, and for this 

 purpose it is invaluable. If trained in a park or pleasure-ground, it is 

 a fine-looking plant. Its flowers are sweet scented, and in the autumn 

 its berries are very pretty. 



The Huntingdon Willow (Salix alba, Linnseus). This is a native 

 of Europe, is easily cultivated, and grows to a height of from fifty to 

 sixty feet. It grows very rapidly. Its timber is in much request, and 

 is used for the same purpose as the poplar. It is a very graceful and 

 ornamental tree. 



The Bedford Willow. A native of Britain. Is a rapid grower. It is 

 found at from sixty to eighty feet in height in this country, and is 

 worthy of being grown for its timber qualities. 



The Osier Willow. This is common, and is grown very profitably for 

 the making of baskets, hampers, &c. 



The Tulip-Tree (Liriodendron tulipifera). This is a native of North 

 America, and attains a considerable height in the south of England. Its 

 timber has not been found to be very durable. It is cultivated in this 

 country as an ornamental tree having a bushy growth and curiously- 

 shaped leaves, which give a fine contrast when mixed with other trees. 



The Holly (Ilex aquifolium). This plant attains a considerable size 

 when grown in a good soil suitable to it. The timber is firm and close, 

 and of a white colour. It is much used by cabinetmakers, turners, and 



SECTION 8. Tfie Thinning of Plantations. 



The leaves of trees are indispensable to their growth. Professor 1 

 Lindley, in his ' Introduction to Botany,' states that " leaves are at once 

 organs of respiration, digestion, and nutrition. They elaborate the crude 

 sap impelled into them from the stem, decomposing its water, adding to 

 its carbon, and exposing the whole to the action of the air ; and while 

 they supply the necessary food to the young tissue that passes downward 

 from them and from the buds, in the form of alburnum and liber, they also 

 furnish nutriment to all the parts immediately above and beneath them. 

 There are many experiments to show that such is the purpose of the 

 leaves. If a number of rings of bark are separated by spaces without 

 bark, those which have leaves upon them will live much longer than 



