36 



a mass of separate fibers, which can be pulled out individualh'. This 

 can be seen at the ends of the piece of wood shown in lig. 2 of PI. 

 VIII. 



FKUITING ORGAN. 



The fruiting^ or^an of this fundus is exceeding-ly common on all the 

 affected trees and has been collected in Maine, New Hampshire, Ver- 

 mont, in the Adirondack forests of New York, and in the forests of 

 Toronto, Quebec, and New Brunswick. It is readily distinguished 

 from allied forms by the light red- brown color of the hy menial sur- 

 face, the regular small round pores, and characters of the hj'menial 

 layer shortly to be described. 



The form of the pileus A'aries exceedingly and is almost a distinct 

 one for every host plant. Hartig, in describing what evidently cor- 

 responds to this fungus, ascribes the difference in form of the pileus 

 and position on the trees to the different amounts of resin or turpen- 

 tine which the wood of the different trees contains. Trametoi ijini^ 

 according to him, forms brackets around the stump of dead branches 

 in the Pine, the Spruce, and the Larch, while on the Fir the sporo- 

 phores may appear at any point on the bark. This is true only to a 

 certain extent for the trees of the Northern woods. Travietes pini is a 

 very common fungus on nearly all the pines so far seen, and on these 

 trees it alwaj's forms very large brackets, which grow, as Hartig says, 

 from old branches. On the Spruce, the Fir, and the Tamarack this does 

 not hold, for on all three of these trees the sporophores form at the 

 ends of old branch stubs and at scattered points on the bark. The 

 resin content of the Spruce is somewhat higher than that of either 

 Tamarack or Fir, and on that account, possibly, the sporophores are 

 more common at the ends of branches. In PI. XII a number of the 

 forms as the}^ are found on the White and Red Spruces are shown. 

 The bark of these trees consists of corky scales which are constantly 

 being peeled off by newer ones developing beneath. The mycelium 

 of the fungus, after having penetrated through the sapwood of an 

 affected tree, grows rapidly into the 3'ounger parts of the bark and 

 ultimately appears as small cushions under several of the bark scales. 

 These cushions arc bright red-brown and have a velvety margin com- 

 posed of thick-walled hyphtv. which rapidly spread out over the adjoin- 

 ing scales, forming a flat sheet (tig. 4). While' the growth in a lateral 

 direction is going on, and when the flat sporophore is scarcely one- 

 sixteenth of an inch (about 1.5™"') in width, some of the central hyphse 

 elongate, leaving small pockets Ijetween them which form the pores 

 of the hymenium. The lateral growth may go on for several years, 

 while at the same time a downward growth of the hyphse which form 

 the walls of the pores brings about an increase in thickness. It ought 

 to be said that this tvpe of spoi'ophore was found only on the under 

 sides of fallen logs or branches. When the sporophores form on a 



