304 
against the bark of a young tree rown. But in 
other cases there may be enough friction to injure the bark and 
expose the cambium en a union is brought about by 
fusion of callus formed at the point of injury. In either case 
it is easy to see in the early stages what has happelieds but 
a g 
pines standing a few feet apart which were united by such a 
of grafting can now be seen on the At its greatest dis- 
tance from the parent branch it is 14 inches, thus forming a 
handle by which the specimen can conveniently carried. 
Modifications of this style of natural grafting may often be 
noticed and a branchlet may grow several feet away from the 
parent branch and then gradually return and join again at a 
point higher up the branch. : 
Natural grafting is also effected by a branch growing through 
the acute angle formed by two fairly erect branches. In such a 
position there is little movement and the small branch is soon 
Tn elm trees two or more hearts may often be found in a section 
of the timber especially if the section is taken from a point 
