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THE POPULAR SCIENCE MONTHLY. 



Fig. S.Polyporovs versicolor (Ft.). 



February, 1886, for the use of New York roads, the sap-wood was 

 already discolored, and some new growths of SpJupria took place here 

 in March. Initial decay has already commenced in those ties, which 

 will be facilitated by the conditions occurring when they are placed 

 in the road-bed. 



Fig. 8 is that of Polyporous versicolor (Fr.), which is very common 

 and abundant, and is attached by its margin to the wood so that its 

 form is called dimidiate. Several caps usually project one over the 



other, the lowest being the longest, 

 each succeeding one above being 

 shorter. On the under surface of 

 each cap are the pores just visible 

 to the eye, which bear the spores. 

 The distinct colored bands or zones 

 upon the upper surface give it a 

 beautiful effect, as seen upon the 

 wood it is destroying. It is easily 

 found, as its substance is quite 

 tough and dries before the insects 

 and molds destroy it. It is gen- 

 erally abundant upon the sap-wood 

 of white - oak piles, especially if 

 the bark is left on after felling. It grows on the sap-wood of the 

 white and red oak and chestnut ties ; also upon the sap-wood of 

 chestnut posts, and on the sap-wood and heart -wood of wild-cherry. 

 As a rule, I found it more abundant on sap-wood of the oak than on 

 chestnut ties. My observations refer to the entire length of the Bos- 

 ton and Albany Railroad, and many other roads in New England. 

 The bark should be removed from piles and ties of the woods just men- 

 tioned, as it allows them to season and dry, checking the growth of 

 this fungus ; whether it is alone capable of destroying the heart- 

 wood of chestnut ties has not been ascertained. I never found it 

 growing there, but, instead, Fistulina hepatiea Agarieus Ameri- 

 eanus (Pk.), Polyporus pergamemis (Fr.), Dcedalea quereina (P.), 

 and Polyporus hirsutus (Fr.), the latter being very abundant in old 

 chestnut ties put in a temporary embankment at Worcester, Massachu- 

 setts. It was also abundant in the chestnut curbing of some of the 

 unused hydrants. 



The heart-wood of chestnut ties is not so quickly attacked by 

 fungi as some other woods, most of them being removed on account 

 of the mechanical destruction of the fibers under the rails before de- 

 cay takes place. I have several specimens of mycelia in the heart- 

 wood of chestnut ties, but have only found a few developed efforts of 

 fructification. 



Polyporous applanatus (Fr.) is frequently found upon the sap-wood 

 of many oaks, and is the one I generally find upon the heart-wood of 



