9 



wood, the onh' one found in the investigations here described being a 

 hirge carpenter bee, which made long tunnels through the entire length 

 of the trunk. Here and there a few borers 



get in after 

 V and VI. 



the tree dies, as shown in Pis 



WHITE ROT OF THE RED CEDAR (POLYPORUS 

 JUNIPERINUS N. SP.). 



..--4 



n 



tf 



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I 



Of the two forms of fungi attacking the 

 red cedar the most striking is the one which 

 ultimately causes long holes in the heartwood. 

 These holes often unite and thus make a 

 tube through the entire trunk. The trees 

 attacked In- this disease are seldom less than 

 25 years old and generally are much older. 

 When a diseased tree is cut down several 

 holes are found in the heartwood, the size 

 of these varying according to the stage of 

 decay. (Fig. 1 and PI. HI.) At first the 

 holes are separated by long stretches of wood, 

 which is apparently unchanged. A close 

 examination, however, shows that this wood 

 is not as deep a red as is the sound wood, 

 but has become somewhat of a red brown. 

 The holes themselves are coated with a bril- 

 liant white lining (PI. II), which presents 

 a striking contrast to the deep red of the 

 heartwood. The layer of sound wood imme- 

 diately outside the white lining has the same 

 red brown color as the wood between the 

 holes, and the successive rings outward from 

 the hole show all shades of color from the 

 red brown to the pure red of the sound 

 wood. The holes are from 3 to 6 inches 

 long and of variable width. They are par- 

 tially filled with a velvety mass of reddish 

 yellow mycelium, which glistens with many 

 drops of a colorless liquid, apparenth' exuded 

 by the hj'phfe, and with masses of wood 

 fibers of a reddish brown color in the last 

 stages of disintegration. From the ends of 

 the holes long, glistening white fibers project into the cavity, and on 

 the longitudinal walls these fibers extend from end to end. (PI. II.) 

 The fibers consist of almost pure cellulose of the original wood ele- 

 ments, the encrusting lignin substances having been removed. In 



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INCHES 



Fig. 1.— Longitudinal section of a 

 • cedar log showing position of 

 holes caused by Polyporus juni- 

 per inus. 



