16 INTRODUCTION. 



of field observations made while studying life zones and during thou- 

 sands of miles of travel, on foot and on horseback, especially in un- 

 frequented and little-known sections of the State. Doctor Merriam's 

 rare and accurate knowledge of Pacific trees renders the information 

 contributed exceptionally valuable. 



Special acknowledgment is due the American Museum of Natural 

 History, New York, for diameter measurements and corresponding 

 age determinations, taken from the Jesup Collection of North Ameri- 

 can woods, through the cordial cooperation of the director, Dr. H. C. 

 Bumpus." With these determinations, together with similar ones ob- 

 tained through personal field studies and from unpublished records 

 of the Forest Service, the author has been able to present statements 

 of the ages attained by practically all of the Pacific trees. 



It is difficult to abandon wholly the terse and exact language of 

 technical science and to convey in ordinary terms an accurate im- 

 pression of a tree's distinguishing characteristics. The writer has 

 endeavored to make this work simple and at the same time thoroughly 

 accurate. If it proves helpful at all in acquainting the uninitiated 

 with the characters and habits of Pacific trees, he will be greatly 

 encouraged in the preparation of the other regional floras designed to 



follow this part. 



George B. Sudworth. 



