TIMBER FUNGI. 203 



killing them entirely, though of course decreasing their productive power. 

 In the cortex much more damage is done. The hyphae grow into the 

 cambium and the wood beneath, and even into the medullary rays, where 

 they obtain their food by piercing the cells. Turpentine flows from the 

 wounds, and this eventually results in the drying up and death of the 

 stem. The latter results from the cuting off of the water supply by the 

 resin which permeates the wood. A swelling of the tissues at the point 

 of attack results in a knot on the stem. 



The teleutospore stage of P. pini is found to live on the common 

 groundsel and other species of Senecio native to Britain. 



(3) Hypertrophy of Cones. 



The following by Professor Roth, from Bull. 13, Div. of Forestry: 



"Among the diseases to which this tree is subject (speaking of long- 

 leaf pine), the disease of the cones, recently discovered and studied by 

 Dr. W. T. Swingle, deserves attention. The cones are attacked during 

 the first year of their existence, and instead of attaining only about 1 

 inch in size, they swell up to the size of a second-year cone (3 inches 

 and more), and take on a bright orange color. Only cones of this 

 species and P. heterophylla have so far been found affected." 



We now come to the consideration of a number of fungi of the order 

 Basidiomycetes, commonly known, so far as they are found on timber, 

 as "bracket fungi." Of these, some are strictly parasitic, others are 

 facultative parasites, and some occur only on thoroughly dead wood. 



(4) Ring Scale of Pine. Trametes pini (Brot) Fr. 



The following from Freeman's "Minnesota Plant Diseases": 



"Ring scale is a very common parasite on pines both in Europe and 

 in this country; it is also known on Douglas fir. The fungus gains 

 entrance to the tree usually through wounds or broken limbs, particularly 

 the older branches, in the heartwood of which no protective coat of 

 resin has been formed. After it has gained entrance to the stem, the 

 mycelium grows in longitudinal strips above and below the points of 

 entrance; in the same year's growth it works from the interior to the 

 exterior. In this way zones of the diseased regions are formed exteriorly 

 (ring scale). The wood attacked by the ring scale undergoes a peculiar 

 disintegration. There are formed in the decaying wood numerous small, 

 isolated patches of the white mycelium of the fungus. These differ 

 from the similar patches of the Trametes root-rot in the absence of 

 black centers. The fruiting body is brown and either forms a shelf or 

 is diffused into a coating over the bark. It is woody and perennial, 

 producing new pore areas successively for many years." 



(5) Root-rot: Red-rot. Polyporus annosus Fries: Trametes radiciperda 



Hartig. 



This dangerous parasite is described by both Freeman and Spalding, 

 from whom I draw. In Germany the fungus infests various species of 

 pine, including P. strobus and P. sylvestris, as also Picea excelsa and 

 Juniperus communis. The life history is not essentially different from 

 that of Armillaria and Polyporus, which will be described later. This 



