The Authors 



MARVIN W. FOILES is a Silviculturist at the Intermountaiti Station's 

 Forestry Sciences Laboratory in Moscow, Idaho. Since joining 

 the Forest Service in 1948, he has been engaged in silvicultural 

 research in the northern Rockies. From 1948 to 1957, he work- 

 ed in the western white pine project in Spokane, Washington. 

 From 1957 to 1967, he conducted research in the Silviculture of 

 Ponderosa Pine and Interior Douglas-fir project in Boise, Idaho. 



JAMES D. CURTIS retired from the Intermountain Station in 1966 as 

 leader of the Silviculture of Ponderosa Pine and Interior Douglas- 

 fir research project in Boise, Idaho. He joined the Intermountain 

 Station staff in 1947. He is a graduate of the University of Brit- 

 ish Columbia and Harvard University. 



