24 BULLETIN 275, U. S. DEPARTMENT OF AGRICULTURE. 



forest fires), composition, representation of species, ground cover, 

 possibilities of future logging operations as a first step toward regula- 

 tion, and local valuation of the species; more detailed notes of a 

 similar nature then describe the particular type and stand which is 

 the object of the study. 



When a new species is to be studied, trees of all sizes and all con- 

 ditions must be cut. It is absolutely necessary constantly to guard 

 against picking out trees either because they appear sound or because 

 they are liable to contain decay. According to the attitude of mind 

 of the investigator there will always be a tendency, conscious or sub- 

 conscious, to think of the final result and accordingly to choose par- 

 ticular trees for felling. The personal factor must necessarily 

 influence the result of the equation and can not be warned against too 

 emphatically. 



Correctness and accuracy in detail are the basis of any scientific 

 work worthy of the name. Where the one chief aim is to substitute 

 reliable figures for guesswork, to establish facts, from which con- 

 servative interpretation may derive certain working rules, observa- 

 tions and measurements can not go too far in detail and exactness. 

 On the basis of experiences in the incense-cedar studies, a printed 

 sheet was prepared, to be used in a loose-leaf binder of pocket size, 

 in which a set of standard notes was to be entered. Each sheet 

 contains the notes for one tree only. 



The first notes to be taken on a tree chosen for analysis are general; 

 they are taken before the tree is felled. Slope, exposure, soil com- 

 position, and moisture are taken for the individual tree; the next 

 notes concern the outward appearance of the tree, crown class, as 

 far as can be determined, condition of the bole, whether forked or 

 leaning, presence and degree of fire scars, resin flow on butt or bole, 

 swellings, sporophores of fungi, condition of the crown, development 

 and state of health; in short, all notes that can and should be taken 

 from the standing tree. During this time an assistant takes the 

 diameter breast high and sets the fellers to work. The notes on the 

 bole and crown are completed when the tree is down. They concern 

 the presence of mistletoes or needle diseases, witches' -brooms of any 

 kind, their number and relative importance, presence and extent of 

 lightning injury, condition of top, and similar data that might have a 

 bearing on the pathology of the species. It goes without saying that 

 the tree is felled at the regulation stump height of 18 inches, never 

 higher unless absolutely unavoidable. The assistant now measures 

 the height of the tree from the ground and counts the age at the 

 stump. This, of course, does not give the true age; but instead of 

 adding, more or less at random, a small number of years corresponding 

 to the height of the stump, it seems advisable to acoept the count 

 at the stump as the age. The fewer the figures based on an estimate 



