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on the under side of the leaf, called stomata. During dull, cold, 

 or wet weather these cells are closed ; but on a bright warm day 

 they open, and the work of the tree growth is briskly carried on. 

 The leaves collect the gases from the atmosphere, digest the car- 

 bon dioxide with the moisture, and dilute plant food from the 

 roots, and pass it down along the branches and stem to them again. 

 As this substance passes down, it takes a totally different course 

 to the sap that came up. Instead of going down through the cells 

 in the wood, it descends between the stem and the bark, and, as 

 it does so, adheres to the stem, and gives birth to the cambium 

 layer which forms the annual ring, or a year's growth of new 

 wood. It is as well to remember this growth begins at the top of 

 the tree ; if it were not so, ring-barking would be work thrown 

 away. The roots of ithe tree are also supplied with nutrition, 

 which is stored in their cells, and is used the following season for 

 future height growth. Having seen now the uses of the different 

 parts of the tree and the system adopted by nature to keep life 

 going, it is not very difficult to understand why ring-barking kills 

 a tree. When a ring of bark is removed from the stem it severs, 

 so to speak, the connection between the leaves and the roots. The 

 downward flow of sap is voluminous, as well as rapid, and if only 

 a narrow strip of bark be removed the wound is soon healed over. 

 But let a broad band be taken, the sap, as a rule, cannot repair 

 damages and the drying influence of the atmosphere and sunlight 

 cause it to perish. But even this can be healed, if paper is wrapped 

 round the ringed portion, so as to exclude air and light. Now, 

 above the cut or ring, growth, still progresses. The root still send 

 up sap. The leaves still send it down, but it cannot pass back to 

 the roots. The roots are now isolated ; they are unable to get 

 nourishment for themselves, or to store up any for next season's 

 growth. Their cells are at last emptied of nutriment. They con- 

 tain only the material procured from the soil. Nature's law no 

 longer acts. Passing up moisture to the leaves ceases, and the 

 tree dies. 



HOW TO RING BARK. 



Although this operation is simplicity itself, still, unless care is 

 taken it will result in endless trouble, and unnecessary expense. 

 More especially in the case of young trees ; in fact, the younger 

 the tree the harder it is to kill, as a rule. Before describing the 

 manner of doing the work, it will be as well to explain some often 

 misquoted terms. Suckers are, strictly speaking, shoots that grow 

 from the roots only, not from the stem. Shoots grow from the 

 stem and branches. To ring bark properly, a band of bark 

 should be removed from round the stem of the tree of sufficient 

 width to prevent the possibility of the renewal of the bark. Not 

 less than 10 inches is advisable, and in the case of gum trees 15 

 inches is not too much, as they seem to possess greater recupera- 

 tive power than other trees. Great care should be taken that the 

 bark is entirely removed, and that the stem of the tree is cut into 

 as little as possible. It is advocated by some that to give a cut 



