208 BOTANICAL GAZETTE [SEPTEMBER 
described in Lepiota cristata and L. seminuda (10), in species of 
Cortinarius (14), and in Rozites gongylophora (22). 
In further stages of development, the hyphae in the stem funda- 
ment, by interstitial growth, form a compact, broadly conical area, 
whose apex is the dark-stained region and whose sides in median 
longitudinal sections slope outward at a strong angle (fig. 8). The 
hyphae pursue a rather uniformly longitudinal direction of growth, 
and are rich in protoplasm; the peripheral threads, because of this 
longitudinal arrangement and their deeply staining qualities, 
delimit the surface of the stem from the enveloping ground tissue, 
whose hyphae are poor in protoplasmic content and without definite 
direction. 
DIFFERENTIATION OF HYMENOPHORE AND PILEUS PRIMORDIA.— 
During an early stage in the differentiation of the stem fundament 
there appears, in median longitudinal sections, in the ground tissue 
on either side of the apical part of the fundament, a small mass of 
hyphae, which is readily distinguishable from the surrounding tissue 
because of the compact nature of the hyphal complex and its 
property of taking a deep stain (figs. 4, 7). Serial longitudinal 
sections show that these hyphae occur in a ring around the apex 
_of the stem primordium; they are the earliest evidence of the dif- 
ferentiation of the primordium of the oo The appear- 
ance of th he fundament _ 
one: the pileus from the stem fundament, although as sae the tissue 
composing it is very loose and hardly to be distinguished from the _ 
a — ground tissue. The individual hyphae that make up 
i grow down from this area; at first = 
| | they are crowded, very rich in protoplasm, and run in every direc- 
ee 6). As = 4 
, the — aor out 
nor i mo eve 
