54 
KNDOSPORE^. 
[PHYSARUM, 
12 to 15 n, and are strongly spinulose ; while in others they are 
smoother, and average 9 to Jl diam. The lime-granules in the 
sporanginm-wall frequently coalesce into vitreous superficial scales or 
coarse particles, and those in the lime-knots become transparent and 
lose their granular character. This feature is occasionally, though 
rarely, met with in other species. In preparations in water of highly 
calcareous sporangia part of the lime is found to dissolve, and on 
drying to crystallise on the slide in particles resembling those described. 
A cultivation from an extensive growth of Plasmodium exhibited 
the forms a, ft, and y in the development of the sporangia. 
a. Sporangia ovoid or reniform, laterally compressed, on short 
black or grey stalks, or sessile. 
^. Sporangia ovoid or reniform, on wliite stalks 0'5 mm, long. 
y. Plasmodiocarps lobed and confluent. 
8. Sporangia subglobose, stipitate. 
Plate XVI., A. — a. sporangia of vars. a, |3, and y, developed from the same 
Plasmodium, x 20 ; b. capillitium and spores, x 280 ; e. spore, x 600 
(England). 
B. — a. sporangia of vars. a and y, drawn from the type specimen of Phy- 
sarum Ph illipsii, x 20 ; h. capillitium and spores, x 280 (England) ; c. 
sporangia of var. 5, x 20 ; cl. capillitium and spores, x 280 ; c. spores, 
X GOO (Iowa, B.M. 807). 
Plate XVII., K.—a. sporangia from type of P. nicaraguense Macb., x 20 ; 
capillitium and spores, x 280; c. spore, x 600 (Nicaragua). 
The specimens named P. nepTiroideum Rost. (Strassb. Herb.) are the 
form a. The type of P. canclidum Rost., from Juan Fernandez 
(K. 510), is the form /3 ; in some of the sporangia the lime-knots coalesce 
to form a central mass ; that of P. Phillij^sii Balf., from Phillips' 
Herb., shows the forms a and y ; and that of P. Uvidum var. conglobatum 
Rost., from Ceylon, No. 55 (K. 1244), is the form a with short black 
stalks ; that of P. affine Rost., from Cuba, No. 907 (K. 1350), is the 
form /3 with white stalks. Didymium hotryoides Berk, in Herb., from 
New Zealand (K. 1523) — a type of D. radiatiim Mass. — is the form a. 
D. 2yrui>iosum Berk. & Curt., from Cuba (K. 1515), given by Rostafinski 
as a synonym for P. 9ie2)hroideuni (Rost., App., p. 5), is the form a. P. 
glaucuiii Phill., in Phillips' Herb., is form a both with short black stalks 
and sessile. In Berkeley's Herb, there are two gatherings from Ceylon 
of one species under the name of P. nutans : one of these (K. 1406) 
is the type of Tilmadoclie reniformis Mass., the other (K. 1407) the type 
of Didymium echi7wspora Mass. It is a form with compressed reniform 
sporangia on long bufE stalks ; capillitium with large fusiform or 
branching lime-knots and short connecting hyaline threads ; spores 
dark purple-brown, spinose, 13 to 15 /x. It appears to be a variety 
of P. eompressum, form a, differing from the type in the long slender 
stalk. 
American specimens, with nearly globose sporangia, and buff or 
white, long or short, stout stalks, from Professors Farlow and Macbride, 
appear from the capillitium and spores to be P. eompressum, but a well- 
marked variety. 'They are more symmetrical than European forms, 
and are distinguished as var. 5. 
The specimen from Nicaragua named P. Jiicaraf/uensc Macbride 
(figured on Plate XVII., A.) corresponds with a long-stalked and 
lobed form of P. eompressum from Ceylon (B. M. 420), part of which 
gathering is shortly stalked or sessile ; it also approaches a specimen 
from Luton (L:B.M.30), iu which the lobed and confluent sporangia 
