Vegetative colony : A faint yellow cast on cellulose-silica gel after 2 to 3 days. Be- comes 3'ellow-orange to yellow-pink after 6 to 8 days, while center is brownish gray. Margin pinkish to yellow-pink. Surface dull, moist. As fruiting bodies ripen, colony be- comes darker, finally dark brown. Reaches diameter of 2 to 5 cm. Fruiting bodies often arranged in form of pigmented, closely set, concentric rings. Margin of colony not clearly defined. Usually regularly rounded or ellipsoidal. Cellulose completely de- stroyed only at center of colony. Source: Found only once in podzol soils. Common in black soils of Sumy Experiment Station. Habitat: Soil. Decomposes cellulose. 5c. Polyangium cellulosum var. Julvum Mishustin, 1938. (Microbiologia, 7, 1938, 427.) ful'vum. L. adj. fulvus reddish yellow. Vegetative cells: 0.8 to 1.2 by 3.5 to 6.0 microns. Fruiting body: Rose or pink in color, composed of numerous cysts. Young cysts yellow to yellow-orange, becoming pink, rose or red, or pinkish yellow. Cysts same shape as others of the species; 6 to 24 mi- crons in diameter, average 10 to 12 mi- crons; contain many short rods. Fruiting bodies vary in shape, often elongated, flagella(?) -shaped (columnar?), up to 20 to 25 by 350 to 450 microns. Also globular, mace-shaped, etc. Usually 25 to 40 by 50 to 80 microns. Cysts enclosed by outer common envelope or slime membrane. Easily broken up mechanically. Vegetative colony: On cellulose -silica gel form a hardly visible white (colorless?) colony at 2 days. After 6 days becomes pink in color. Fruiting bodies first form near center. After 9 to 10 days central area red- dish pink while periphery has yellowish cast. Mature colony 2.5 to 7.5 cm in diame- ter, pink-orange color, fairly regularly round or ellipsoidal in shape. Pigmented concentric rings of fruiting bodies. Physiology: Cellulose entirely destroyed at center of colony and often at other points. Source: Podzol soils of Timiriazev Agri- cultural Academy. Seldom in black soils of Sumy Experiment Station. Habitat: Soil. Decomposes cellulose. 5d. Polyangium cellulosum var. luteum Mishustin, 1938. (Microbiologia, 7, 1938, 427.) lu'te.um. L. adj. luteus saffron-yellow. Vegetative cells: Similar to others of the species. Fruiting body: Poorly organized agglom- erations of colorless to yellow cysts en- closing sporulated cells. Cysts regularly egg-shaped to ellipsoidal, 8 to 20 microns in diameter; predominantly 6 to 10 microns. Matured cysts loosely connected into rounded or elongate masses 40 to 80 by 100 to 150 microns. Ripe fruiting bodies easily pulled apart. Vegetative colony: On cellulose, colonies regularly rounded or ellipsoidal, surface has moist appearance. Yellowish cast 2nd or 3rd day, becoming deeper yellow. Ochre- yellow formations resembling fruiting bod- ies by 5 to 6 days. Manj^ free cysts at center of colony. Later colony becomes pale dirty yellow while periphery remains bright yel- low. Sometimes one or two brightly pig- mented rings consisting of agglomerations of fruiting bodies are found in older colonies. Mature colonies 1.5 to 3.0 cm in diameter. Physiology: Filter paper completely de- stroyed at center of colony. Developed bet- ter below pH 7 (around pH 6) than others of the species. Source: Isolated from soils of the Timiria- zev Agricultural Academy. Common in podzol soils. Habitat: Soil. Decomposes cellulose. 6. Polyangium simplex (Thaxter, 1893) Thaxter, 1904. (Myxobader simplex Thaxter, Bot. Gaz., 18, 1893, 29; Thaxter, ibid., 37, 1904, 414.) sim'plex. L. adj. simplex simple. Vegetative cells: Large, cylindrical rods, rounded at either end, 0.7 to 0.9 by 4.0 to 7.0 microns. Fruiting bodies: Cysts single, very large, 250 to 400 microns, bright reddish yellow, irregularly rounded. Rods flesh-colored in mass. Upon pressure, adhere together in sheaves. Source: Isolated from very wet wood and bark in swamps. 7. Polyangium ochraceum Krzemie- niewski, 1926. (Acta Soc. Bot. Poloniae, 4, 1926, 34.)
