GASTEROMYCETES 487 



In Hydnangium carneum, which alone has been cytologically investi- 

 gated (Ruhland, 1901; Petri, 1902; Bambeke, 1904), there are extensive 

 irregularities in the development of the basidium, which sometimes 

 forms only one spore, into which occasionally all four nuclei migrate. 

 As far as is known, an early division occurs in the normally developing 

 spores, as is usual in most Gasteromycetes. 



Stephanospora carotaecolor differs from Hydnangium only in having 

 a conspicuous collar at the base of the basidiospore. 



In an unidentified species, tentatively placed in Hydnangium by E. 

 Fischer (1925), development is gymnocarpous at first and similar to that 

 in Elasmomyces, but eventually the columella is obliterated by the for- 

 mation of new cavities suggestive of those in Chamonixia and Gallacea. 



In Arcangeliella, a columella penetrates the gleba branching into 

 tramal plates, as in Elasmomyces, but distinguished from it by the 

 presence of latex ducts similar to those of Lactarius, and by slightly differ- 

 ent spore markings. In A. caudata, the peridium is thin, with the outer 

 hyphae perpendicular to the surface of the fructification. The cells of 

 these hyphae break apart easily as oidia, but it is unknown whether 

 they are capable of germination (Zeller and C. W. Dodge, 1919). In 

 the cosmopolitan Arcangeliella Stephensii {Hydnangium Stephensii) 

 E. Fischer (1925) reports the development similar to that of Elasmomy- 

 ces. In A. violacea (Hymenogaster violaceus) the peridium becomes 

 viscid, as in some species of Hymenogaster, and the spores are more 

 ellipsoidal. 



The highest member of the series is Maccagna, where the tramal 

 plates are differentiated into two kinds: the thick primary branches of 

 the forked columella, composed of varicose hyphae and abundant latex 

 ducts, and the secondary branches of tramal tissue composed of slender, 

 compact hyphae without latex. Neither M . carnica nor M. tasmanica 

 has been studied carefully, but the structure of the mature plant is sug- 

 gestive of conditions we shall meet again in Phallogaster. 



The main line of development proceeds through Elasmomyces, which 

 lacks the latex organs of the Arcangeliella — Maccagna series. In Elasmo- 

 myces krjukowensis (Secotium krjukowense) the fructifications are devel- 

 oped gymnocarpously (Bucholtz, 1901); the columella is percurrent and 

 continuous with the peridium at the top. The peridium (pileus, of 

 some authors) rolls in toward the bottom without being connected to the 

 stipe; a few of its hyphae, however, may intertwine with the stipe hyphae, 

 but the line between the two tissues may be easily recognized. Both 

 peridium and stipe are composed of strands of slender hyphae and nests 

 of pseudoparenchyma similar to the structures found in the Lactariaceae. 



The tramal plates grow further from the pileus toward the interior 

 of the cavity, intertwine at their tips with hyphae from the columella 

 and form numerous folds which anastomose with each other. This 



