

A Pine Forest 



ARBORICULTURE. 



A RBORICULTURE, or the cultivation of trees ' 

 A\ and shrubs, is one of the most interesting 

 and important of the rural arts. It is a branch of 

 industry which is daily becoming a subject of great 

 national importance, not only as regards Britain, 

 but also her colonies and Indian empire. Science 

 has proved that the cultivation of trees and shrubs 

 exercises a most benign influence on the climate, 

 and on the health and death-rate of a country, as 

 well as on its prosperity. Hence, more attention 

 is now being paid to the better conservation and 

 management of forests, both at home and abroad. 

 In this country, while agriculturists are continually 

 carrying on a warfare of extermination with the 

 straggling hedgerows or scattered trees that are 

 yet common in many of the finest cultivated dis- 

 tricts, they are fully alive to the importance of the 

 shelter derived from trees when properly arranged 

 on the exposed parts of their fields, or around 

 their homesteads ; while the profusion of trees and 

 shrubs cultivated around suburban and villa resi- 

 dences, as well as in town squares and public 

 parks, clearly shews how much arboriculture is an 

 object of delight and pleasure to the people. 



To cater to the public taste and requirements in 

 this department, the utmost resources of the pro- 

 fessional arboriculturist and landscape-gardener 

 have been called into requisition, and at no former 

 period has the demand been so great as during 

 the present century. Within that period the 

 landscape of Great Britain has undergone a com- 

 38 



plete change, and many of her bleak and barren 

 hills and waste lands are now covered by thriving 

 plantations. Thus, the adjoining lands have 

 become more fertile and valuable, and the food 

 production of the country has thereby greatly in- 

 creased. 



STRUCTURE AND PHYSIOLOGY OF TREES. 



The general structure and physiology of plants 

 have been explained under VEGETABLE PHYSI- 

 OLOGY and SYSTEMATIC BOTANY, to which refer- 

 ence may be made. The stem, which chiefly 

 concerns our present subject, presents an infinite 

 variety of modifications assuming the form of a 

 globular or columnar mass, as in cacti ; or a 

 pseudo-bulb, as in orchids ; a hollow-jointed culm, 

 as in grasses ; a lofty branchless caudex, as in 

 palms ; or it may be twisted in a spiral manner 

 around other plants, or form an underground 

 rhizome, or an upright branching woody trunk, 

 such as we see in our ordinary forest-trees. But 

 all modifications of the stem are reducible to three 

 well-marked forms, which differ not only in their 

 mode of growth, but also sufficiently so in outward 

 appearance as to render them easy of recognition. 

 The three kinds of stem are : 



r. The Exogenous, or Outward-growing Stem, 

 which, in its growth, increases indefinitely in an 

 outward direction by the annual formation of new 

 layers of woody matter formed on the outside of 



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