THE POLYPORACEAE OF WISCONSIN. 15 



ones in the fall wood, as though the thick-walled cells were more re- 

 sistant. 



The wood during this stage is comparatively brittle and can be 

 broken into small pieces with the fingers, but cannot be pulverized as 

 in the later stages. Later, all the wood affected turns to a pale brown 

 and is very brittle. The effect on the wood cells is well marked, and 

 similar to the effect produced by Fomes pinicola, Trametes odorata and 

 Fames carneus. 



The hyphae appear strong and vigorous, light colored and much 

 tangled. They develop chiefly lengthwise through the cells, not pene- 

 trating through many layers of cells. This perhaps is why the decay 

 and the development of mycelium follows the cracks and chinks in the 

 wood, the lines of least resistance. Strong and vigorously growing 

 hyphae usually contain large bluish-green granules, as shown in Fig. 

 9, which are soluble in alcohol, but are made clearer and somewhat 

 darker with ammonia. 



Trametes pini (TJiore) Fries. Ring Rot. Dry Kot. 



Looked at from above, the pileus appears hoof-shaped or ungulate, 

 but the lower surface is concave and usually uneven. The base is 

 usually decurrent, and out of it very often several small pilei spring, 

 so that the sporophores thus become imbricated and confluent. The 

 young actively growing portion is of a rich golden brown color, soft 

 and velvety, but soon changes to dull ferruginous and becomes rough, 

 almost strigose. The surface finally becomes black and covered with 

 moss and lichens. The concentric furrows or sulcations are narrow 

 and numerous. The margin is thin and acute; the substance of the 

 pileus hard, of a rich yellowish brown. The pores are small and regu- 

 lar in the younger parts but become larger and more irregular, al- 

 most sinuous, in the older portions. The tubes usually become more 

 or less white-stuffed. From the walls of the tubes project numerous 

 large awl-shaped cystidia, which are sometimes one-fifth of the di- 

 ameter of the tube in length and of a deep red-brown color. 



T. pini was found on tamarack, white pine and hemlock. In 

 Oneida and Vilas counties it was found most abundant on tamarack 

 and white pine, and in Ashland County on hemlock and tamarack. 

 The fruiting bodies were rather rare on white pine but abundant on 

 tamarack. They were found on both living and dead trees. In the 

 case of hemlock only, were they found on fallen trunks. 



Although the sporophores were rare on white pine, yet I believe 

 that white pine was abundantly infected more than any of the others. 



