9 



Grateful acknowledgment is tendered to Hon. Robert S. Conklin, 

 Commissioner of Forestry, at whose suggestion the bulletin was 

 started and under whose careful and constant direction it was de- 

 veloped. Especial acknowledgment is due to Hon. I. C. Williams, 

 Deputy Commissioner of Forestry, who read the entire manuscript, 

 for his inspiration, many valuable suggestions and criticism. Thanks 

 are due to George H. Wirt, Forest Inspector, and Prof. George A. 

 Retan for their assistance and valuable suggestions. 



I take pleasure in expressing my gratification to all others who 

 have in any way assisted in this publication, especially the students 

 of the Pennsylvania State Forest Academy for their co-operation, 

 and the graduates for their assistance in collecting data concerning 

 the distribution of trees in this State. 



J. S. ILLTCK. 



