THE DEVELOPMENT OF CORTINARIUS PHOLIDEUS 
differentiation of pileus and stem, some ground tissue is left in the 
angle between them. This is nearly all broken away in the process of 
formation of the gill cavity, but a small amount may remain attached 
CO the pileus margin, beneath the blematogen. This is increased by 
the downward growth of a few hyphae from the extreme margin of the 
pileus, and in figures 14 and 15 it is probable that the inner layer of the 
veil described above does not belong entirely to the blematogen, but 
has on its inner surface some hyphae belonging to the marginal veil 
proper, as limited from the universal veil or blematogen. 
The Cortina 
The name "cortina" is a term applied especially in the genus 
Cortinarius to the veil composed of delicate silky fibrils stretching 
from the pileus margin to the stem. It is usually evanescent, although 
in a few species, like C. armillatus, it may persist for a long time in the 
form of rings about the stem. In C. pholideus it breaks away early, 
leaving a very slight ochraceous annulus around the top of the stipe 
that disappears with age. Occasionally a half-grown plant is found 
with the arachnoid veil still intact. It is light in color, almost white, 
and stretched tightly over the gills. The fibers composing it are very 
slender, and this character, together with its lighter color, distinguishes 
the cortina from the brown-walled, larger hyphae of the outer blema- 
togen layer, w^hich is external to the cortina in varying amount, de- 
pending on how much has been rubbed off during the development of 
the plant. The cortina is composed of the hyphae of the inner layer 
of the blematogen, together with whate</er marginal veil may be pres- 
ent. In figures 20 and 21 it may be seen extending from the pileus 
margin to the stem. Outside is tissue belonging to the outer layer of 
the blem.atogen. Figure 22 shows a condition so common as to be 
almost characteristic in this species, in which the pileus margin is so 
strongly inroUed that it has become free from the cortina, which is 
attached to the pileus surface above its margin, thus showing that 
the cortina represents here the inner zone of the duplex blematogen. 
Fries (9) mus.^ have regarded the cortina as a structure distinct 
from the universal veil or blematogen, for, although its presence was 
used by him for a generic character, only two of his six subgenera, 
namely Myxacium and Telamonia, are said to possess a universal veil. 
C. pholideus, however, put by Fries in the sub-genus Inoloma, has a 
universal veil, and the same has been found by Miss Douglas in species 
