BOTTLYTIS, a genus of fungi, of the division hypliconyeetes, containing many of the plants commonly called MOLD (q.v.) and 3111.nEw (q.v.). The plants consist of a mycelium (see Fus(u) of more or less entangled threads, which are composed of rows of cells, with shoots of the same nature rising up from them, and bearing the fructification at their extremity. Some of them attack the fibers of vegetable fabrics, such as linen and cotton, in damp places, the decayed stems of plants, decaying fruit, etc. Some are found on living animal tissues, whether always previously diseased or not is It question still unsettled, although the probability appears to be that they make their appearance only where there is already disease, which, however, they modify or entirely change. A remarkable species of this section of the genus is the M•SCARDINE (q.v.), or SILK WORM ROT.—A section of the genus, in many respects of particular interest, and which some botanists have endeavored to separate into a distinct genus, consists of species which grow among living vegetable tissues. The threads of the myerlitan creep among the loose cells of the under side of the leaves, and send up their fertile shoots through the stomata (see LEAVES and STOMATA). Many of the species are extremely destructive to particular plants, as B. parasilica to turnips. But B. infestans is, of all the species, the subject of greatest interest, the potato disease being confidently ascribed to it by some observers, among whom is sometimes named Mr. Berkeley, and the opinion of no
living botanist is entitled to greater respect upon a point connected with this branch of time science; but Mr. Berkeley himself states his opinion very guardedly. "The decay of the leaves and haulm in the potato murrain," he says, " is certainly due to botryas Weston* ; and its appearance in the diseased tissues of the titbers, when exposed to the air, makes it at least probable that it has a close connection with that destructive mur rain, which, in many instances, does not appear alone, but accompanied by other dis eases. The mold may be traced spreading round the edges of the brown spots on the leaves, and soon destroying the tissue on which it was developed." (Art. Botrytis in Morton's Cyclopedia of AgrIculture.) The destruction results not only from the fungus feeding upon the juices of the plant, but from its obstrticting the elaboration of the sap and all the processes which in a healthy state take place at the surface of the le:IL—Thu whole subject of the propagation of fungi of this kind is involved in great obscurity. They are indeed seen to produce seeds (or spores) in great abundance, but the doubtful question is, how these reach the place where they are to grow, whether from the surface of the leaf, to which it is objected that the stomata arc too small to admit them, or, as Mr. Berkeley thinks, from within the plant. Sec POTATO DISEASE.