THE -LAMELLAE IN COPRINUS MICACEUS 
353 
In many cases the nuclei in these cells are well differentiated and 
both the nucleoles and chromatin granules are visible. The hyphae 
found in the portion of the pileus over the lamellae are oriented and 
appear to be growing downward; still in many well stained sections 
hyphae are also found growing downward as indicated by the direction 
of the branching. In somewhat later stages the flesh of the pileus 
is made up of broad septate hyphae having a sparse granular cytoplasm 
in which two nuclei are regularly present. The lamellae are still 
continuous with the tissue of the stipe below just as they are with the 
pileus above. The hymenial surface is sharply differentiated and 
distinct basidia and cystidia are recognizable. There are no basidia 
formed on the edges of the gills, as shown by Brefeld for other species 
of Coprini. 
Figure 8, a longitudinal tangential section very close to the median, 
represents best the structure of the stipe at this stage. The basal 
portion consists of a compact intertwining mass of hyphae (Jig. 5) 
from which the hyphae of the center of the young stipe arise. The 
hyphae in the stipe which lie exterior to the central region are still 
continuous with the hyphae in the young gills. As we approach the 
outer layer of the stipe, that is, the layer just below the peripheral 
layer of globular cells we find the hyphae become narrow. The density 
of the cytoplasm and the tjiickness of the cell walls make this a well 
differentiated layer. These hyphae can be traced into the pileus 
where they are continuous with the cells of the surface there. The 
growth direction is upward as shown by the character of the branching. 
The further development of the stipe consists primarily in the vertical 
elongation and swelling of the hyphae in the outer and middle layer 
of the stipe. A cross section of the young stipe shows that there are 
two types of hyphae, the wide and the narrow, similar to those which 
have been described by Harper (1902) for Coprinus ephemerus, although 
at this stage the broad type predominates. The cells in these hyphae 
are long as compared to their width and have a homogeneous cytoplasm 
in which a large number of nuclei are found (fig. 16). The nuclei are 
clustered and lie in the center of the cell. 
The increase in size of the stipe is accompanied by the increase in 
size of the primordia of the lamellae and an outward and downward 
growth and expansion of the pileus. The hyphae in the upper portion 
of the stipe near the pileus are intertwining and septate and two or 
three nuclei are invariably found in each cell as shown in figure 18. 
