104 SELECTING, PLAIN^TING, AND CULTIVATION. 



low trench, covered lightly with earth, and left from 

 three to ten days, according to their condition, until 

 the bark is swollen full and plump. The wood of 

 plants is not a solid structure, but is composed of 

 cells or short tubes, separated by woody fibre. These 

 cells are the arteries and veins of the plant, in which 

 is conveyed the sap which hardens into wood and 

 bark, or is developed into fruit and leaf. 



When the tree has become dry, these cells contract 

 so much that sap cannot pass through them, and arti- 

 ficial meaias, such as are above described, become 

 necessary to restore their functions. Trees which it 

 is necessary to treat in this manner should be short- 

 ened in to a greater extent than is needful in other 

 cases, and when planted, the ground should be well 

 mulched. Frequent sprinkling and watering of the 

 branches and foliage of injured and poorly rooted trees 

 is found much more useful than the profuse pouring of 

 water upon the roots — by preventing the evaporation 

 through the leaves from exhausting the supply of sap. 



PL ANTING. 



Many persons imagine it necessary to choose a wet 

 day for planting trees. On a light sandy loam, little 

 injury would result, perhaps, from the selection of 

 such a day, but for planting upon a strong loam, or 

 clayey soil, no choice could be more injudicious. 



The earth falls in mortar or in clods upon the roots, 

 pressing them down into close contact, instead of 

 being distributed between them, and thus separating 

 each rootlet from its fellow with intervening earth 

 that would soon be filled with fibres. 



