The Mycetozoa or Myxomycetes are a saprophytic group without chlorophyll, of simple structure and isolated position.
Those Fungi which are saprophytic can only live when supplied with organic compounds of some complexity, which they derive from decomposing animal or vegetable matter.
Such a source is commonly met with among the Fungi, the insectivorous plants, and such of the higher plants as have a saprophytic habit.
It is not sufficient to find bacteria in the rotting tissues, however, nor even to be successful in infecting the plant through an artificial wound, unless very special and critical precautions are taken, and in many of the alleged cases of bacteriosis the saprophytic bacteria in the tissues are to be regarded as merely secondary agents.
The order is well represented in Britain by 18 genera, which include several species of Orchis: Gymnadenia (fragrant orchis), Habenaria (butterfly and frog orchis), Aceras (man orchis), Hermin- ium (musk orchis), Ophrys (bee, spider and fly orchis), Epipactis (Helleborine), Cephalanthera, Neottia (bird's-nest orchis), one of the few saprophytic genera, which have no green leaves, but derive their nourishment from decaying organic matter in the soil, Listens (Tway blade), Spiranthes (lady's tresses), Malaxis (bog-orchis), Liparis (fen-orchis), Corallorhiza (coral root), also a saprophyte, and Cypripedium (lady's slipper), represented by a single species now very rare in limestone districts in the north of England.
P. 865), the agents of the transformation of cellulose into peaty substances are saprophytic fungi and bacterial ferments.
The Perisporiaceae are saprophytic forms, the two chief genera being Aspergillus and Penicillium.
An epiphytic fungus is not necessarily a parasite, however, as many saprophytes (moulds, &c.) germinate and develop a loose mycelium on living leaves, but only enter and destroy the tissues after the leaf has fallen; in some cases, however, these saprophytic epiphytes can do harm by intercepting light and air from the leaf (Fumago, &c.), and such cases make it difficult to draw the line between saprophytism and parasitism.
Notwithstanding the absence of chlorophyll, and the consequent parasitic or saprophytic habit, Bacteriaceae agree in so many morphological features with Cyanophyceae that the affinity can hardly be doubted.
Nearly all bacteria, owing to the absence of chlorophyll, are saprophytic or parasitic forms. Most of them are colourless, but FIG.
Koch in 1876 published his observations on Davaine's bacilli, placed beyond doubt their causal relation to splenic fever, discovered the spores and the saprophytic phase in the life-history of the organism, and cleared up important points in the whole question (figs.
The Sereh disease of the sugar-cane, the slime fluxes of oaks and other trees, are not only very doubtful cases, in which other organisms such as yeasts and fungi play their parts, but it may be regarded as extremely improbable that the bacteria are the primary agents at all; they are doubtless saprophytic forms which have gained access to rotting tissues injured by other agents.
Saprophytic bacteria can readily make their way down the dead hypha of an invading fungus, or into the punctures made by insects, and Aphides have been credited with the bacterial infection of carnations, though more recent researches by Woods go to show the correctness of his conclusion that Aphides alone are responsible for the carnation disease.
All the saprophytic prothalli contain an endophytic fungus in definite layers of their tissue.
Pedunculosum, as observed by Mettenius, subsequently reached the surface and produced green lobes; those of the other species known are wholly saprophytic, and contain an endophytic fungus.
They present a general, but probably homoplastic, resemblance to the saprophytic prothalli of certain Lycopodia.
Nutrition is of course holozoic or saprophytic in the colourless forms, holophytic in the coloured; but these divergent methods are exhibited by different species of the same genus, or even by individuals of one and the same species under different conditions.
Certain species, such as Gymnodinium spirale, are colourless and therefore saprophytic in their method of nutrition.