45 



ground 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 hyphte, 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 overturned 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 under the bark scales of the roots of many healthy spruces in a 

 way which seemed to indicate that they were ])egiiming to enter the 

 root itself. Hypha3 from these masses extend into the soil, V)inding 

 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 hyphie 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 were buried in soil in a greenhouse in September, 

 and in four months the hyphffi 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 probably one of the ways 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 Polyporus sclviDeinitzii does. The fruiting 

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

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

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

 the trunk had broken some 6 feet (2 meters) from the ground. The 

 wood was very soft and showed numerous black spots surrounded l)y 

 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 mycelium of this fungus induces is. not to be 

 confused with that caused by any other fungus. Spruce wood when 

 very much decayed is moist, almost wet at times, and can be comi)ressed 

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

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

 felt of hypha^ 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 scatt«M-ed throughout the wood in most triMvs and are 

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



