THE DEVELOPMENT OF SOME SPECIES OF AGARICS 
Fig. 61. A slightly oblique cross-section through the pileus margin and stipe, 
showing: (i) primary gills on the stipe; (2) the upper left hand portion of the 
figure shows two "bars" of the primary gills; (3) a secondary gill between the 
"bars"; (4) primary and secondary gills on the pileus margin. On the right lower 
hand portion of this figure is shown a part of the involuted pileus margin. X 20. 
Fig. 62. A tangential section through the involuted margin of the pileus, 
showing the relation of the involuted margin to the gills. X 20. 
Fig. 63. A tangential section through the margin of the pileus just within the 
limit of the involuted margin. It shows very clearly how the marginal hyphae have 
been pushed against the gills. X 20. 
Plate X 
Figs. 64-69. Clitopilus novehoracensis. 
Fig. 64. A higher magnification of the apex of Fig. 48, showing the converg- 
ing of the hyphae. X 200. 
Fig. 65. A higher magnification of a portion of the pileus primordium, show- 
ing the spreading of the hyphae at the apex. X 200. 
Fig. 66. A higher magnification of the palisade layer. Its elements are in- 
creased by intercalary growth. This, together with the increase in size of the 
hyphae, produces the compact palisade. X 300. 
Fig. 67. A cross-section through the stipe, showing the first fold in the palisade 
layer. It is an outward growing salient, the rudiment of a lamella. X 300. 
Figs. 68, 69. Transverse sections through the pileus margin and stipe, showing 
further development of the gill salient. The apical growth of the gill is well shown 
by which it increases in width. The tramal hyphae can be definitely made out. 
X 300. 
Figs. 70-74. Clitocyhe cerussata. 
Fig. 70. A median longitudinal section of a young basidiocarp, showing the 
basidiocarp primordium. It is a homogeneous weft of slender, interlacing hyphae, 
whose general direction is longitudinal and converge at the apex. X 20. 
Fig. 71. A median longitudinal section, showing the diverging hyphae at the 
apex. This serves to separate the pileus and stipe primordia. X 20. 
Figs. 72-74. Median longitudinal sections of older stages, showing the centri- 
fugal development of the pileus. The stipe at the same time increases in thick- 
ness. The hymenophore is differentiated in the surface of the annular groove. 
X 20. 
Figs. 75, 76. Median longitudinal sections, showing further growth of the 
pileus. The margin curves down and toward the stipe. X 20. 
Fig. 76. A median longitudinal section of a more mature plant, showing its 
general habit. The strongly incurved margin is well shown. X 20. 
Plate XI 
Figs. 78-89. Clitocyhe cerussata. 
Fig. 78. A tangential section of the pileus, showing the palisade layer near the 
margin. X 20. 
Fig. 79. A slightly oblique transection through the pileus margin and stipe, 
showing the origin of the lamellae as folds in the palisade layer on the upper por- 
tion of the stipe. _ X 20. 
