State Museum of Natural IIistohy 



91 



heavy traffic. It is a wood which cau be easily treated so as to resist 

 the attacks of fungi, and such ties have lasted over thirty (30) years 

 in actual service. 



The fungi attacking the hemlock, T^uga Canadensis, Carr., are 

 numerous. The following is a list so far as observed: 



Agaricus melleus, Tahl. 

 A. campanella, Batsch. 

 A. pomgens, Pers. 

 A. succosus, Pk. 

 A. rugosodiscus, Pk. 

 A. epipterygius. Scop. 

 Paxillus atrotomentosus, Fr. 

 Lenzites sepiaria, Fr. 

 Stereum radiatum, Pk. 



PolyporuH lucidus, Fi-. 

 P. benzoinuH, Fr. 

 P. ejnleucus, Fr. 

 P. Vaillanlii, Fr. 

 P. subacidiis, Pk. 

 P. medulla-panis, Fr. 

 P. pinicola, Fr. 

 P. abietinus, Fr. 

 P. boi'ealia, Fr. 



This wood does not contain any natural antiseptic or preservative, 

 and is readily attacked by a host of fungi, and decays very quickly. 

 It is heavier than white cedar, but lighter than the tamarack, and, 

 when well preserved by metallic antiseptics, makes a valuable tie. 



The fungi destroying the wood of yellow pine, Pinus pahistris, Mill., 

 are Lentinus lepideiis, Fr. See Fig. I. 

 SiDlueria pilifera, Fr. See Fig. HI. 

 Trametes Pini, Fr., and Merulius lacrymans, Fr. 

 The tirst is the most destructive to ties in this vicinity, the decay 



being most rapid on 

 the bottom and 

 extending ui)wards. 

 In porous ballast the 

 deeper the ties are 

 iml)edded the shorter 

 the duration of ser- 

 vice, so far as dcray 

 is concerned. The 

 mycelium requires 

 considerable moist- 

 ure for its growth^ 

 and some air. A bal- 

 last which pnvents a 

 free circulation of the 

 Ixitter checks its growth. The sun and wind (theck its gn)\vth and 

 oftentimes a tie wjiich looks sound upon the surfat-o wilJ be so batUy 

 decaved underneath that its lemovalfrom the track will be necessary. 



Fig. I. Lentinus lepideus, Fr. uu Yellow I'iiu'. 



Showiutr the fruit of the fuuuus on, aud the myeelium iu. 

 the wooii. The size of the fruit varies from an im-h to 

 eight inelies iu difiiuoter. 



