Parasitical fungi, not content with damaging corn and potatos, are also very injurious to garden produce; cabbages, beans, peas, celery, and onions, each of them cherish and faster some unbidden visitor; fruit trees, as pears, plums, peaches, filberts, and walnuts furnish a residence for some unwelcome intruder.
Flowering plants, grown for their beauty, are much injured, and sometimes killed, by parasitical funguses; witness the rose trees and hollyhocks. Two years out of three hopyards are rendered unproductive by attacks of an Erysiphe.
Timber trees do not suffer much while in growth, yet it is curious to number the varieties of fungus found on them. M. Wessendorf says that "seventy-four attack the lime, of which eleven reside on the leaf; 114 the spruce fir, and no less than 200 the oak;" among the latter are reckoned those funguses whose ravages in timber-built ships have occasioned a loss in fourteen years estimated at twenty millions, and which in church and domestic architecture produces great annoyance and expense by causing dry rot. Merulius lacrymonus, Polyporus hybridus, and a Thalephora are the funguses which prey on sound timber; their mycelium creeps between the cells, and decomposes the lignin and cellulose; the Merulius has a rusty-coloured irregular stemless pileus, from whose gills a liquid constantly exudes.
If the useful plants of other countries are examined, we find in the south of Europe olives, oranges, and onions damaged by a fungus that envelopes their leaves in a covering of soot: in the Atlantic isles and Frances the Oidium Tuckeri destroys the grape vine. This fungus first appeared in an English hothouse, and thence has spread in all directions. Our friend, M. Cornu, told us last October that another fungus had lately appeared on the vine at Narbonne, causing a disease called Anthracnose. In some parts of Italy the cultivation of the silkworm has been suspended because it is attacked and destroyed wholesale by a species of mould somewhat resembling that which kills flies in the autumn, and leaves them adhering to the glass in our windows, surrounded by a cloud of white spores. In America the maize in often much injured by a smut that causes large and curious distortions of the grain end cobs. The plant which of all others is the most important for clothing purposes—the cotton plant—has two formidable enemies. One attacks the leaves, the other the pads.
Some manufactures are much impeded by the growth of moulds. Bleaching cannot he carried on in the fields on account of moulds growing and causing unsightly and irremovable blotches on the fabric. The preparation of gelatine, maccaroni, lime juice, and wines requires precautions to be taken to prevent access of air containing spores of funguses. It would not be difficult to extend the list of noxious funguses, but enough has been said to show that man’s person, food, clothing, building materials, and occupations are all injured by divers species of fungus. In proportion to the amount of injury they cause, they become important. It must be desirable, therefore, that their structure, habits, and life-history should be carefully studied, so that advantage may be taken of every opportunity of lessening or preventing their injurious effects.
