258 BOTANICAL GAZETTE [OCTOBER 
rating into floccose patches on the surface of the pileus as in Roziles 
caperata (Pers.) Karsten (Pholiota caperata Pers.). 
During the later period of growth and the beginning of elongation 
of the plant, the marginal veil increases in thickness and extent. It 
_is entirely free from the lamellae, the hymenial cavity being quite 
distinct from the first and becoming greater by the expansion of the 
pileus and marginal veil, and also by the elongation of the portion 
of the stem above its attachment. The increase in the surface extent 
of the marginal veil is considerable and results in throwing the uppet 
surface into radiate folds which are quite noticeable, especially in 
the well developed individuals. In the young primordium at the 
time of the organization of the parts of the carpophore the marginal 
veil is attached over a large part of the outer surface of the stem 
primordium, the lower end, perhaps that portion which corresponds 
to the bulb in other species, being free. It thus remains attached 
over the stem surface for a considerable period during growth, 4s 
the period of elongation advances, the veil begins to separate from 
the stem at the lower end and is gradually torn off and upward as 
the pileus expands and the stem elongates. The tension of the con- 
necting fibers can very easily be seen between the stem and the under 
surface of the veil, and is well shown in fig. 20. It therefore forms 
a sheath over the stem except a short section of the lower end, and 
the portion above the marginal veil which is elongating. 1 
sheath is loosened from below upward except at the upper point at 
attachment to the stem. The outer margin of the veil is attached 
to the rounded and thick margin of the pileus, and being of consider- 
able thickness in these cultivated forms the lower edge of the veil 15 
separated first from the outer surface of the pileus margin (fig. e 
and the inner upper edge is separated last from the inner surface 0 
the pileus margin. The margin of the veil is therefore furrowed (figs. 
18, 19). A thick marginal veil of this type is called a “ double veil, 
a type which is very characteristic of certain other species of Agaricus 
where it is more highly developed, especially in Agaricus _ 
where the lower portion of the veil splits radially. It is very stl le 
in Agaricus rodmani Pk., where the forking of the veil extends coma 
to the stem.*° In Agaricus placomyces Pk. the veil is often similar to 
26 See jig. 17, ATKINSON, Studies of American fungi, mushrooms, edible, poiso™” 
ous, etc. 1900, Igor, Ithaca; 1903, New York. 
