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18. The mycelium in the wood-cells about the ducts and the 
medullary ray-cells. Examine the cell-walls. They are thinner than in 
the healthy wood. Note that the spring wood of each annual ring is 
more affected than the autumn wood. 
19. That some of the tissues in the diseased wood take the stains 
differently than they did in healthy wood; which tissues? In the diseased 
wood, the mycelium also is stained red. 
The destruction or removal of the lignin from the cell-walls explains 
the lighter color of the decaying wood; the partial destruction of the 
cellulose walls accounts for its crumbly nature. 
Make an enlarged DRAWING of a cross-section of the affected wood to 
show all changes which have occurred and the location and character of 
the mycelium. 
REPORT 
1. Give the method of treating the fence posts and explain the 
philosophy of the treatment. (See Farmers’ Bul. 387.) 
