68 THE VEGETABLE WORLD. 
long slender branches of this elegant tree fall by their own weight. 
But the habit is not confined to this tree. The ash and other trees 
are capable of being trained to it, and gardeners avail themselves 
largely of the habit, planting the banks of water basins, ponds, 
and brooks with the one, and forming shady places on lawns by 
means of the others. The Willow is at once elegant and sad in its 
aspect. 
The branches of the Sophora of Japan (Sophora Japonica), or the 
Weeping Sophora, resemble the Weeping Willow in many respects, 
but they possess a certain rigidity at their extremities, which 
gives a tendency to resume the upward direction, Fig. 80. 
We have said that a branch may be considered as a secondary 
stem, emanating from the principal one, from which it draws its 
Fig. 81.—Propagation of layers. 
nourishment. But if we give this secondary stem or branch 
another source of nourishment, it may be separated from the 
rincipal axis which carries it, and become a free and distinct 
individual of the same species. Upon this natural fact has been 
founded the process of layering, or root-grafting, well known ™ 
horticulture; bending a flexible branch towards the humid soil 
prepared for the purpose, the gardener maintains it in its position by 
