Nichols- —Binuclcaled Cells in Home Basidiomy cedes. 47 
the main hypha and their base is enlarged in the same fashion as 
is the base of the germ tube. The young branch receives a single 
nucleus from the parent cell. A cross wall is then formed sepa¬ 
rating the branch from the main hypha while it is still very 
small. The nucleus divides very rapidly so that the young 
branch soon contains two or three nuclei. These continue to 
multiply until the mature cells contain as many or nearly as 
many nuclei as the cells of the main hyphae. The clamp con¬ 
nections between adjacent cells are quite abundant although they 
are not formed at every cross wall. They are cut off from one 
of the cells by a cross wall which always shows the deeply stain¬ 
ing convex plates originally described by Hoffman (13) and 
since by Strasburger (24) and other authors. In every instance 
they show the same cytoplasmic structure as the cells which they 
connect. I have found one or two cases in Coprinus in which a 
branch has arisen from one of these clamp connections. 
The secondary branches which arise from the primary hyphae 
do not show the same regularity m their formation. Only one 
is formed from a cell. They are very long and slender and run 
in every direction through the substratum. They anastomose 
with other branches frequently thus increasing the complexity of 
the hyphal system. The nuclei are separated by long distances, 
they are elliptical with a slightly larger nucleole than is found in 
the nuclei of the main hyphae. The cross Avails are difficult to 
locate AAdien, as frequently happens, the convex plates at the 
cross walls are absent. 
The mycelium does not appear at the surface of the culture 
until a fruit body is to be formed. At this stage the character 
of the branching of the mycelium changes. The cells are shorter 
and branch three or four times, each successive cell branching in 
the same way. The cells are also curved backward towards the 
main hypha, thus a tangled mass is formed (Fig. 17). Other 
hyphae from various directions pass into this snarl and branch 
in the same way increasing its size and complexity. Fig. 17a is 
from one of these tangled masses and shows the Y shaped cells 
Avhich are frequently found near the center. The cell walls are 
thick and tinged with yellow. The clamp cells are found at 
every cross wall connecting the adjacent cells. 
