Shade Tree and Timber Destroying Fungi. 



249 



marginal accretions wliich are very prominent tlie measurements 

 are as follows: First, 4 cm.; second, 6 cm.; third, 3 cm.; fourth, 

 2.5 cm.; fifth, 3.5 cm.; sixth, 4 cm. The usual size of the annual 

 zone is from 2 to 3 cm. Sometimes, however, they are much 

 smaller, from 4 to 8 mm., and then they are not very prominent. 

 In such cases, however, the color character of the diiferent zones 

 and the character of the under surface make it possible to distin- 

 guish the plant from others. 



83. — Fruit bodies of Trametes ahieiis, shelring form. 



In this and some other forms where the zones are not very dis- 

 tinct it is occasionally ditticult to separate the species from forms of 

 Polyporus a])planatiis. In the latter species the tube surface is 

 sometimes yellowish. In the fresh condition, if a bruise or scratch 

 occurs on the tube surface of Polyporus applanatus the exposed 



