96 
ENDOSPORE^. 
[didymium. 
3. D. Serpula Fries, Syst. Myc, iii., p. 126 (1829). Plasmodium 
lemon-yellow, among dead leaves. Sporangia depressed eff u.sed plas- 
modiocarps, 2 to 8 mm. broad, O'l to 0"15 mm. thick, or perforated 
and net-like, or vermiform, grey ; sporangium-wall membranous, 
colourless, with scattered superficial stellate crystals of lime. 
Columella none. Capillitium of very slender, somewhat branching 
and anastomosing, pale violet threads, connected with numerous 
subglobose vesicles 20 to 50 [x, diam. filled with yellow, obscurely 
granular matter. Spores pale violet-brown, minutely warted, 
7 to 9 /A diam. — E,ost., Mon., App., p. 21. Lycoperdon compla- 
natum Batsch, Elench. Fung., Cont. i., p. 251 (1786). Didymium 
complanatiom Rost., Mon., p. 151 ; Cooke, Myx. Brit., p. 30. 
Plate XXXVIII., A. — a. plasmodiocarp, x 2 ; b. section of the same, 
showing the capillitium and large vesicles, x SO ; e. capillitium and spores, 
X 280 ; d. spore, x 600 (England). 
The drawing of the capillitium in Mr. Massee's Monograph (fig. 56) 
does not represent the characteristic vesicles of D. Serpula, and the 
specimens from Kew, Batheaston, and Carlisle quoted by him (p. 234) 
are plasmodiocarp forms of D. effusuvi, which D, Serpula superficially 
resembles. These vesicles are frequently traversed by the capillitium 
threads, and are apparently formed later ; they are minutely warted, 
hke the spores. 
Hah, On dead leaves. — Lyme Regis (L:B,M.73) ; Freiburg, Ger- 
many (L:B.M.73) ; Germany (B. M. 534, Strassb. Herb.) ; America 
(L:B.M. 73). 
4. D. Clavus Eost., Mon., p. 153 (1875). Plasmodium grey. 
Total height 0*4 to 0'8 mm. Sporangium disc-shaped on a central 
stalk, erect, scattered, 0'7 to 1 mm. diam., 0*2 mm. thick, greyish- 
white ; sporangium -wall membranous, more or less spotted with 
reddish-brown above, and beset with superficial clusters of stellate 
crystals of lime, thicker and brown at the base. Stalk cylindrical, 
longitudinally striate, pale brown or black. Columella none, 
or represented only by the thickened base of the sporangium. 
Capillitium profuse, of sparingly branched colourless or purple- 
brown threads. Spores pale violet-brown, almost smooth, 6 to 8 
/X. diam.— Cooke, Mjx. Brit., p. 30; Mass., Mon., p. 230; Blytt, 
Bidr. K. Norg., Sop. iii. (1892), p. 6. Physarum Clavus Alb. & 
Schw., Consp. Fung., No. 267 (1805). Didymium melanopus fB 
Clavus Fr., Syst. Myc, iii., p. 114. Didymium neglectum Mass., 
Mon., p. 231. Didymium commutabile Berk. & Br., in Journ. 
Linn. Soc., xiv., p. 83; Eost., Mon., App., p. 21. Didymium 
radiatum Mass., Mon., p. 229 (in part). 
Plate XXXVIII., B. — a. sporangia, x 20 ; b. capillitium attached above 
and below to the sporangium- walls, with spores, x 280; c. spore, x 600 
(England). 
The characters of the type specimen of D. commutabile Berk. & Br. 
(B. M. 537) agree in all respects with those of D. Clavus, except that 
the stalk is 1'5 mm. long, and is encrusted with deposits of lime. The 
type of D. neglectum Mass., from Philadelphia, growing with Physa- 
rella mirahilis in Herb. Massee, is a slender form of D. Clavus : in all 
