Missouri Botanical 
Garden Bulletin 
Vol. V St. Louis, Mo., June, 1917 No. 6 
TREE SURGERY 
Tree surgery is rapidly gaining in importance and popu- 
larity, as people are beginning to appreciate the value of 
preserving their trees. However, there would be very little 
need for it if trees were properly planted, well nourished, 
and cared for during their lifetime. It is seldom realized 
that trees need fertilization as well as other plants, and the 
stronger and more vigorous the tree the greater will be its 
power of resistance to entrance of insects and disease. Mal- 
treatment of trees is common, nails being driven into the 
bark, wire girdled around the trunk, bark scraped and 
scarred by lawn mowers, and limbs broken off, and it is the 
object of tree surgery to remedy the damage done by such 
conditions. Its popularity is due to the spectacular effects 
achieved and the influence of “tree doctors’ who shroud 
the work in mystery and foster the impression that a certain 
inner communion is necessary between them and the tree 
to attain successful results. The operations, however, are 
simple if tree structure, nature of decay, and principles of 
treatment are thoroughly understood. 
The trunk of the tree serves the functions of supporting 
the foliage and acting as circulation medium between the 
roots and the leaves. The roots absorb moisture and min- 
eral constituents from the soil, which pass through the 
trunk up to the leaves in crude liquid form. Through the 
agency of the green chlorophyll particles in the leaves this 
crude sap is converted into sugar and starch, and is then 
disseminated through all the portions of the tree as the 
digested sap which is responsible for the nourishment and 
consequent growth. The cross-section of the trunk, fig. A, 
shows four separate concentric portions: the heartwood in 
the center, next the sapwood, then a very thin layer of 
cambium, and on the outside the bark. The most import- 
ant layer from the standpoint of tree surgery 1s the cam- 
bium. It is the growing part, healing wounds, covering 
cavities, and each year laying a thin layer of cells over the 
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