The common practice of growing trees and some shrubs and plants from root-cuttings well illustrates some of the varied peculiarities of root-structure. It may be said that all trees and plants which naturally sucker from the surface-roots, or which may be made to sucker by breaking with the plough, or cut with the spade, may be grown from root-cuttings. But this only applies to the surface-roots which are capable of developing adventitious buds naturally or when injured. The deeper water-feeding roots do not develop buds soon enough for use in propagation, but if they come to the air by soil-erosion or in other ways they soon change into surface-roots with an ample supply of starch for the development of buds and even upward growth. It is also easy to graft pieces of the surface-roots successfully, but in no case have we known the pieces of the deep roots to unite with a scion, as they are not well stored with starch.