1917] SAWYER—PHOLIOTA 221 
with some hyphae which grow down from the pileus margin. This 
growth, however, is not as strong as in P. flammans. The partial 
veil is covered externally by the blematogen. It ruptures at the 
pileus margin during expansion of the plant, leaving a thin and 
fugacious annulus on the stem. 
_ ORIGIN AND DEVELOPMENT OF LAMELLAE.—The origin and 
growth of the gills take place in this species much as in P. flammans. 
The first evidence of the origin of the gill salients is the downward 
projection of the palisade layer in broad folds (figs. 50, 51). A 
single one of these broad folds includes several of the tufts which 
earlier appear in the hymenophore primordium and become lost 
in the palisade; consequently, these tufts cannot be considered as 
gill fundaments or directly concerned in their origin. At the apex 
of the folds the ends of the palisade cells may in some cases spread 
slightly apart, showing that considerable pressure is exerted by the 
downward growing hyphae from the hymenophore above. Under 
no circumstances, however, do the gill salients show any evidence 
of splitting; the hyphae merely spread slightly apart at the ends, 
and in later stages come together again to form an uninterrupted 
palisade. Serial sections show that the formation of the gill 
salients is radial and centrifugal. 
‘Figs. 53, 54, and 55 show a condition that might easily lead to z a ee 
wrong interpretation of the origin of the lamellae by one not 
familiar with the orientation of the parts involved. A simi 
condition existing in Agaricus rodmani has been explained by 
ATKINSON (8) and so will not be gone into in detail here. Te 
sections are tangential in the margin of the pileus at a stage in Es 
development when the pileus margin isenrolled. The attachment — 
of the gill trama both above and below does not mean that the : 
__ trama of the gill has grown down and pe as ee = oF 
a as fie’ appear at “first glance. The pileus margin : 
