Another very striking result brought out by the inoculation work was that of the 158 inoculations on branches and basal shoots of the resistant trees, only nine had been girdled after one month's growth, while in the same time 16 out of the 32 non-resistant Staten Island trees were girdled. At the end of the second month, the results were still more striking. Then, in the Staten Island trees, 22 out of 32 were girdled, while in the inoculations on the basal shoots and branches of resistant stock only 22 out of the 153 resulted in girdling. This striking difference was not due to smaller diameters of the Staten Island trees, for particular pains were taken to have them approximately equal to the branches and shoots inoculated in the resistant trees. SUMMARY OF EVIDENCES OF RESISTANCE We may summarize the evidences of resistance as follows: 1. The results of the inoculation tests show that the fungus grows in these trees on the average from 1/4 to 1/3 as fast as in ordinary chestnut. 2. The occurrence of the trees in a neighborhood long subjected to the disease, and their presence among the trees of individuals long since dead. 3. Indications of the long period the disease has been present in the trees themselves; such as bare weathered tops, and healed cankers. 4. Peculiarities of the bark; such as extensive development of the callus tissue, and the presence of a peculiar substance or white secretion which is particularly conspicuous in cases of marked resistance. IS THE DISEASE RESISTANCE HERE AN HEREDITARY CHARACTER? As to whether this disease resistance is an inherent character and will be transmitted from generation to generation, or is only the result of particularly favorable environmental conditions such as soil, light or moisture, is a point of great practical importance. I believe that further work will prove that the resistance is heritable, for the following reasons: 1. The resistance is not due to a particularly favorable environment of the trees, for the three groups grow in very different soils and under varying conditions of light and moisture. 2. The finding of the trees in colonies points to a genetic variation. At first I was unable to account for the grouping of the trees, for I had expected to find immune or resistant trees singly, here and there. But if we adopt the hypothesis of a heritable protoplasmic variation--something in their "blood," so to speak, the explanation is easy. We know that chestnut fruits or nuts do not travel far, like the seeds of willow, poplar, maple or ash, and therefore, in any given stand of chestnut, if we could go back from generation to generation into earlier time, most probably the majority of the trees would be found to have arisen from a common ancestor, although of course a few outsiders would have found their way into the group, carried by squirrels or other animals.