HOW WOUNDS HEAL 125 



through the bark to 

 the cambium layer, but 

 no deeper, the cut ex- 

 tending parallel with 

 the direction of 

 growth on the trunk 

 and the main liniljs. 

 Very large limbs and 

 trunks may have two 

 or three slits made at 

 equal distances from 

 each other. This op- 

 eration is always [jcrfonned in spring just as growth begins. 

 When made the cuts are scarcely visiljle, but in a few days 



FIG. 83— HOPING STILL! 

 This oak tree keeps the bark alive aroutid the 

 decaying; stub in the "hope" to protect itself from 

 the decay creeping nearer the trunk every year. 



their edges 



ill ha 



;ivc spre 



ad. 



PIG S4 — MORE THAN THREE- 

 FOURTHS OF THE TRUNK LOST BY 

 DECAY AND BREAKAGE. YET THE 

 TREE BEARS APPLES ANNUALLY. 



pcrliaps half an inch apart. 

 Sot.in new cells will devcbip 

 from the cambium and the 

 wound be closed with new 

 tissue. In no way docs this 

 iK'aling process differ from 

 tliat following the splitting 

 of bark in forest and other 

 trees. ( Compare 09. ) 



115. Limb connections 

 with the trunks of trees. — 

 Cross sections of tree trunks 

 marie at certain points will 

 show bow limbs are pro- 

 duced and how they leave 

 records of their develop- 

 ment and decline in case of 

 injury (Fig. 79). When a 

 liml) starts while the trunk 

 is small its initial point will 

 be found close to the center 

 of the trunk, and as it grows 

 it will enlarge, and its base 



