42 Disease and Death of Trees — Generalities 
the wood body. While the tree can go on rotting for years, 
to all appearances without detriment, its stability is under- 
mined, and finally a windstorm may lay it low in full leaf 
and otherwise in full health. 
These fungi gain entrance to the wood through wounds 
made by broken or badly pruned branches, by broken bark 
or through injured, exposed roots. 
On the ragged surface of a broken branch stump, and 
even on a well-pruned but unprotected wound, dust and 
water collect and form a seed bed 
on which the fungus spores — cor- 
responding to the seeds of other 
plants, minute or microscopic, 
easily scattered by the winds — 
can locate and sprout. These grow 
into the wood by rooilike hy- 
phe, which bore through and 
between cell-walls, branching mul- 
tifariously and forming a mass of 
white meshes penetrating the wood 
ree otem ofa pine Es ct in all directions —the so-called 
wood, 5, resinous ‘‘light” q2ycelzum. ‘This draws its suste- 
wood, c, partly decayed . 
wood or punk, d, layer of nance from the tree, destroying 
hving Spore bre 2 “ cell-walls and absorbing cell con- 
fluted upper surface of the tents. As a consequence the wood 
fruiting body of the fungus, dries, shrinks, cracks, turns reddish 
which gets its food through 
a great number of fine brown, or else becomes spongy and 
threads (the mycelium), its . . . 
vegetative tissue penetratmg Yellowish white. The mechanical 
the wood and causing its : - 
decay (Department of destruction proceeds as the my 
Agriculture, Division of For- celium pr oceeds. 
estry Bulletin, No 10) . . 
Finally, sometimes after years, 
the mycelium forms a fruit-body on the outside of the 
tree, the readily recognized toadstool making its presence 
