Spruce stands should never be severely thinned, as the shallow root 

 system renders the trees liable to be thrown by the wind. This dam- 

 age is especially great in exposed situations. In case such destructive 

 agencies as insects or fungi appear, specimens, accompanied by an 

 account of the character of the injury, should be sent to the Depart- 

 ment of Agriculture for identification and recommendations for their 

 control. 



Approved. 



JAMES WILSON, 



Secretary. 

 WASHINGTON, D. C., November 24, 1906. 



[Cir. 65] 



o 



