11 



the extensive spruce groves of both older and younger trees presented 

 excellent opportunities for a study of the commoner forms. Collec- 

 tions of wood and fungi were made at all points visited. The basis of 

 this report consists of lield notes made in the regions visited, together 

 with brief descriptions of the various forms of diseased wood. When 

 the opportunities permitted, inoculations were made, by means of 

 spores and mycelia, the results of which will not be apparent for many 

 years. 



PREVIOUS WORK ON DISEASES OF TREES. 



Practically no work has so far been done on the diseases which affect 

 the woody parts of the forest trees of the Northeastern States. Many 

 descriptions have been published of the fungi whicU grow on these 

 trees, but these deal mostly with the fruiting portion of these fungi 

 and but rarely with the effects which they l)ring aliout in their sub- 

 stratum. Nearly all of the fungi of this class have been very 

 thoroughly studied by Hartig^ in Germany, and many of the conclu- 

 sions of the present paper correspond with the results which he 

 obtained. His studies, however, were confined to the effects of the 

 fungi on the forest trees of Germany. The only notes on the forest 

 fungi of America which the writer was able to find are those in 

 Sargent's Silva of North America.^ A nimiber of the commoner fungi 

 are there referred to briefly. The majority of these, however, are leaf 

 fungi, viz, Dasyscyj^ha willkommii R. Hartig. ''said to occur in the 

 United States, etc.," the various species of Peridermium, and a few 

 others. 



The catalogues of floras report many of the fungi herein noted, but 

 the mere record of the occurrence of a fungus at one or more locali- 

 ties is of so little value in this connection that it was not considered 

 worth while to present even an enumeration of them here. 



KINDS or FUNGI GROWING ON FOREST TREES AND THEIR 

 RELATION TO FOREST PROBLEMS. 



Of the fungi found growing on the wood of the coniferous trees 

 but a small number bring about changes which completely destroy the 

 wood. Many fungi grow on the bark of a dead tree or their mycelia 

 penetrate into the living bark, where they flourish, but go no deeper. 

 Others, again, grow in the bark and sapwood of trees after the latter 

 have died, and in so doing destroy these parts. A third class grows in 

 the heartwood only, or in heartwood, sapwood, and bark, whether the 

 trees are alive or dead. Several of the last-mentioned class attack 

 living trees and slowly ])ring about changes which ultimately result in 



^Hartij:, R. Zersetzungserscheinungen des Holzes dor Nadelholzbaumo und der 

 Eidie. 1.H78. 

 " Sargeut, C. S. Silva of North Ameriai. 12:5,26. 1898. 



