Of the various species used the native sweet chestnut, _Castanea Americana_, and the European, _C. vesca_, appear entirely useless in breeding for disease resistance, as the hybrids are destroyed by the blight fungus as soon as, or even before, they reach bearing age. The tall, or tree, forms of native chinquapin, sometimes grouped under the botanical name of _Castanea arborea_ but which appear to be only natural hybrids between the sweet chestnut and the bush chinquapin, may also be regarded as useless for the purpose. The hybrid progeny show slight powers of recuperation but, in our plantings, do not sufficiently recover to make useful trees. The Rush chinquapin sometimes resists infection under natural conditions for several years but quickly succumbs when attacked, but its hybrid seedlings develop practically no resistance. The common bush or dwarf chinquapin, _Castanea pumila_, widely distributed over the Atlantic States, is not as readily infected by blight as the chestnut, many individuals under cultivation and in the wild resisting attack for an indefinite time, while the creeping species of Florida and South Georgia, _C. alnifolia_, appear practically immune in nature but succumb to artificial inoculation with the blight virus The smooth bark and shrubby forms of these dwarf chinquapins probably account to a very great extent for the limited damage caused by blight under natural conditions. Next in degree of resistance comes the wooly-twigged Chinese chestnut, _C. molissima_. There are established at Bell Experiment Plot over nine hundred Molissima trees grown from nuts collected near Tien-Tsin, China, in 1911. These trees in their eighth year of growth have borne excellent nuts, rather larger than those of our native species, in some quantity for three successive years though, owing to extensive locust injury last season, there is practically no crop this year. The trees average twelve or more feet high and are thrifty growers when not too greatly afflicted by blight. No summary of disease injury has been taken, but probably over 80 per cent of the trees show infection many of which are making attempts to heal which are often very successful. This species is native to Eastern China and has long been accustomed to the _Endothia_ fungus, developing in the course of time a very considerable degree of resistance to it. From present appearances the Chinese chestnut may be grown in orchard form with no greater loss from disease than the pear from its particular form of blight. It hybridizes well with the Japan chestnut and both of the dwarf chinquapins, but this progeny is not yet sufficiently developed to warrant judgment.