FAMILY SORAXGIACEAE 



1023 



cells. Fail to grow on nutrient agar, 

 washed agar, potato, carrot, milk. 



Source: Isolated from soil. 



Habitat: Soil. Decomposes organic 

 matter. 



4. Sorangium spumostun Krzemie- 

 niewski and Krzemienewska. (Acta Soc. 

 Bot. Poloniae, 5, 1927, 97.) 



Etymology : Latin spumosus, frothy or 

 foamy. 



Swarm stage (pseudoplasmodium) : 

 Rods 0.7 to 0.9 by 2.6 to 5.2 microns. 



Fruiting bodies : Consist of numerous 

 cysts, spherical or oval, not surrounded 

 by a common membrane, but united into 

 bodies embedded in slime. Often in 

 double or single rows. Cyst walls color- 

 less, 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 and habitat: Krzemieniewski 

 (1927, loc. cit.) from Polish soil, isolated 

 on rabbit dung. 



Illustrations: Krzemieniewski (1927, 

 loc. cit.) PI. V, Fig. 19. 



5. Sorangium septatum (Thaxter) Jahn. 

 {Polyangium septatum Thaxter, Bot. 

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

 botanischen Protistologie. I. Die Poly- 

 angiden, Geb. Borntraeger, Leipzig, 

 1924, 75.) 



Etymology: Latin saeptatus, fenced, 

 i.e., divided by walls. 



Swarm stage (pseudoplasmodium) : 

 Rods 0.8 to 1 by 3 to 5 microns. 



Fruiting bodies : Yellowish-orange. 

 When dried, dark orange-red, 50 microns 

 to more than 100 microns in diameter, 

 cysts rounded or ovoid, angular or 

 cylindrical, inner portion of the envelope 

 divided into a variable number of 

 secondary cysts. Cysts 18 to 22 by 12 

 to 22 microns in diameter. Secondary 

 cysts 10 to 12 microns. The Krzemie- 

 niewskis (1927, loc. cit., 96) recognize a 

 variety, Sorangium septatum var. micro- 



cystum, which has secondary cysts with 

 dimensions 4 to 10 by 3 to 8 microns. 



Source and habitat : Collected twice 

 (Thaxter, Bot. Gaz., 37, 1904, 412) on 

 horse dung in Cambridge, Mass. Re- 

 ported by Krzemieniewski (Acta Soc. 

 Bot. Poloniae, 5, 1927) as common in 

 Polish soil. 



Illustrations : Thaxter {loc. cit.) PI. 27, 

 Figs. 25-28. Jahn, Kryptogamen-flora d. 

 Mark Brandenburg, V, Pilze I. Lief 2, 

 1911, 202, Fig. 2. Krzemieniewski, Acta 

 Soc. Bot. Pol., J!^, 1926, PI. 27, Figs. 27-38; 

 ibid., 1927, PI. V, Fig. 15, var. micro- 

 cystum. Fig. 16. 



6. Sorangium compositvun (Thaxter) 

 Jahn. {Polyangium compositum Thax- 

 ter, Bot. Gaz., 37, 1904, 413; Jahn, 

 Beitrage zur botanische Protistologie. I. 

 Die Polyangiden, Geb. Borntraeger, 

 Leipzig, 1924, 74; Polyangium sorediatum 

 Quehl, Cent. f. Bakt., II Abt., 16, 1906, 

 17; not Polyangium sorediatum Thaxter, 

 ibid.) 



Etymology : Latin composilus, com- 

 pound. 



Swarm stage (pseudoplasmodium) :Xot 

 described. 



Fruiting bodies : Dull yellowish-orange 

 changing to dark red on drjnng. Round- 

 ed, small, 0.5 to 1 mm, usually as a whole 

 or even in larger clumps surrounded by a 

 delicate and evanescent membrane. In 

 large fruiting bodies the cysts are bound 

 together in balls 70 to 90 microns in 

 diameter by a delicate membrane. The 

 balls readily fall apart. Secondary cysts 

 are angular, 7 by 11 microns, surrounded 

 by a delicate orange-red membrane, 

 about 0.4 micron in thickness. Length 

 of rods in the cysts 5 microns. 



Source and habitat: Thaxter {loc. cit.) 

 rabbit dung. South Carolina. Jahn (1904, 

 loc. cit.) found it four times on rabbit 

 dung near Berlin, and twice on hare dung 

 in Oberharg. Common in soils of Poland 

 according to Krzemieniewski (1927, loc. 

 cit.). 



