326 
GERTRUDE E. DOUGLAS 
outside of the stem, they are slender and dense, forming a very firm 
outer supporting layer. 
CORTINARIUS CINNAMOMEUS 
(Figs. 25-50) 
Early Stages of Development. — Cortinarius cinnamomeus develops 
in a manner very similar to that of C. anfractus, although there is 
considerable difference in the appearance of their tissues, that of this 
species being more dense in its character than that of the preceding. 
The earliest stage examined is represented by figure 25, from a section 
of a button about 2 mm. X i mm. in size. This has already differ- 
entiated sufficiently to show a dense dome-shaped fundament of the 
pileus and that of the stem below and it is quite possible that earlier 
stages would show the stem fundament differentiated first as a conical 
area, as described for C. anfractus and for the other species described 
in this paper. The hyphae of the pileus fundament average about 
1.6 )u in diameter but in the lower part of the stem and in the veil 
region they reach two or three times this size. The pileus primordium 
lies very near the surface, leaving only a very narrow thin zone of 
blematogen. The latter is composed of large hyphae with diameters 
of 4 or 5 fjL. They are somewhat interwoven^ and are arranged more 
or less radially over the surface of the pileus, excepting in the hymeno- 
phore region, where they are very nearly parallel to the surface. 
This blematogen layer is retained by the plant until maturity and 
accounts for the fibrillose nature of the surface of the pileus, a dis- 
tinguishing characteristic of the sub-genlis Dermocybe, to which C. 
cinnamomeus belongs. It never separates as a universal veil but is 
partly worn off in the form of scales, as the fruit body pushes through 
the soil (figs. 32, 39, 44). The lost fibrils appear to be continually 
replaced by outgrowths from the surface of the pileus. The marginal 
veil never becomes very strongly developed. It receives new elements 
from the margin of the pileus (figs. 28, 30), but it retains its loose 
floccose nature. The large open mesh provides a very free com- 
munication for air with the outside. 
The Development of the Hymenophore. — Simultaneous with or soon 
after the formation of the pileus fundament takes place, an internal 
annular zone of rapid growth appears at its margin and represents the 
beginning of the hymenophore. This primordial stage is followed by 
