47 
raster than in an opposite direction through the medullar} rays. As 
before stated, t he cells of ( lie medullary rays are iiol si roug ; in all cases 
spiking the ties separates each layer longitudinally from three fourths 
to one inch on each side of the spike, and in many tics the checks ex- 
tend much farther. 
DURABILITY AND FUNGI. 
Ordinary specimens el' Yellow Pine contain from eighteen to twenty 
per cent, of resinous matter, which is supposed to add much tothedur 
ability of the wood. But this does not seem to be the case when the 
wood is put in the ground, or in the road-bed as ties. In such situa 
ttons it is rapidly destroyed by the fungus Lentinus lepideus, Fr., an 
Agaric. 1 have found this so general over a groat extent of territory 
that I am inclined to think if is a fungus peculiar to the heart-wood of 
this timber, especially when the latter is in exposed situations. I have 
found Trameles pini, Fr., on dock-timbers a few times, but more often on 
tics. The mycelium of the latter is yellowish, a color that distinguishes 
it from the clear white mycelium of the former fungus. Long-continued 
warmth and moisture facilitates the growth of the mycelium ofLentinu.s 
lepideus ) and, consequently, rapid destruction of the wood. I have 
samples of Yellow Fine ties from the Panama Railway which were rot- 
ted in two years, while in the Southern States they last from four to six 
years; in the Middle States, from five to eight years. Formerly the 
first Yellow Fine ties used on the New York railways lasted from ten to 
fourteen years. The reason given why the present ties do not last 
longer is that they are now made from timber of " tapped" trees. This, 
nowevcr, is not the sole reason, especially in road-beds where Y^ellow 
Fine ties were formerly used, and where the mycelium of its injurious 
fungus remains from former decayed ties in the road-bed and is ready 
to attack the new summer-laid ties. The rational procedure from these 
observations would be, to replace the unsound ties by such of another 
wood as are not affected by the same fungus. 
When the Yellow Fine wood can be kept comparatively dry, it is very 
durable j this is shown by the ties not decaying quickly where the upper 
surface remains dry, but still does not always indicate what has taken 
place on the inside or underneath. Upon raising the track, many un- 
sound ties are found, which on the surface did not indicate the presence 
of decay. In the vicinity of Albany, N. Y., Y r ellow Fine ties in cin- 
der ballast (from locomotives) are rotted by their specific fungus much 
faster than they arc in gravel ballast. As before stated, the layers of 
wood are checked in driving the spikes, and, moisture thus being ad 
mitted, fermentation takes place and the layers separate under the 
rails, frequently throughout the entire length of the tie. The mycelium 
of LcnthuiH Jepidem ofteK follows the checks, and the decay is thus 
hastened. 
Under severe service it is not uncommon to see the ends of many ties 
of this wood split and crushed, offering "but little support to the rails, 
with the spikes loose. The fermentation, which precedes the growth of 
