70 ENDOSPOREAE [PHYSARUM 



of it and then clavate or shortly conical, sometimes absent. 

 Lime-knots either united to form a massive columella giving 

 off horizontal spike-like points which end in simple or forked 

 hyaline threads uniting with the sporangium-wall, or in the 

 spherical sporangia branched and forming an almost Badhamia- 

 like network with few connecting threads. Spores violet- 

 brown, closely spinulose, 10-13 yu, diam. — Petch I.e., 336. 



PI. 76. — a. b. sporangia of various shapes ; some sporangia in 6. have no columella 

 (Ceylon) ; c. sporangium with spores dispersed showing columella ; d. apex of 

 columella ; e. capillitium from sporangium without columella ; /. spore. 



In this variable species a single development may show ovoid, 

 globose and reniform sporangia ; the columella may reach and expand 

 into the upper sporangium-wall and the capillitium show scanty 

 fusiform lime-knots, or the columella may be absent and the lime-knots 

 abundant. When spherical sporangia appear alone they closely 

 resemble P. nutans subsp. leucophaeum, but may be distinguished by 

 the laxer net of the capillitium, the more branched lime-knots, and the 

 rather larger spores. 



Hab. On dead wood.— Lisbon (B.M. 2193) ; Ceylon (B.M. 2191) 

 Japan (B.M. 2192) ; Antigua (B.M. slide). 



36. P. compressum Alb. & Schw. Consp.Fung. 97 (1805). 

 Plasmodium white. Total height 1 to 15 mm. Sporangia 

 reniform, or obovoid, compressed, erect, splitting along the ridge 

 remote from the base, stalked, sessile, or forming plasmodio- 

 carps, scattered, closely aggregated or confluent, white or 

 grey, rugose or warted ; sporangium-wall membranous, 

 colourless or purplish below, including dense clusters of 

 white lime-granules that appear under a low magnification as 

 thickly-set white spots. Stalk stout, equal, furrowed, black 

 from contained refuse matter, or brownish, or white from 

 deposits of lime in the wall, never with a chalk-white fracture 

 at the base. Columella none. Capillitium a close network, 

 with numerous rounded white lime-knots varying in shape 

 and size, connected by rather short seldom branching 

 hyaline threads. Spores dark purplish-brown, more or less 

 spinulose or echinulate, 9 to 14 /x diam. — Sacc. Syll., vii. 

 337. P. griseum Link in Mag. Ges. Nat. Fr. Berl., hi. 27 

 (1809) ? P. nephroideum Rost. Mon., p. 93, figs. 80 to 82; 

 Mass. Mon., 285 ; Macbr. N. Am. Slime-Moulds, 41, in part. 

 P. candidum Rost. I.e., p. 96. P. afjine Rost. I.e., App. p. 5. 

 P. lividum var. conglobatum Rost. I.e., p. 95, in part. P. 

 Phillipsii Balf. fil. in Grew, x. 116 (1882). P. glaucum Mass. 

 I.e., 284. Didymium glaucum Phill. in Grev., v. 114 (1876). 



PI. 39. — a. sporangia of various shapes developed from the same Plasmodium 

 (Hertfordshire) ; b. capillitium and spores ; c. spore. 



PI. 40. — a. sporangia from the type of P. Phillipsii ; b. capillitium and spores. 



The sporangia of this abundant species vary extremely in shape and 

 general appearance. In some forms they resemble those of the following 

 allied species, from which they may be distinguished by the following 



