_Damping off._--When seedlings are too closely crowded in beds kept too damp, or in moist weather, they are very apt to rot away, with all the symptoms--spreading from a centre, contagious infection, mycelia on and in the tissues, etc.--of a fungus attack. The commonest agent concerned is one of the species of _Pythium_, the propagation of which is favoured by the rank, over-turgid, and etiolated conditions of the plants. Species of _Mucor_, _Botrytis_, and other fungi, may also be met with. _Bursting_ of fleshy fruits, such as Tomatoes, Grapes, etc., is due to over-turgescence in rainy weather or excessively moist air. But the phenomenon is by no means confined to such organs. Hot-house plants when oedematous not infrequently put out watery blisters from the cortex or leaves, which rupture; and the stems of fleshy fasciated (_e.g._ Asparagus) or blanched and forced plants (_e.g._ Celery, Rhubarb) are particularly apt to crack here and there from the pressure of the turgescent tissues on the strained epidermis. Beets, Turnips, and other fleshy roots show the same phenomena in wet seasons. That these ruptures and exposures of watery tissues afford dangerous points of entry for parasites and moulds will be obvious--_e.g._ _Edelfäule_, a rotten condition of the grapes in the Moselle district. _Root-rot_ is a common disease in damp, sour clay soils after a continuance of wet weather--_e.g._ Wheat, especially if root-drawn and exposed to thaw water. In the disease known as Beet-rot, the roots turn black at the tip, where the tissues shrivel and become grooved and wrinkled extensively. Inside the flesh also blackens and finally rots. In earlier stages, only the vascular bundles are brown and blocked with gum-like substances. In advanced stages there is much gummy material in the lumina, and even large cavities filled with this gum may be found. The rot of Cherries, Pears, Apples, Plums, etc., in store may be due to several fungi, of which _Botrytis_, _Monilia_, _Mucor_, _Penicillium_, and _Aspergillus_ are the chief. The fruit may be attacked while still on the tree, but very often fungi and bacteria gain access to the tissues, through bruises, cracks, etc., formed in the fruit lying in the storage baskets or on the shelves. Rot in Onions, Hyacinth bulbs, etc., is frequently due to the access of _Botrytis_ or _Sclerotinia_, followed by moulds, yeasts, and bacteria in the stores. _Sour-rot_ in Grapes, and other fleshy fruits which need much sun to ripen them, is probably a usual result of continued cold, wet weather at the cropping season, setting in when the fruits are beginning to swell.