In vegetative propagation the tree breeder has a very important tool. For instance, if a number of desirable phenotypes have been selected in the forest, they can be propagated vegetatively and planted under uniform conditions where it will be possible to "estimate" their genotype, without the time-consuming progeny testing. Trees propagated vegetatively from old mature trees usually will start flowering very soon after they become established; thus the necessity of doing pollination work in very large trees can be eliminated. Furthermore, it enables the tree breeders to maintain trees of a desirable genotype unaltered for an indefinite length of time without first establishing pure lines through inbreeding. Finally, it may be possible to make valuable individuals available to the forest owners for field planting if they can be propagated vegetatively in large enough numbers at low cost. Compared to propagation by grafting, the rooting of cuttings is both simpler and cheaper, if it can be done. Chestnut cuttings are, unfortunately, very difficult to root. In the past six years numerous experiments have been conducted in order to find a way to root the various chestnut species. We have tried to root dormant, as well as greenwood, cuttings, the conventional twig cuttings as well as leaf-bud cuttings; numerous hormone treatments using several different hormones in solution and as powders, over a wide range of concentrations, have been tried; a special chamber in which an automatic atomizer nozzle sprays the cuttings intermittently has been used. Results have always been poor. Dormant cuttings have broken dormancy, sent out new leaves, formed an abundance of callus on the basal end, but failed to develop any roots, and finally after several months have died. Greenwood cuttings also have failed to develop roots in almost all cases. The best results have been obtained with leaf-bud cuttings. In some cases 10 to 20 per cent have rooted; here, however, the difficulty has been the failure of the bud to break dormancy and start growth, and all the rooted cuttings have eventually died.