48 
GERTRUDE E. DOUGLAS 
Formation of the Gills.- — Very early stages in the formation of the 
gills were not obtained, but the serial section (figs. 111-115) of an older 
fruit body, which is developing gill ridges, shows stages corresponding 
to those passed through in the development of E. flavifolium (figs. 87- 
95). The gills are, however, much more crowded than in that species. 
Certain elements on the surface of the folds in E. grayanum stain very 
deeply and become very conspicuous (figs. 112, 113, 119, 121). These 
are immature basidia, each of which contains at this stage a single 
large nucleus (fig. 121). They are not as numerous as they are in an 
earlier stage in E.flavijoliiini, where they formed a conspicuous stratum 
in the palisade layer (figs. 89, 99). It may be due to differences in 
the staining reactions. Figures 1 16-120 represent a slightly older 
stage of development. The gill salients are so crowded that they are 
developing somewhat irregularly. In figure 116 the decurrent tooth 
on the stem is noticeable. 
EnTOLOMA CUSPiDATUM Pk. 
(Figs. 122-139) 
Early Stages. — Rhizomorphs of parallel hyphae produce the fruit 
bodies which are at first nearly homogeneous in their composition 
(fig. 122). By progressive growth at the apex there is formed a 
button in the stage of figure 123, which is just beginning to show a 
differentiation into pileus and stem primordia by the formation of an 
annular furrow. Later (figs. 124 and 125) the differentiation of these 
two main regions becomes more marked. The tissue in these fruit 
bodies was somewhat shrunken in the preparation processes, so that 
one cannot determine in them with certainty whether the primordium 
of the hymenophore has as yet developed. It can, however, be 
definitely ascertained in figures 126 and 127 and 138, where it consists 
of narrow, crowded, pointed elements, which take the stain readily in 
contrast to the looser subhymenial tissue. This soon gives place to an 
even palisade tissue (figs. 128, 129 and 137). Here the hyphae have 
increased in diameter, are very crowded and, as was noticed in the 
case of Hygrophorus miniatus, are more deeply stained next to the 
subadjacent tissue. 
Further Development of the Fruit Body. — The gills appear as in 
the case of the two previous species as centrifugally growing ridges, 
