874 



ORDER VIII. MYXOBACTERALES 



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.) 



