31 



The remaining- portions then form separate centers of growth, which 

 gradual!}' spread over the dead portion and unite, after several years 

 perhaps, completely covering the dead part. A view of such a pileus 

 is shown on PI. IX, fig. 4; several areas have already joined, forming 

 a larger one, and a number of small centers are evident. 



The spores begin to be discharged in July. Growth of the lower 

 side of the pileus takes place at the same time. Black cloths were 

 pinned to the under side in June and by the end of August large por- 

 tions of them were found completely overgrown with hypha?, and 

 pores were beginning to form on the under side of the cloth. While 

 the growing season lasts drops of a glistening yellow liquid are con- 

 stantly being discharged from the hymenium. It is of interest to note 

 here that the secretion of these drops was noticed b}^ Fries in a 

 description of this fungus.^ Several cubic centimeters of these were 

 collected and were found to hold in solution melezitose, the same 

 sugar discharged from the sporophores of Polyporus schweinitzii. As 

 insects, particularly small boring beetles, eat the hymenium with 

 great avidit}^, it is possible that the sugar ma}^ serve to attract these 

 insects to the sporophores, causing them to carry the spores to unin- 

 fected trees. 



TRAMETES PINI (Brot.) Fr. forma ABIETIS Karst. 



Pobjporus jjiceinus Peck. 

 Pohjpoi'us abielis Karsten. 



OCCURBENCE. 



This fungus is very common in the forests of the New England 

 States, and occurs northward into Canada and Newfoundland. The 

 writer found it conmion oh the Spruces and Firs in the Adirondack 

 forests. It grows on nearly all the conifers and has been found by the 

 Writer on the White Pine {Pimis strohus), the Red Spruce {Plcea 

 ruhens), the White Spruce {Plcea ccmadensls)^ the Hemlock {Tsuga 

 canadensis)^ the Larch, or Tamarack {Larix larichia), and the Fir 

 {Abies halsamea). It attacks living trees after they have reached such 

 a size that they form heartwood, and honeycombs the wood in such a 

 way that it appears filled with small holes, many of which are coated 

 with a shining white lining. The changes which are brought about in 

 the wood are difi'erent somewhat for the ditt'erent kinds of trees and will 

 be described separatelv. Of the six trees the Tamarack seems to be 

 the most readih' attacked. A greater per cent of the older trees of 

 this species were fecund affected than of the other five. The Spruces 

 came next, and the Balsam Fir last. 



The fungus enters the trees through the stubs of broken branches 



> Friea, Eliaa. Epicrisis Syst. Myc. 468. 1836-1838. 



