FOREST DISEASE SURVEYS. 



writer has tested and proved this assertion in practice while employed 

 by the Forest Service on the Big Mole timber survey made in 1914 

 in the Deerlodge Na- 

 tional Forest of 

 Montana. From the 

 data thus collected 

 pathological maps 

 were made, giving 

 in colors the areas 

 of the stand in- 

 fected, respectively, 

 with the pine rust 

 ( Cronartium coleo- 

 sporioides (D. and 

 H.) Arthur), both 

 gall and blister 

 forms, mistletoe 

 (Razoumofskya 

 americana ( N u 1 1 . ) 

 Kuntze), heart-rots 



Fig. 7. — Fomes pinicola, 



the red-belt 

 rand fir. 



Fomes growing on 



{Trametes pint (Brot.) Fr. 

 schweinitzii Fr.), and various other diseases (fig. 1 



and Polyporus 

 . Careful notes 



Fig. 8. — Typical rot of the red-belt Fornes in grand fir ; cross and tangential sections. 

 Note the strands of white felty masses (mycelium) throughout the rotted areas. 



were taken as to the percentage of infection in each case, and a closer 

 estimate of the amount of cull was made possible. In one particular 



