50 ENDOSPORE^. [PHTSAKUM. 



parent, with innate scattered clusters of pale yellow or yeUowish- 

 grey lime-granules ; rupturing when mature into from two to 

 four segments. Stalk erect or curved, 0-5 to 2 mm. high, slender, 

 subulate, translucent, dull 'red or golden red. Columella formed 

 by a continuation of the stalk, penetrating the sporangium to about 

 four-fifths its height, slender, scarcely tapering to the wedge- 

 shaped end, reddish-yellow. Oapillitium a close network of hyaline 

 threads with triangular expansions at the axils of the branches, 

 arising from the whole length of the columella, persistent after 

 the dispersion of the spores ; lime-knots scattered, small, rounded, 

 yellow. Spores pale brownish-violet, delicately spinulose, 5 to 6-5 

 fj. diam. 



Plate XIV., A. — a. sporangia, ellipsoid form, x 20 ; J. sporangia, globose 

 form, X 20 ; c. apex of stalk bearing the columella and capillitium, x 100; 

 d. capillitium and spores, x 280 ; e. spore, x 600 (United States). 



An immature specinien of this species occurs in the Strassburg 

 collection named by Rostaflnski " Craterium leucocepJialum unreif." 

 It agrees in all respects with the American type of P. penetraU, and 

 is interesting as being apparently the only European gathering. 



Hah. On dead wood and moss. — Germany (Strassb. Herb.) ; Phila- 

 delphia (L:B.M.27) 



19. P. nutans Pers., in CTsteri, Ann. Bot., xv., p. 6 (1795). Plas- 

 modium watery white or yellowish-grey from the presence of foreign 

 matter. Total height 1 to 1'5 mm. Sporangia subglobose, more 

 or less flattened or concave beneath, 0*4 to 1 mm. broad ; white, 

 greyish-white, or violet-grey ; gregarious, stipitate, sessile, or plas- 

 modiocarps ; sporangium- wall membranous, with innate minute 

 white granules in more or less dense clusters. Stalk subulate, 

 longitudinally wrinkled, cernuous or erect, yellowish, olivaceous 

 or dark, translucent above, sometimes opaque and white from 

 deposits of lime in the wall, the tube of the stalk containing 

 refuse matter but not lime (never with chalk-white fracture at 

 the base as in P. levxiopus). Columella none. Capillitium of 

 colourless threads, either slender, forked and anastomosing with few 

 flat expansions at the axUs and few small white lime-knots, or with 

 broad, often perforated expansions and large lime-knots. Spores 

 clear violet-brown, nearly smooth or minutely spinulose, 8 to 11 

 /x, diam. — Pers., Syn., p. 171 ; Fr., Syst. Myc, iii.,p. 128. Tihna- 

 doche nutcms Ilost., Mon., p. 127 ; Cooke, Myx. Brit., p. 21 ; 

 Mass., Mon., p. 327. PJi/ysa/rum leucophmwm, Fr., Sym. Gast., 

 p. 24 (1818) ; Ex)st., Mon., p. 113, figs. 77, 78, 89 ; Cooke, Myx. 

 Brit., p. 15; Mass., Mon., p. 288. Physarum gracikntwm Fr., 

 Syst. Myc, iii., p. 133 (1829). FUmadoche ffradlenta Host., Mon., 

 p. 129 ; Mass., Mon., p. 330. Physarum granulatvjn Balf., in 

 Grev., vol. X. (1882), p. 115; Mass., Mon., p. 289. Physwrvm 

 Readeri Mass., Mon., p. 282. 



An extremely variable species ; the stalked and plasmodiocarp forms 

 may develop from the same growth of plasmodium. Sporangia may be 

 found with delicate capillitium and few minute lime-knots, associated 

 with others from the same plasmodium with wide expansions at the 



