94 Journal of Agricultural Research VOI.IV.NO. i 



from 2 to 4 feet in diameter and were irregularly circular in shape, as if 

 the causal agent had started from the center. 



Later in the season, near the borders of these areas and at the base of 

 the stems of the dead seedlings, deep-brown, effused, undulating, fruit- 

 ing structures appeared, which were at once recognized as those of Rhizina 

 inflata (PI. VIII, fig. 2). As to the connection of these fruiting struc- 

 tures with the mycelium beneath them in the forest mold and with that of 

 the roots of the diseased seedlings, there seemed little room for doubt. It 

 did not seem probable that the base of the diseased plant would be com- 

 pletely inclosed by the fruiting structure, with its peculiar rootlike fibrils 

 (PI. VIII, fig. 3) mingling with the mass of mycelium about the diseased 

 roots, without having some connection with it. Such a seedling with fruit- 

 ing body attached was carefully removed from the soil and placed in a dish 

 of water, in order to allow the attached earth to fall gradually away. 

 It was found that the numerous rhizoids or strands of mycelium by which 

 the fruiting structures are attached to the substratum were continuous 

 with the mycelium surrounding the diseased roots. These roots were 

 microscopically examined and showed that the internal mycelial system 

 ramifying in the cortical parenchyma and in the sieve tubes of the bast 

 was a continuation of the mycelium which connected up the rhizoid 

 strands of the fruit body. 



By shaking in boiled water a quantity of soil which had been burned 

 over the previous year and which showed no signs of fungous growth, a 

 solution was prepared to which a large quantity of spores of Rhizina 

 inflata was added. This solution was thoroughly sprayed about the base 

 of several healthy 3- to 4- year-old white-pine seedlings (Pinus monticola) 

 growing on burned ground in another part of the forest. The sprayed 

 seedlings appeared slightly reduced in vigor in the fall of 1912 and by 

 July of 1913 they were dead. The roots of each were infected by the 

 same clinging mass of mycelium previously described. The stems and 

 leaves were free from any other diseases. It is believed that this result, 

 although not obtained under control conditions, furnishes some experi- 

 mental proof of the parasitism of Rhizina inflata as it occurs in the 

 Northwest. 



Underwood (1896) reports the distribution of the species as follows: 

 Connecticut (Thaxter), New York (Peck), Rhode Island (Bennett), Penn- 

 sylvania (Schweinitz), Wisconsin (Bundy), North Carolina and South 

 Carolina (Curtis). The range of Rhizina inflata is further extended by 

 the writer, who has collected it at the following stations: Priest River, 

 Idaho, in Kaniksu National Forest on Pinus monticola, Tsuga heterophylla, 

 and l^arix occidcntalis; Coeur d'Alene National Forest, Idaho, on Pinus 

 monticola and Abies grandis; Thompson Falls, Mont., in Cabinet National 

 Forest, on Pinus contorta; Missoula National Forest, Mont., on Pinus 

 ponderosa; Lolo National Forest, Mont., on Pinus monticola; Ely, Minn., 

 in Superior National Forest, on Pinus divaricata; and Salmon Arm, 

 British Columbia, on Pseudotsuga taxijolia. 



