16 BULLETIN 191 



is indicated by the constant reference made to their occurrence by 

 German writers. Von Schrenk (2) speaks of them as being "extreme- 

 ly common on all (New England) affected trees." Specimens have 

 been collected from forests in Maine, New Hampshire, Vermont, New 

 York, Ontario, Quebec and New Brunswick. However, the writer did 

 not find these fruiting bodies as common, at least in Vermont, as they 

 have been represented to be. No trace could be found on a large 

 proportion of the infected trees, the only external sign of the dis- 

 ease being an abnormal exudation of pitch from knot-holes and a gen- 

 eral pale and unhealthy condition of the foliage. However, the sporo- 

 phores were found occasionally on every diseased tract. 



The sporophore of Trametes Pini is easily distinguished from al- 

 lied forms by the light red-brown color of the hymenial or fruit-bear- 

 ing surface and by the regular small round pores. The pores on the 

 specimens obtained in Vermont seem smaller than those occurring 

 on specimens from other sections. The form of the pileus or cap varies 

 with the species of the host plant. Hartig (1) ascribes this difference 

 to the various amounts of resin contained in the trees of the several 

 species. The sporophore on the pine appears characteristically in the 

 form of a large bracket, situated on the surface of the tree where an 

 old branch stub has broken off. Plate III shows this characteristic ap- 

 pearance. An exudation of pitch almost always accompanies the pres- 

 ence of the fruiting body. Plate III shows two specimens of fruiting 

 bodies or sporophores collected, respectively, at Bradford and Bur- 

 lington. In the case of the spruce, tamarack and fir, these characters 

 do not hold. The form of the sporophore varies from that of an in- 

 crustation to that of a bracket, and it does not confine its location to the 

 nodes but may develop at any point. 



These sporophores give rise to the spores which are carried about 

 by the wind until they find a suitable place for germination. Where old 

 branches have been broken off, exposing the heart-wood before com- 

 plete protection to the wound has been effected "by the resinous deposit 

 in the branch stub, the spore finds the most favorable conditions for 

 entrance and germination. Its progress in the heart-wood is rapid, but 

 when it reaches the resinous sap-wood its advance is slower. About this 

 time the sporophores begin to form. Where the dead branches have 

 been broken off close to the trunk, the hyphae grow out from the stub 

 and form a cushion. Von Schrenk (2) has explained carefully in de- 

 tail the progress of the growth of the sporophore on pine, spruce and 

 tamarack. The cushion formed on the branch stub is very small at 



