Parallel to these early experiments, I was grafting in the same family as the hickories, known as the walnut, or _Juglandaceae_ family, using wild native butternut (_Juglans cinerea_) as a stock for grafting to such varieties as the Thomas, Ohio, Stabler and Ten Eyck black walnut (_J. nigra_). Some of these trees, so grafted, exist today, being more than 25 years old, and they have never borne more than a hatful of walnuts to a tree, even when they became large trees. Most of them are entirely barren year after year. I often remarked to persons who were interested in this phase of my work, that the black walnut was non-productive on the butternut root system, but it was very evident that there was not completecompatibility because the walnut scion greatly outgrew the butternut stock causing a marked difference in their trunk diameters just below and above the union. This great difference, the butternut being so much smaller, was no doubt the cause of a shortage of food supply elaborated through the bark circumference which limited the top to a mere growth of leaves, not leaving sufficient additional supply for the growth of fruit. My observation among the hickories, with which I did far more experimental work than with the walnuts, was beclouded by the fact that many successful, apparently compatible varieties, grew and throve on the native bitternut stock without bearing fruit, except for just a few nuts occasionally; and yet there was no apparent difference between the scion diameter and the trunk diameter, nothing like the overgrowth of the black walnut when grafted on butternut. So it took many years and a different growth phenomenon to open my eyes as to what was the trouble in getting hickories to bear on foreign root systems. The final solution of the problem was determined by my observation this year of grafted hickories of several sizes and ages were Weschcke shagbark (_C. ovata_)[33] scions and other hickory scions, such as Siers, Bridgewater, Deveaux, Beaver, and Fairbanks have been grafted on the same tree to act as pollinators for the Weschcke, which is devoid of pollen.[33] This year particularly, the difference in rate of growth between two varieties grafted on the same stock was very apparent; in every case all other varieties greatly exceeded the growth of the Weschcke hickory, but in many cases, only the Weschcke hickory had any nuts growing on the graft, and if there were any nuts on another graft, there were but a few. In practically all cases, the diameters of the scions of varieties of hickory other than the Weschcke were at least twice the diameters of the Weschcke grafts, and the growth of all varieties so grafted was healthy and vigorous and thoroughly compatible with the native bitternut hickory root system.