45 



groiiiicl and left standing, while in still others wounds were made with 

 an axe to permit the entrance of air, as it was thought that fructifica- 

 tion might thus be induced. After two weeks the ends of the pieces 

 buried in sphagnum were covered with a white film of hypha^, which 

 gradually turned yellow, and after two months began to form shallow 

 pores. The same took place in practically every one of the trees which 

 were o\'erturned or wounded. In all the localities visited where trees, 

 both older and younger, had been overturned, this fungus was found 

 again and again, and associated with it the form of wood decay 

 described below. (Pis. XIV and XV.) 



Masses of yellowish mycelium were sometimes found growing out 

 from luider the l^ark scales of the roots of many health}^ spruces in a 

 way Avhich seemed to indicate that they were beginning to enter the 

 root itself. Hyplue from these masses extend into the soil, binding 

 together the particles so that dense clumps are formed, varying from 

 the size of a pea to as large as two fists put together. The growth of 

 the hvphie in the soil is a very rapid one; they can be grown with 

 ease in moist soil and form the peculiar lumps in a few weeks. Pieces 

 of diseased trunks Avere buried in soil in a greenhouse in September, 

 and in four months the hypha? had grown through the soil of the bench 

 in all directions. It is thus very evident that this fungus grows in the 

 ground rapidly and that this is probabh^ one of the wa3^s in which it 

 enters standing trees. This is made more probable by the fact that 

 one finds all of the trees in a certain area affected with this fungus, 

 both younger and older ones. Each probably infected its neighbor 

 much in the way in which Pohjporu8 schiceinitzii does. The fruiting 

 portion of the fungus has been found on living White Pine, Ked and 

 White Spruce, Fir, and Hemlock. A large Hemlock, almost 2 feet 

 (O.T) meter) in diameter (near Houlton, Me.), had been blown over and 

 the trunk had l^roken some 6 feet (2 meters) from the ground. The 

 wood was very soft and showed numerous black spots surroimdcd by 

 white areas. The fruiting organs were forming in the chinks and 

 crevices of the trunk, and on the stump. The tree was alive at the 

 time it was seen. 



STRUCTURE OF DISEASED WOOD. 



The decay which the nn^celium of this fungus induces is not to be 

 confused with that caused b}' any other fungus. Spruce wood when 

 very nuich decayed is uioist, almost wet at times, and can be compressed 

 nuich like a sponge, when quantities of water will drip from the mass. 

 Larger and smaller cavities of very irregular shapes, lined with a tough 

 felt of hyphte, yellow on the inner side, are found throughout the 

 wood. Such a cavity is shown in part at the bottom of PI. XIV, fig. 2. 

 The cavities are scattered throughout the wood in most trees and are 

 generally partially filled with a pale straw-colored licjuid. The wood 



