herp ais 
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State Museum or NATURAL HISTORY. 89 
applanatus, Fr.; P. versicolor, Fr.; P. pergamenus, Fr.; Daedalea wnicolor, 
Fr.; D. quercina, Pers., and Lenzites vialis, Pk. 
Polyporus applanatus attacks the heart wood of the white oak tie 
’ and is very destructive, and requires a moderate amount of air and 
moisture for its growth. The characteristic decay of these ties is 
from the under to the upper side, and is most rapid in stone ballast, 
or a coarse ballast which retains a little moisture and permits access 
of air. In a ballast containing considerable loam, which checks the 
circulation of air, and in wet cuts, the growth of the mycelium is 
retarded and the durability of the ties increased. In porous ballast, 
-unless wet, the deeper the white oak ties are imbedded the better are 
the conditions of the growth of the fungi and the more rapid the 
decay of the ties. On the contrary, only imbedding the ties sufficient 
for the stability of the track increases the service of the ties by 
retarding the rapidity of the upward growth of the mycelium. 
Polyporus versicolor attacks the sap wood of white oak ties and 
posts, and to a limited extent the heart wood. 
Polyporus pergamenus attacks those ties from which the bark has not 
been removed. 
Deedalea unicolor, D. quercina and Lenzites vialis have been found on 
ties laid on railroad bridges. 
The structure of the white oak is so firm and dense that it readily 
sustains the heaviest traffic and it is quite difficult to impregnate the 
- internal cells of the ties. Unless a process has been used which would 
sterilize the spores lodged in the wood or possible traces of mycelium, 
the exterior treatment on the unseasoned wood prevents the escape 
of the internal moisture, the sameas a coat of paint. This will hasten 
decay, for it furnishes the requisite conditions for fermentations and 
internal growth of mycelium. 
The fungi attacking ties of the chestnut, Castanea vulgaris, variety 
Americana,-A. D. C. (Castanea vesca, L., variety Americana, Mx.), are 
Polyporus sulphureus, Fr.; P. spumeus, Fr.? ; P. hirsutus, Fr.; P. versi- 
color, Fr.; P. pergamenus, Vr.; Agaricus Americanus, Pk. and A. sub- 
lateritius, Scheeff. 
Polyporus sulphureus is also very destructive to telegraph poles and 
large posts, attacking them near the ground line. 
- The chestnut contains naturally a stronger antiseptic than the 
white oak and resists, in contact with the soil, the growth of the 
fungi until the antiseptic is destroyed by the air, or contact with 
the rails and spikes. The decay of the chestnut tie is from the 
top downwards; therefore the deeper the tie is imbedded 
the longer the body lasts. The full advantage of this is lost in 
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