534 



CONSERVATION 



thrives or decays. In the tree there is 

 a circulation that is as real and vital, 

 and necessary to its existence, as that 

 in the human body. The tiny feeding 

 rootlets take up the liquid food from 



A TYPICAL CAVITY 



Cherry Tree on Estate of W. B. Thompson, Yonkers, N. Y. Note Front and 



Rear Openings 



tlu- soil, and send it up through the 

 cells of the wood fiber to the leave-, 

 where it is transformed into the tree- 

 food, and returned under the 

 bark, in what is known a- the 

 cambium layer, building as it 

 goes, and finally again reach- 

 ing the little rootlet- that are 

 so necessary to the life of the 

 tree. The tree breathes; it 

 breathes through it- leave-, 

 and through its bark, and 

 through its roots. It has it- 

 time of rest and activity. 

 There is a wonderfully inter- 

 esting reciprocal relation be- 

 tween the roots and the leaves. 

 The roots are the organs that 

 take up the food, and the 

 leaves are those that digest it. 

 If the roots are healthy there 

 is plenty of food to dige-t : 

 and if the leaves are healthy, 

 there is an abundance of material 

 from which to build. Each is de- 

 pendent on the other: if both are 

 healthly, the life of the tree is vig- 



orous, but if one is destroyed, the other 

 perishes. The transformation of the 

 sap into tree- food is extremely inter- 

 esting. This takes place in the leaves, 

 where the sap is spread out to the action 

 of the sun and the atmosphere. 

 The oxygen, which is so nec- 

 essary to our existence, is ex- 

 haled, and the carbon dioxide, 

 so dangerous to human life, is 

 absorbed and combined with 

 the elements in the sap, to 

 make the food with which the 

 tree build-. 



With this understanding of 

 the principles involved in the 

 life of the tree, let us consider 

 the troubles that arise from 

 their violation, and which it is 

 the business of the tree sur- 

 geon to remedy. In general, 

 they include the following: 

 cavities. splitting crotches, 

 dead branches, destruction of 

 the roots, and unfavorable 

 root conditions. in-ert pest-, 

 and general di-ea-e-. fungus growths, 

 ga- and electricity, clinging vines, the 

 over-thickness of the top, interfering 



A TYPICAL CEMENT FILLING 

 Same Tree as Above. Contou.- ot Tree Preserved 



branches, lack of sunshine, and other 

 conditions unfavorable to the leaves. 



Perhaps the one deserving fir-t con- 

 -ideration is the cavitv and it- treat- 



