STRUCTURE AND GROWTH 21 



The ideal incision is egg-shaped or oval, with the 

 longer axis lengthwise of the trunk or limb in 

 which the incision is made. As it happens, this 

 is the shape of the wound usually made in cutting 

 off a limb close to the trunk. It is highly desir- 

 able that the incision be as narrow as possible, but 

 its height, or dimension lengthwise of the trunk 

 or limb, is not so important. The flow of sap is 



li 



Four incisions in trees, the one at the left being the most dam- 

 aging and slowest to heal ; the one at the right least damaging 

 and quickest to heal 



not much more seriously interfered with by a cut 

 six inches wide and three feet high, than by one 

 of the same width only one foot high, and will 

 heal as quickly. In some trees, especially apples 

 and beeches, the bast fibers are often laid on in 

 gentle spirals around the trunk, indicated out- 

 wardly by the fissures and ridges in the bark. In 

 such cases the incisions should follow the direction 

 of the fissures. 



The proper location of incisions, when choice 

 can be exercised, is as important as shaping them 

 correctly. When there is a vigorous ridge in the 



