DISEASES OF TAXODIUM AND LIBOCEDRUS. 47 
a distinct mycelium is present, and the probabilities are 
strong that it is the one which brings about the decay of 
the wood. The hyphae are brownish when young, but 
soon become colorless. Their chief and striking characteristic 
is the presence of very many clamp connections (PI. 5, fig. 
1). Brefeld,* Hartig,f and others have shown that these 
organs are to be found among the Basidiomycetes, particu- 
larly among the Agaricineae and Polypore?. Brefeld (1. c.) 
describes their formation in Coprinus stercorarius as lateral 
outgrowths of one cell fusing with the cell beneath it, and 
then forming a separating wall. At such points numerous 
branches usually appeared. Hartig (1. ¢.) describes the 
clamp connections of Merulius lachrymans. In this fungus 
they bud out, and form a branch, sometimes before the 
separating wall in the clamp has fused with the next cell. 
This is a unique case among the Hymenomycetes, as the 
clamps are ‘‘ sterile ’’ in all other forms. 
The clamp connections occur on all parts of the mycelium 
found in Taxodium, but in no case did any of them branch 
as they do in Merulius. The mycelium consists of large 
hyphae with distinct thin walls, and hyphae of smaller diame- 
ter. The larger hyphae are constricted at the points where 
two cells join. They branch frequently, giving rise to the 
hyphae of smaller diameter. These in turn branch and 
rebranch. At certain points a short branch is given off 
which divides very rapidly into the finest threads, of hair- 
like dimensions. These smaller hyphae penetrate the cell- 
walls in all directions. Connections between adjacent 
hyphae occur frequently, also complicated masses, where 
large numbers of hyphae have fused more or less. Asa 
rule there is but very little mycelium to be found either 
in the much rotted wood or the intermediate parts. Nu- 
merous holes occur all through the wood, indicating where 
* Brefeld, O. Untersuchungen tiber Schimmelpilze $316. 1877. 
+ Hartig, R. Der aichte Hausschwamm 14. pl. J, fig. 3. 
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