40 
ENDOSPOREy*;. 
[I'llYSAllUM. 
which <are 10 to 50 broad and tilled wiili globular lirue-granuie.s, 
1 to 1'5 /X diam. Sj^ores violet-brown, minutely spinulose, 7 to lU 
fjb diam. — Rost., Mon., p. 101; Cooke, Myx. Brit., p. 12 ; Mass., 
Mon., p. 287 (in part) ; Macbride, in Bull. Nat. Hist, Iowa, ii., 
p. 156. Didymium leucopus Fr., Syst. Myc., iti., p. 121. 
Plate VI., A. — a. sporangia, x 20 ; h, capillitium with fiagment of spo 
rangium-wall and spores, x 280 ; c. spore, x 600 (England). 
The snow-white nearly smooth stalk, which is chalk-white in section 
to the base, always distinguishes P. leucopus from P. nutans. Tlie 
lax capillitium, with large lime-knots and the large lime-granules 
in the knots and sporangium-wall, separate it from P. globuliferum, 
which is its nearest ally. The types quoted by Rostafinski from 
Germany and Russia of this well-marked species are not represented 
in the Strassburg or British collections ; the stations here given are 
therefore confined to those of the English and American gatherings. 
It is not common ; the only specimen in the Kew collection (K. 518), 
leg. J. Henderson, is named Didymium squamulosum. 
Sab. On dead leaves, moss, etc. — Batheaston, Somerset (B.M. 48) ; 
Lyme Regis, Dorset (L:B.M.ll) ; Ohio (L:B.M.ll) ; New Granada 
(Paris Herb.). 
2. P. globuliferum Pers., Syn., p. 175 (1801). Plasmodium ? 
Total height 1 to 1"5 mm. Sporangia globose, stipitate, erect, 
white, gregarious, 0"5 mm. diam. ; sporangium-wall membranous, 
with crowded clusters of innate lime-granules. Stalk white or 
pale bufF, sometimes red- brown towards the base, 0-5 to 1 mm. 
long, "05 to "01 mm. thick, nearly smooth, brittle, chalky in section. 
Columella conical. Capillitium persistent, retaining the form of 
the sporangium after the dispersion of the spores, forming a close 
network of obtusely branching hyaline threads with numerous 
fusiform or rounded, white, or pale ochraceous lime-knots 10 to 
20 fji diam. ; the lime-knots are not usually developed at the 
axils of the branches, which are flat and triangular, or if 
present, usually minute. Spores violet-brown, almost smooth, 
6 to 8 /A diam. Host., Mon., p. 98, fig. 86 ; Mass., Mon., p. 297. 
Sphcurocmyus glohuliferus Bull., Champ., p. 134, Fl. 484, fig. 3 
(1791). PhysaruTii Petersii Berk. & Curt., var. a. Farloioii Eost., 
Mon., App., p. 6. Physarv-m albicans Peck, in Rep. New York 
Mus., xxx., p. 50; Mass., Mon., p. 312. Didymium Barteri 
Mass., Mon., p. 231. Physarum coluinlinum Macbride, in Bull. 
Nat. Hist. Iowa, ii., p. 384. 
Plate VI., B.— a. sporangia, x 20, in two the sporangium-wall has fallen 
away, leaving the persistent head of capillitiiira ; b. stalks showing the 
columella after the capillitium has broken away, x 20 ; c. capillitium, 
columella, and spores, x 280; d. spore, x 600 (United States). 
The types of P. Petersii var. a Farlowii Rost., and P. albicans Peck 
are the same species as the type of P. globuliferum in the Strassburg 
collection. P. coluinbinum Macbride, from Iowa (B.M. 1012), is also 
P. globuliferum ; it has snow-white, occasionally red-brown, stalks, 
and well-developed conical columella). Didynuum, Barteri Ma.s». (K. 74) 
appears to have been rightly named by Rostafinski " /•*. glohuliferunt, 
iminaturum" ; the specimen is obscured by mould. In the specimen 
