868 



ORDER VIII. MYXOBACTERALES 



Polyangiden. Geb. Borntraeger, Leipzig, 

 1924, 73.) 



so.re.di.a'tum. Gr. noun sorus a heap; 

 M.L. dim. noun soredium a little heap, a 

 soredium; M.L. adj. sorediatus having little 

 heaps. 



Vegetative cells: Rods 0.8 by 3 to 5 mi- 

 crons. Attempts to cultivate have failed. 



Fruiting body: Orange-red, irregularly 

 lobed, consisting of a compact mass of small 

 angular cysts. Average size of cysts, 6 to 7 

 microns; smallest, 3 microns, with thick 

 and sharply defined edges. Rods 0.8 by 3 to 

 5 microns. The Krzemieniewskis (Acta Soc. 

 Bot. Poloniae, 1927, 96) have described a 

 variety, Sorangium sorediatum var. macro- 

 cystum, consisting of cysts 6 to 14 by 7 to 16 

 microns, about twice as large as those in 

 the type species. 



Source: Reported by Thaxter (op. cit., 

 1904, 414) on rabbit dung from South Caro- 

 lina. 



Habitat : Found on decaying organic mat- 

 ter in soil and in the dung of various ani- 

 mals. Common in Polish soils (Krzemieniew- 

 ski, o-p. cit., 1927, 96). 



Illustrations: Thaxter {op. cit., 1904, PI. 

 27, Figs. 22-24), Quehl (Cent. f. Bakt., II 

 Abt., 16, 1906, 9, PI. 1, Fig. 2), Jahn (Kryp- 

 togamen-fiora d. Mark Brandenburg, V, 

 Pilze I, Lief 2, 1911, 202, Fig. 1) and Krze- 

 mieniewski (Acta Soc. Bot. Pol., 4, 1926, 

 PI. IV, Figs. 39-41; also see ibid., 1927, PI. V, 

 Fig. 17, var. macrocystum, Fig. 18). 



3. Sorangium cellulosum Imsenecki 

 and Solntzeva, 1937. (Microbiologia, 6, 

 1937, 7.) 



cel.lu.lo'sum. M.L. noun cellulosum cel- 

 lulose. 



Vegetative cells: Flexible and rod-shaped 

 with rounded ends, 0.4 to 0.6 by 2.2 to 4.5 

 microns, occurring singly. 



Fruiting body: Mature fruiting body 

 rusty brown, 400 to 500 microns in diameter, 

 sessile on layer of partially dried slime. No 

 outer wall or limiting membrane. Composed 

 of numerous cysts, irregular in shape, 1.6 

 to 3.2 microns in diameter, each containing 

 less than ten shortened rods. No discernible 

 cyst wall or membrane. 



Resting cells: 0.3 by 1.5 to 2.0 microns (no 

 other data). 



Vegetative colony: No data. 



Physiology: Good growth on starch and 

 cellulose. Decomposes up to 24 per cent 

 cellulose in ten days but does not form 

 fruiting bodies. Very poor growth on arabi- 

 nose with the formation of many involution 

 forms including very much elongated cells. 

 Fails to grow on nutrient agar, washed agar, 

 potato, carrot or milk. 



Source: Isolated from soil. 



Habitat: Soil. Decomposes organic 

 matter. 



4. Sorangium spumosum Krzemien- 

 iewski and Krzemieniewska, 1927. (Acta 

 Soc. Bot. Poloniae, 5, 1927, 97.) 



spu.mo'sum. L. adj. spumosus foamy or 

 frothy. 



Vegetative cells: Rods 0.7 to 0.9 by 2.6 

 to 5.2 microns. 



Fruiting bodies: Consist of numerous 

 cj'sts, spherical or ellipsoidal, not sur- 

 rounded b}^ a common membrane but united 

 into bodies embedded in slime. Often in 

 double or single rows. Cyst walls colorless, 

 or slightly brownish, transparent, so that 

 the characteristic arrangement of the rods 

 may be seen within. Cysts 8 to 26 by 7 to 20 

 microns. 



Source: From Polish soil; also isolated 

 from rabbit dung. 



Habitat : Found on decaying organic mat- 

 ter in soil and in the dung of various ani- 

 mals. 



Illustrations: Krzemieniewski (ibid., PI. 

 V, Fig. 19). 



5. Sorangium septatum (Thaxter, 1904) 

 Jahn, 1924. (Polyangium septatum Thaxter, 

 Bot. Gaz., 37, 1904, 412; Jahn, Beitrage zur 

 bot. Protistologie. I, Die Polyangiden, Geb. 

 Borntraeger, Leipzig, 1924, 75.) 



sep.ta'tum. L. adj. septatus fenced, i.e., 

 divided by walls. 



Vegetative cells: Rods 0.8 to 1.0 by 3.0 

 to 5.0 microns. 



limiting bodies: Yellowish orange. When 

 dried, dark orange-red, 50 microns to more 

 than 100 microns in diameter, cysts rounded 

 or ellipsoidal, angular or cylindrical, inner 

 portion of the envelope divided into a var- 

 iable number of secondary cysts. Cysts 18 

 to 22 by 12 to 22 microns in diameter. Sec- 



