66 ENDOSPORE.E. [FULIGO. 



KEY TO THE SPECIES OF FULIGO. 



^Ethalia and lime-knots yellow or variously coloured :- 



Spores nearly smooth, 7 to 10 /x diam. (1) F. septica 



Spores spinulose, 10 to 11 /x diam. (2) F. ochracea 



^jjthalia and lime-knots pure white. (3) F. ellipsospora 



1. F. septica Gmelin, Syst. Nat., p. 1466 (1791). Plasmodium 

 yellow. .^Ethalia pulvinate, varying much in size, from 2 mm. to 

 20 cm., broad, yellow, pinkish or dull white or reddish-brown. 

 The sporangia constituting the sethalium are intricately coiled 

 and anastomosing, 2 to 2 '5 mm. broad, with air spaces in the 

 intervals which permeate the mass. The cortex is sometimes 

 wanting, when the surface is grey and marked with brain-like 

 convolutions. Sporangium-walls within the sethalium membran- 

 ous, very fragile, colourless, with scattered deposits of lime-granules. 

 Columella none. Capillitium very variable, a loose network of 

 slender hyaline threads more or less expanded at the axils, with 

 rounded, fusiform, or branching yellow or whitish lime-knots, 

 varying much in size. Spores violet, almost smooth, 6 to 10 /x 

 diam. Blytt, Bidr. Norg., Sop. iii. (1892), p. 5. Mucor septicus 

 Linn., Sp. PI., Ed. 2, p. 1656 (1763). Fuligo varians Sornm., Fl. 

 Lap., p. 239; Host., Mon., p. 134; Cooke, Myx. Brit., p. 23; 

 Mass., Mon., p. 340; Macbride, in Bull. Nat. Hist. Iowa, ii., p. 160. 

 jEthalium septicum Fr., Syst. Myc., iii., p. 93 ; Cooke, Handbook, 

 No. 1101. Physarum gyrosum Host., Mon., p. 111. Physarum 

 cerebrinum Mass., Mon., p. 306. Licea Lindheimeri Berk., in 

 Grev., ii., p. 68. Tubulina Lindheimeri Mass., Mon., p. 42. 



Plate XXIV., A. a. a small part of an ecorticate setjialium, nearly 

 resembling the type of Physarum gyrosvm Eost., x 20 ; 5. capillitium with 

 fragment of sporangium-wall and spores, x 280; c. spore, x 600 ( England) ; 

 d. capillitium and subellipsoid spores from a corticate asthalium, x 280 

 (Black Forest, Germany). 



Rostafinski's type specimen of Physarum gyrosum Host, from Berlin 

 in the Strassburg collection consists of minute pinkish sethalia of Fuligo 

 septica 2 to 3 mm. broad, without superficial cortex. He quotes 

 Reticularia muscorum Fr. (Syst. Myc., iii., p. 91), as a synonym for 

 P. gyrosum ; it appears probable from Fries' description that his 

 species was also a small ecorticate form of F. septica. In the type 

 specimen of Licea Lindheimeri Berk, from Texas (K. 1648) only the 

 basal part of an aethaliurn remains ; it is an orange form of Fuligo 

 septica with scanty delicate capillitium and violet spores measuring 5 

 to 7 p. The type of Physarum cerebrinum Mass., produced in a hot- 

 house at Kew (K. 195), is also a form of F. septica with no cortex 

 developed over the convoluted sporangia ; it is found that if the rising 

 plasmodium is protected by a bell-glass from currents of dry air, the 

 outer sporangia develop as well as the inner, and no cortex of barren 

 sporangia is formed. 



Hab. On rotten wood, tan, etc. Common. Leytonstone, Essex ; 

 Lyme Regis, Dorset (L:B.M.40) ; Highgate (B. M. 155) ; Europe 

 (B. M. 461, 463) ; South Africa (K. 232) : Australia (B. M. 468) ; 

 New Zealand (K. 201) ; N. America (B. M. 813). 



