50 FOREST TREE DISEASES. 



substance shows distinct annual layers, and the age of 

 ;i fruiting body can with a certain degree of accuracy 

 be determined by cutting it lengthwise and counting 

 these. 



WHITE POUCH FUNGUS. 



The white pouch fungus (Poly poms volvatus], which 

 causes a slow-working, rather superficial gray rot, is not 

 considered parasitic; it does not endanger living trees, 

 but it is very common, and a short description of it will, 

 therefore, be given here. The annual fruiting bodies 

 appear on most conifers, with the exception of juniper, 

 redwood, and bigtree, very soon after the death of the 

 tree, and sometimes on dead parts of a living tree. 

 They are rather small, light yellow-brown when young, 

 white with age, hoof-shaped, and soft corky to hard. 

 The entire surface is very smooth. The underside, 

 with its tiny spores, is hidden by a thick, leathery skin, 

 which forms a pouch. The pink spores escape through 

 a small hole in this skin. 



INDIAN PAINT FUNGUS. 



The stringy brown rot of white fir, common through- 

 out California, is caused by the Indian paint fungus 

 (E chinodontium tinctorum, Pis. XVI, XVII, and 

 XVIII), a very destructive organism, with a large, 

 black, hoof -shaped, perennial fruiting body. The spines 

 or teeth on the underside of the latter are large and 

 hard and point downward. The interior is a vivid rust- 

 red, and was used by Indians for the preparation of war 

 paint. The fruiting bodies grow on the trunk some dis- 



