Page:Popular Science Monthly Volume 29.djvu/458

442 February, 1886, for the use of New York roads, the sap-wood was already discolored, and some new growths of Sphœria 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 generally 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 Boston and Albany Railroad, and many other roads in New England. The bark should be removed from piles and ties of the woods just mentioned, 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 hepatica—Agaricus Americanus (Pk.), Polyporus pergamemus (Fr.), Dædalea quercina (P.), and Polyporus hirsutus (Fr.), the latter being very abundant in old chestnut ties put in a temporary embankment at Worcester, Massachusetts. 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 decay 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