All of the discolored diseased areas in the tree should be removed. Small branches or twigs nearly girdled are best cut off. Cankers in the main trunk or on limbs should be gouged out. Carefulness is the prime requisite in this work. If the disease has completely killed the cambium, the bark should be entirely removed as well as several layers of wood beneath the canker. By frequent examination, however, diseased spots may be found on the tree where the mycelium of the fungus is still in the upper layers of the bark. It is not necessary then to cut clear to the wood, but the discolored outer bark may be removed and a layer of healthy inner bark left beneath the cut. The sap may still flow through this layer. The border of the diseased area is quite distinct, but cutting should not stop here but should be continued beyond the discolored portion into healthy bark, at least an inch. The tools should be thoroughly sterilized by immersion in a solution of 1.1000 bichloride of mercury, or 5 per cent solution of formaldehyde, before cutting into the bark outside of the diseased area. Experiments have shown that a gouge or knife may carry the spores into healthy bark and new infection take place. Experiments are being carried on in the laboratory to determine the length of time which spores will live in solutions of different strengths of fungicides. It has been shown that a cut made pointed at the top and bottom heals much faster than one rounded. The edges of the cut should be made with care so as not to injure the cambium. The chips of diseased bark and wood should not be allowed to fall on the ground then to be forgotten. A bag fastened just below the canker will collect most of this material as it is gouged out and prevent possible reinfection, which might take place if the material were allowed to scatter down the bark. Canvas or burlap spread around under a small orchard tree might be sufficient to catch all of the diseased chips of bark and wood cut out of the lower infections. This diseased material should be burned together with blighted branches. After completely cutting out all of the diseased parts the cut surfaces should be either sterilized or covered with a waterproofing which combines a fungicide with a covering. Among these might be mentioned coal tar and creosote, or a mixture of pine tar, linseed oil, lamp black and creosote. The trees which have been killed by blight, or nearly girdled, have been overlooked. These should be cut off close to the ground, the stump peeled and the bark and unused portions of the tree burned over the stump. The merchantable parts of the trees should be removed from the woods promptly, as all dead unbarked wood furnishes an excellent breeding place for the blight fungus.