Cotton plants in India[g] were described by Dr. Shortt as subject to the attacks of a kind of mildew, which from the description appeared to be a species of _Erysiphe_, but on receiving specimens from India for examination, we found it to be one of those diseased conditions of tissue formerly classed with fungi under the name of _Erineum_; and a species of Torula attacks cotton pods after they are ripe. Tea leaves in plantations in Cachar have been said to suffer from some sort of blight, but in all that we have seen insects appear to be the depredators, although on the decaying leaves _Hendersonia theicola_, Cooke, establishes itself.[h] The coffee plantations of Ceylon suffer from the depredations of _Hemiliea vastatrix_, as well as from insects.[i] Other useful plants have also their enemies in parasitic fungi. Olive-trees in the south of Europe suffer from the attacks of a species of _Antennaria_, as do also orange and lemon trees from a _Capnodium_, which covers the foliage as if with a coating of soot. In fact most useful plants appear to have some enemy to contend with, and it is fortunate, not only for the plant, but its cultivators, if this enemy is less exacting than is the case with the potato, the vine, and the hop. Forestry in Britain is an insignificant interest compared to what it is in some parts of Europe, in the United States, and in our Indian possessions. In these latter places it becomes a matter of importance to inquire what influence fungi exert on forest trees. It may, however, be predicated that the injury caused by fungi is far outstripped by insects, and that there are not many fungi which become pests in such situations. Coniferous trees may be infested with the species of _Peridermium_, which are undoubtedly injurious, _Peridermium elatinum_, Lk., distorting and disfiguring the silver fir, as _Peridermium Thomsoni_, B.,[j] does those of _Abies Smithiana_ in the Himalayas. This species occurred at an elevation of 8,000 feet. The leaves become reduced in length one-half, curved, and sprinkled, sometimes in double rows, with the large sori of this species, which gives the tree a strange appearance, and at length proves fatal, from the immense diversion of nutriment requisite to support a parasite so large and multitudinous. The dried specimens have a sweet scent resembling violets. In Northern Europe _Cæoma pinitorquum_, D. By., seems to be plentiful and destructive. All species of juniper, both in Europe and the United States, are liable to be attacked and distorted by species of _Podisoma_[k] and _Gymnosporangium_. _Antennaria pinophila_, Fr., is undoubtedly injurious, as also are other species of _Antennaria_, which probably attain their more complete development in _Capnodium_, of which _Capnodium Citri_ is troublesome to orange-trees in the south of Europe, and other species to other trees. How far birch-trees are injured by _Dothidea betulina_, Fr., or _Melampsora betulina_, Lév.,