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rapidly in the heartwood, with the grain, above and below the point of infec- 

 tion. The wood first becomes dark brown in color, and eventually white spots 

 appear, which increase in size until they fill the whole wood with a thin 

 white felt of mycelium. In trees like larch, with a distinct resinous summer- 

 wood, the fungus works in the springwood first, so that the summerwood 

 becomes separated in annual layers. When the internal decay has reached an 

 advanced stage, the fungus produces its fruiting bodies. These are brown 

 " conks " or " punks," which bear spores annually and sometimes attain an 

 age of 50 years. They do not appear on down timber. 



In order to prevent the spread of fungus diseases in the National Forests 

 all merchantable infested timber should be marked for cutting, and efforts 

 should be made to secure the removal of badly decayed trees by " free use." 



The exploitation of overmature timber and of trees that have been injured 

 will also lessen the risk of loss from this source. 



Silvical Reports 



Through the silvical reports of technical assistants 'the Forest Service is now 

 supplied with more detailed information upon silvical conditions in thirty of 

 the National Forests than has hitherto been obtainable. Although the reports 

 were prepared on short notice, they contain many valuable data, which have 

 been copied and filed by silvical topics in the Section of Compilation. The 

 information thus gained will be used in compiling silvical descriptions of species 

 to be published in separate leaflets. It is also the intention to publish later a 

 set of leaflets descriptive of the forest conditions prevailing in individual 

 National Forests. 



Reproduction on Cut-Over Land 



The Office of Silvics is about to undertake a study of logged-over areas. The 

 yellow pine and lodgepole pine types will probably be taken up first; and a 

 number of the older cuttings will be studied in order to determine what methods 

 of cutting are best adapted to secure successful reproduction and make the 

 torests as productive as possible. 



BRANCH OF PRODUCTS UTILIZATION. 



OFFICE OF WOOD. 



Timber Tests 



For the past year the Yale timber-testing station of the Forest Service has 

 been carrying on experiments to determine the effect of different methods of 

 drying upon the strength of wood. It has been decided to include in this 

 investigation methods of drying which involve high temperatures and air at 

 high pressure, the pressure being used to prevent the water in the wood from 

 reaching its boiling point. 



Statistics of Forest Products 



The statistics of forest products for the calendar year of 1906, which the 

 Forest Service and the Bureau of the Census have been collecting since Jan- 

 uary 1, are nearly complete and are being tabulated and compiled. The prin- 

 cipal item is, of course, sawed lumber, but in addition to this a census has been 



