Myxomycetes

Myxomycetes, or MYCETOZOA, a class of very simple organisms, sometimes claimed by botanists as fungi, and by zoologists as primitive Protozoa. They live on damp surfaces exposed to air, especially on rotting wood, and feed on organic debris. They form composite masses or plasmodia, in which numerous units are fused, or in rare cases simply combined in close contact. On the margins of such a mass amoeboid processes of living matter flow in and out, with streaming internal movement, and the plasmodium spreads towards moisture, food, and warmth, or away from the light. Drought, cold, or scarcity of food produce a dormant encysted stage. At other times part of the plasmodium divides into spores, each enclosed in a coat, which bursts and liberates a swarm spore, sometimes flagellate, always eventually like a little amoeba. A number of these minute amoebæ unite to form the plasmodium from which we started. About two hundred species have been described. See FUNGI, PROTOZOA; De Bary, Die Mycetozoen (1864); Zoph, Die Schleimpilze, in Schenk's Botanik, iii. (1887).