37 



living standing tr^e they take the form of extended sheets on the 

 lower side of the uppermost l^ranches or form as sessile l^raekets of 

 varied shape around old stul)s of branches or again as sessile 

 brackets at scattered points on the side of the main trunk. Fig. 3 

 shows a sporophore growing on the under side of a branch. In such 

 a case the mycelium grows out through the bark, forming a long vel- 

 vety cushion oftentimes several feet in length. This cushion rapidly 

 grows laterally, and on its lower surface the pores arise. The growth 

 of such a sporophore may go on for many years. The under side of the 

 branch shown on PI. Xll, hg. 3 was covered for a distance of 10 feet 

 with the brown sporophore. As the latter increases in width it sooner 

 or later develops a free upper surface where the body of the sporo- 

 phore projects beyond the curved surface of the branch. The cracks 

 appearing in the wood are due to drying. Fig. 6 shows the sporo- 

 phore as it occurs on the vertical trunk of a living tree. Here a form 

 results which approaches most closely to Trametes pini (Brot.) Fr. 

 The mycelium grows out from between the bark scales, forming a 

 small knob or sometimes several beside or above one another. On the 

 lower side the pores soon appear as shallow pits, which are increased 

 in depth by downward growth of the hyphse forming their walls. The 

 upper surface of the cushions becomes brown and, because of alter- 

 nate periods of growth and rest, concentric lines arise which are more 

 or less obscured by the hairiness of the surface. In forms of this 

 kind the directive influence of geotropic forces on the position of the 

 pores is very marked. The pores always extend verticall}", and on 

 that account when found on a perfectly horizontal surface their open- 

 ings are almost round. As one passes on into the oblique portion of 

 the lower surface the openings become more irregular and the lower end 

 portions of the tubes are exposed until they appear as hollow grooves. 

 Where for any reason the position of the trunk or branch upon which 

 a sporophore grows is changed, the direction of the pores changes like- 

 wise, and instances of this kind are very common. 



On old Spruces ends of broken branches are points where the brown 

 sporophores of this fungus may be found almost without exception. 

 Two cases of this kind are shown on PI. XII, tigs. 5 and 7. The Spruce 

 loses man}^ of its branches during windstorms, far more so than the 

 Fir or Tamarack. The butt end of a broken branch keeps on growing 

 after the death of the outer portion, and in that way large knobs are 

 formed which may in time cover the wound entirely. It is an exceed- 

 ingly slow process, however, and where, as is frequently the case, the 

 branch breaks ofl' at a distance of a foot or more, as shown on PI. XII, 

 fig. 5, it rarely if ever heals over.^ Such branches form the places 



^ There is apparently in the Spruces little of that most efficient natural i)runing 

 which takes place in the Pines, where a dead branch breaks off very close to the 

 trunk. 



