The canker of hard-wooded trees is brought about by one of the Nectria (_N. ditissima_), and is very common in every part of the country, affecting the oak, beech, ash, sycamore and fruit trees generally. The ash perhaps suffers most, the timber turning black and being quite unfitted for structural purposes. It is strictly parasitical, growing on wounded portions of the stem and branch, and spreads with great rapidity, attacking trees of all ages. We have known the trees in a plantation of ash to be quite destroyed by this canker, which attacks most freely those growing on wet, sour land. This should be a warning to planters to avoid such soil. The =Red-rot Fungus= (_Fomes annosus_ or _Trametes radiciperda_) attacks the roots of several species of pine, particularly the Scotch, Corsican and Weymouth, as also the Spruce and Silver Fir. It is probably the most destructive of the family, attacking living roots and spreading rapidly from tree to tree. The trees, when affected, quickly turn sickly and die, the wood becoming spongy and of a brownish colour, with distinct black spots. The only remedy is to take out affected trees and burn them root and branch, replanting the ground with beech or elm. Though one of the most destructive fungi in coniferous woodlands, its attacks are by no means confined to these alone, since it is found on the roots of several hard-wooded species, such as the filbert, hazel, birch and beech. Quite recently a nut plantation in Kent suffered severely from the attacks of this fungus, whole lines of trees being killed outright before the cause was detected. It spreads quickly underground from tree to tree, and unless eradicated, as it may easily be by uprooting affected trees and carefully destroying the mycelium, much damage may result. The =White-rot Fungus= (_Fomes igniarius_) is usually found on hard-wooded trees, and takes possession of wounds that may have been occasioned by the accidental breaking of a branch or stem injury. Oak trees suffer most from the attacks of this fungus, which is often as large as a foot across, and of a brownish colour. It is named igniarius on account of the inner surface being used as tinder, when prepared with saltpetre, especially in the old days of flint and steel. By removing the fungus and attending to the wound by cleaning away all dead and dying matter, and coating with tar, much benefit will ensue.