256 



Principles of Plant Culture. 



healed from the cambium of the latter. In woody 

 plants, there is usually a more or less distinct swelling 

 about the base of a branch (Pig. 153), produced by the 

 cambium of the supporting member and just beyond 

 this swelling, a more or less distinct line marks the 

 point where the cambium of the branch and of the sup- 

 porting members unite. In a healthy tree, a wound 

 made by a branch of reasonable size, cut off at this 



Fig. 153. Fig. 154. Fig. 155. 



Fig. 153. Showing the proper place to make the cut in pruning. 

 A wound made by a cut on the dotted line A-B will be promptly 

 healed. One made on the line C-D or E-F will not. In Fig. 154 

 the lower branch was cut o£E too far from the trunk. 



Fig. 154. Showing how to make the cut in pruning large branches. 

 The upper cut, all made from above, permits the branch to split down. 

 The left cut, first made partly from below, prevents splitting down. 



Fig. 155. Pruning to an outside or inside bud. Cut as in the figure, 

 the uppermost bud would form a shoot that tends to vertical. Cut on 

 the dotted line, the uppermost bud would form a shoot tending to 

 horizontal. 



line, will usually heal promptly, but if the cut is made 

 much farther out, it will not. 



"Wounds so large that they cannot heal promptly 

 should be painted with lead and oil paint to preserve 

 the wood. 



419. Unhealed Wounds Introduce Decay into the 

 heartwood of trees, since the cells of the heartwood 



