140 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
and normal basidia are especially well seen in Agaricus ( Mycena) 
rugosus Fr. 
None of these alleged spores reported in species of Pleurotus and 
other agarics have been germinated and grown in cultures, hence 
their functions and importance remain problematical. They are 
evidently of the same type as the spores produced in Stereum hirsutum 
(see p. 135) as the result of unfavorable conditions of growth, especially 
dampness. In the cases described by Eichelbaum the conidiophores 
are evidently modified basidia; in Pleurotus the morphology is less 
clear, although Matruchot and Heckel believe that here also the 
spores are produced by degenerate basidia. 
In his “Text-book of comparative morphology” (p. 334 of Eng. 
transl.) de Bary says: “The slender stipe of Agaricus (Collybia) 
racemosus Pers. is beset throughout its whole length with short hair¬ 
like spreading branches which were compared by Fries (’36, p. 90) 
and Berkeley (’57, p. 365) to the sporophores of the form-genus 
Stilbum, because like them they abjoint at their extremities numerous 
spores (gonidia) arranged in rows and forming together a small gela¬ 
tinous head.” The presence of these spores is confirmed by Stefan 
(’05), who says the sporophores are collected into “ein Stilbum- oder 
Pilacre-ahnliclier Ivopfchen,” which usually bears a water drop. 
The spores are regularly ellipsoidal, and are borne singly or in rows 
on the ends of the hyphae; they germinate readily in culture cells. 
Stefan called these bodies chlamydospores, although they are thin- 
walled, and from his description would seem to be more of the nature 
of oidia. Brefeld (’89, p. 61) found numerous oidia on the mycelium 
of this species, but no chlamydospores or conidia. 
A very interesting conidial form has been described by Oersted 
(’65) as belonging to Agaricus ( Claudopus ) variabilis P. Short, 
non-septate, erect sporophores arise from the mycelium and abjoint 
ellipsoidal spores simultaneously in a small head at their extremities. 
The author compares the conidiophores with Corda’s form-genus 
Cephalosporium. Unfortunately, Oersted did not prove the connec¬ 
tion of the Cephalosporium with Agaricus variabilis by culture study. 
Brefeld obtained only sterile mycelia in his cultivation of this species. 
Hence it seems probable that the Cephalosporium is a parasite on the 
mycelium of the Basidiomycete, an interpretation which is strength¬ 
ened by the presence of certain large cells and adjacent slender 
branches, organs regarded by Oersted as oospheres and antheridia 
respectively, but which give the appearance of parasitism. 
