SPREADING OF DISEASE AND EPIDEMICS. _Dissemination of fungi by the aid of snails, rabbits, bees, and insects--Man--Distribution in soil, on clothes, through the post, etc.--Worms, wind--Puffing of spores--Creeping of mycelia--Lurking parasites--Spread of insects and other animals--Losses due to epidemics._ The dissemination of plant diseases is a subject which has been far too much neglected, but our knowledge of it is slowly increasing. The spores of fungi such as Rusts and Erysipheae are often carried from plant to plant by snails; those of root-destroying and tree-killing Polyporei by rabbits, rats, and other mammals which rub their fur against the hymenophores. Bees have been shown to carry the spores of _Sclerotinia_ and infect the stigmas of Bilberries, etc., with them; and flies convey the conidia of Ergot from grain to grain. Insects, indeed, of all kinds are great disseminators of disease--as witness also the part played by mosquitoes in transferring the malaria parasite to man--and beetles, bees, flies, etc., of all sorts probably play more active parts in this work than has yet been proved, since they not only carry spores attached like pollen to their hairy bodies, but in many cases in their alimentary canal, to be spread later in the dung. The part played by man in conveying fungi from plant to plant counts for much. Not only do gardeners and farm labourers carry spores on their boots and clothes as they pass from infected to non-infected areas, but carted soil and manure are frequently infested with spores of Smuts, _Fusarium_, _Polyporus_, and the sclerotia or rhizomorphs of _Sclerotinia_, _Agaricus melleus_, _Dematophora_, etc. Man also sends diseases through the post, and by rail and ship, by spores or mycelia attached to seedlings, bulbs, fruits, flowers, etc., as shown in several cases of potato, vine, hollyhock, lily, and hyacinth diseases. Every time a carpenter saws a piece of fresh timber with the saw which has been used previously for cutting wood attacked with dry rot, he risks infecting it with the fungus. Similarly in pruning: every cut with a knife which the gardener has used on infected branches may infect the tree. Cuttings made with a soil-contaminated knife and stuck into ordinary soil in dirty boxes covered with equally dirty glass, present every chance for infection by soil organisms; bacteria and fungi obtain access to the vessels, and derive plenty of food from the juices, and the wonder is not that so many cuttings "damp off," but that any are raised at all under ordinary conditions.