DISTRIBUTION AND HOST WOODS. 



13 



mentioned as occurrino; ])arasitically. llcdgcock (H Xo. 1032), 

 however, found an instance where a tree of Picea engelmanni about 

 4 inclies in diameter was sharply l)ent by snow and was unable to 

 straighten uj) when (lie weight was removed. The bark became 

 loosened on the top of the bend, and this gave an entrance for tlie 

 fungus, which worked downward in the injured wood tissues until 

 only a small ]X)rtion of the lower side of the trunk was alive (fig. 1). 

 There seems to be no doubt in this case that the fungus was a wound 

 ])arasite. Six inoculations into living trees of Pinus palustris made 

 1)V the writer were 

 wholly without re- 

 sult. For all prac- 

 tical purposes Leii- 

 zites sepiaria is a 

 saprophyte, attack- 

 ing timber wliicli is 

 piled for seasoning, 

 or which is m use 

 but exposed to the 

 elements. 



Lenzites sepiaria, 

 has been found by 

 the writer upon tlie 

 heartwood of Tsuga 

 canadensis (|| No. 

 2085) and Larix lari- 

 cina, and it often 

 attacks the outer 

 layers of the heart- 

 wood in many other 

 species. Whether 

 it is able to rot the 

 resmous heartwood 

 of the southern pines seems questionable. The writer has seen no 

 instance where this had taken place, except in the outer layers of 

 heartwood which were not so completely fdled with resin as the inner 

 ones. 



Fig. 1.— Cross section of living tree of Picea engelmanni, showing para- 

 sitic action of Lenzites sepiaria. The five annual rings on lower side 

 are alive, but tlie inner one shows the encroachment of the fungus. 



METHOD OF ENTRANCE AND RATE OF GROWTH OF LENZITES SEPIARIA. 



Lenzites sepiaria is undoubtedly able to penetrate wood where it 

 is cut across the grain, and under most conditions can probably enter 

 radiall}^ if there is some snuill break in the fd)ers so that it can get 

 between them. The evidence seems to show that when it enters 

 upon the side of a timber it docs so by means of season cracks. 



214 



