20 THE POLYPOBACEAE OF WISCONSIN. 



rot in the fir trees produced by F. ungulatus, yet there were few 

 sporophores found on these trees, either living or dead. The most 

 abundant sporophores were found on hemlock, tamarack, and birch; 

 next in order comes white pine and spruce; and lastly red pine. On 

 all of these trees sporophores were found on both living and dead 

 trees. Large pilei were found only on tamarack, birch and hemlock. 

 Those on the other trees were always small. 



The pilei were never found higher than four or five feet from the 

 ground; usually a foot or two above the ground. Frequently there 

 were a half dozen large pilei found at the base of a tamarack or hem- 

 lock. White and red pines are often decayed at the center but do not 

 phow any sporophores or other signs of infection or disease on the out- 

 side. Sometimes the pilei do not form on the trunks until they are 

 prostrate. In that case they osually grow out near the place where 

 the trunk broke. 



The decay produced by F. ungulatus differs from any of the others 

 so far described, in that it is not distinctively either a heart rot or a 

 rot of the sap wood, but may destroy either or both; in fact, it ulti- 

 mately does in most cases destroy both, no matter in which region it 

 starts. This, however, is true in a lesser degree of the firs. There is 

 nearly always a shell of sound sapwood of greater or lesser thickness 

 in them, although the whole interior may be changed to a brittle brown 

 substance. In tamaracks, the fungus apparently spreads with as much 

 ease in the sapwood as in the heartwood. 



"Wood that is destroyed by this fungus turns to a light brown, 

 lighter than that produced by Lenzites sepiaria or Fomes carneus. It 

 is light, dry, and extremely brittle, often collapsing at a touch. It is 

 much cracked in all directions, as if dried suddenly. Sheets of white 

 leathery mycelium spread through the cracks in every direction, es- 

 pecially in the cracks between the rings of growth. 



The brown decayed wood turns red when treated with phloro- 

 glucin in presence of hydrochloric acid, from which it appears that 

 the lignin has not been reduced. In the earlier stages of decay there 

 is some cellulose still present, as can be shown by staining with zinc 

 chloriodide. 



On the road to Razorback Lake, near Star Lake, a tamarack tree 

 fifty-seven years old, and about ten inches in diameter near the ground, 

 was found infected with Fomes ungulatus. On one side was a large 

 wound produced by the falling of a white pine not more than twelve 

 years previously. This wound was nine inches wide at the base and 

 extended upward for about four feet. Out of the wound and out of 

 the bark beside it five small pilei of the fungus were growing. The 



