APPENDIX. 415 



performed. The leaf is in reality a natural contrivance for exposing a 

 large surface to the influence of external agents, by whose assistance 

 the crude sap contained in the stem is altered, and rendered suitable to 

 the particular wants of the species, and for returning into the general 

 circulation, the fluids in their matured condition. In a word, the leaf 

 of a plant is its lungs and stomach traversed by a system of veins."* 

 All the pruning, therefore, that is necessary, when a tree is properly 

 transplanted, will be comprised in paring smooth all bruises or acci- 

 dental injuries, received by the roots or branches during the operation, 

 or the removal of a few that may interfere with elegance of form in the 

 head. 



Next in importance to the requisite care in performing the operation 

 of transplanting, is the proper choice of individual trees to be transplanted. 

 In making selections for removal among our fine forest trees, it should 

 never be forgotten that there are two distinct kinds of subjects, even 

 of the same species of every tree, viz. those that grow among and 

 surrounded by other trees or woods, and those which grow alone, in 

 free open exposures, where they are acted upon by the winds, storms, 

 and sunshine, at all times and seasons. The former class it will alway? 

 be exceedingly difficult to transplant successfully even with the 

 greatest care, while the latter may always be removed with compara- 

 tively little risk of failure. 



Any one who is at all familiar with the growth of trees in woods or 

 groves somewhat dense, is also aware of the great difference in the 

 external appearance between such trees and those which stand singly 

 in open spaces. In thick woods, trees are found to have tall, slendei 

 trunks, with comparatively few branches except at the top, smooth and 

 thin bark, and they are scantily provided with roots, but especially with 

 the small fibres so essentially necessary to insure the growth of the tree 

 when transplanted. Those, on the other hand, which stand isolated, 

 have short thick stems, numerous branches, thick bark, and great 

 abundance of root and small fibres. The latter, accustomed to the 

 full influence of the weather, to cold winds as well as open sunshine 

 have what Sir Henry Steuart has aptly denominated the " protecting 

 properties" well developed ; being robust and hardy, they are well cal- 

 * Theory of Horticulture. 



