Conard: Structure of Simblum Sphaerocephalum 269 
stalk is then the place of attachment of the plate tissue to the 
lowest horizontal bars of the receptaculnm, which has become 
extended into a sheath as the bars elongated to form the stalk. 
The superficial position of the bars of the receptaculnm in the 
head of Simblum sphaerocephalum has already been remarked 
(fig. i). In this it differs markedly from S', periphragmoides 
(Fischer, 1893, 1900, 1901) whose bars are deeply embedded in 
the gleba. On critically examining the relation of gleba to recep- 
taculum, we find in many cases gleba-chambers bounded on one 
side by fertile hymenium and on the other by pseudoparenchyma 
of the receptaculum-arm (figs. 9, 12). The transition from 
hymenium to pseudoparenchyma, however, is not gradual, but 
abrupt. Sometimes a narrow strip of tramal tissue lies between 
them. In many cases it is evident, so far as sections can prove, 
that the tramal hyphae are continuous with the pseudoparenchyma 
(fig. 10). Thus the pseudoparenchyma has a double origin. In- 
deed one frequently finds cavities separating the portions of differ- 
ent origins (fig. 10). These facts support Fischer’s view, pro- 
posed in 1890, and proven for Dictyophora irpicina in 1910 (b), 
that the pseudoparenchyma represents sterile hymenial tissue, or 
a hymenium of paraphyses without basidia. In this case the 
cavities in the pseudoparenchyma of Simblum may be considered 
to be rudimentary gleba-chambers (fig. 10, /). Burt (1894) 
maintained that the pseudoparenchyma of Anthurus borealis is 
of strictly “ cortical ” nature, and has no connection with the 
surrounding gelatinizing hyphae. This idea was apparently 
drawn chiefly from sections in the stalk region, where the tissues 
are much more sharply separated. After the first rudiments of 
the stalk are formed as the lowest mesh of a net-like receptac- 
ulum, according to our theory, the further development of the 
stalk tissues may be quite independent of one another. Thus 
Burt’s observations would be entirely right, and in no contradic- 
tion with Fischer’s (1900) and my own. In one of my plants of 
Simblum two bars of receptaculnm tissue were found near the 
center of the head, completely embedded in the gleba (fig. 6). 
Following these upward, they joined one of the upper bars of 
tbe receptaculnm. Another specimen showed bars of tbe receptac- 
ulum extending deep into the gleba. These irregularities might 
