1917] SAW YER—PHOLIOTA 217 
formation in the preceding species. The ground tissue is loose from 
a very early stage, and through expansion of the different parts of 
the fruit body it becomes torn away from the lower surface of the 
hymenophore. This separation from the hymenophore is com- 
pleted at an earlier stage than in P. squarrosa, and consequently 
a well defined cavity is present before the origin of the lamellae 
(figs. 34, 37). 
During the development of the hymenophore primordium and 
the breaking away of the ground tissue below hyphae are growing 
down from the pileus margin. These threads penetrate the ground 
tissue below the prelamellar cavity and mingle with those on the 
surface of the stem. In fig. 33 they may be seen curving inward 
from the pileus margin. In the stage represented here they have 
not yet reached the surface of the stem, and the loose ground tissue 
surrounding the latter may still be seen between it and the advan- 
cing hyphae from the pileus margin. These threads are sharply 
contrasted with the other tissue of the basidiocarp because of their 
Shs Salon, Which i tee aie nin ead os can ‘ 
addition, they may be distinguished from the blematogen external 
to them by their deeper stain. These hyphae from the pileus — 
, together with the ground tissue below the hymeno- 
-phore, form the pattinl veil; it tears away from the stem at an 
early stage in the expansion of the plant, and may in some 
ee iculate 
veil. — 
: Onions AND DEVELOPMENT OF oe ola ad ae 
i 
the conditi P. squarrosa. Here we have ._ 
