572 Forestry Quarterly 



done for certain other classes of defect. Since detailed estimates 

 by types and stands at all elevations are made, it will be possible 

 to indicate very definitely on the field map in colors, shadings, or 

 lines the most severely infected areas. These pathological maps,* 

 as they may be termed, would be immediately available when the 

 infected areas came under sale. Of coiirse, this part of the work 

 would have to be done by men who have had instruction and 

 experience in recognizing mistletoe and judging injury. This 

 information is being rapidly gained by the men* on the forest. 

 Some mapping of this kind has already been done under the 

 writer's direction by E. E. Hubert of this Laboratory, enough, 

 in fact, to show the value of it. It is planned to carry on the work 

 from year to year until all the great areas of mistletoe infection in 

 District 1 have been mapped. 



After the zones of greatest mistletoe infection have been deter- 

 mined, the next step is to devise some means by which a begin- 

 ning may be made to eradicate them. Unfortunately at the pres- 

 ent time conditions are such that no more extensive meastires can 

 be adopted than those afforded by free use permits, activities of 

 rangers, and timber sales. It seems that it is entirely possible on 

 some National Forests where mistletoe is abundant to desig- 

 nate only mistletoe-infected trees in free-use privileges. These 

 privileges in the case of mistletoe-infected trees could be made 

 very liberal. The trees could be marked by the ranger during the 

 course of his yearly duties and to a certain extent he could cut 

 such trees for his own use. However, at the present time, it is 

 not possible to man even the more accessible forests with a force 

 of rangers to make a very appreciable headway. The ranger should 

 also be encouraged to make a study of the mistletoe situation, if 

 found necessary, in the region over which he may have control.^ 



' It is a good plan to use this method to graphically show the vertical and 

 horizontal distribution of all serious forest diseases in their relation to type of 

 stand, soil, climate, and topography. 



* During the past two years over 200 specimens of mistletoe (Razoumofskya), 

 representing all the species of economic importance in the West, have been 

 sent to the Laboratory at Missoula, Mont., for identification. 



^ To facilitate these studies the Laboratory of Forest Pathology, Missoula, 

 Mont., will furnish forms especially prepared for assembling field data on 

 mistletoe. These forms have already been extensively used on several Na- 

 tional Forests. 



