DEVELOPMENT OF EXOGENOUS SPECIES OF AGARICS 53 
Figs. 64 and 65. X 12 diam. Median and tangential sections of a more 
mature fruit body. The plant is becoming umbilicate and the gills triangular in 
shape. 
Fig. 66. X 210 diam. An enlargement of the section from which fig. 61 was 
taken, showing the uneven surface of the gills. 
Plate IV 
Flygrophorus horealis (figs. 67-81) 
Fig. 67. X 28 diam. Upper part of a young, ova), homogeneous fruit body. 
Figs. 68 and 69. X 28 diam. Later stages. The buttons become very 
elongate. 
Figs. 70 and 71. X 28 diam. The primordia of stipe, pileus and hymenophore 
have become differentiated. 
Fig. 72. X 190 diam. An enlarged photograph of the margin of the pileus 
of the section of fig. 70. 
Figs. 73 and 74. X 28 diam. Sections from a fruit body, showing the palisade 
layer. 
Fig. 75. X 190 diam. The palisade layer of fig. 74 enlarged. 
Figs. 76-80. X 28 diam. A fruit body showing well-developed gill salients. 
The light area, which extends into the gills and between them in the pileus region 
subadjacent to the hymenophore, is the region which has given rise by branching to 
the elements of the hymenophore. 
Fig. 81. X 28 diam. A nearly median section, with a portion of the gill 
attached to the stem. 
Plate V. 
Entoloma flavifolium (figs. 82-100) 
Fig. 82. X 35 diam. Young button in which the pileus primordium is be- 
ginning to develop. 
Figs. 83 and 84. X 30 diam. A slightly older fruit body in w^hich pileus, 
stem and hymenophore primordia have developed. 
Figs. 85 and 86. X 28 diam. The palisade layer is distinguishable, although 
it does not take the stain readily. 
Figs. 87-90. X 28 diam. Serial sections from a fruit body in which the 
young gill salients are beginning to form. 
Figs. 91-95. X 28 diam. A series of sections from a more mature fruit body. 
Young basidia over the surface of the gills take the stain very readily. 
Figs. 96 and 97. X 9 diam. Median and tangential sections of a nearly 
n ature fruit body. 
Fig. 98. X 160 diam. An enlargement of a section of a fruit body in about 
the stage of fig. 85, showing the palisade layer. 
Fig. 99. X 191 diam. An enlargement of the section of fig. 89, showing very 
young gill ridges. Certain elements in the palisade layer are beginning to take the 
stain very readily. 
Fig. too. X 191 diam. An enlargement of the section of fig. 94, showing 
young basidia developing over the surface of the gills. 
