APPENDIX. 293 



thin glass, moistened and covered with another piece of glass, they may be 

 examined by holding them toward the light. 



Finding, on examination with the magnifier, that it contains pores, we 

 know it is not coniferous or non-porous. Finding no pores collected in the 

 spring-wood portion of the annual ring, but all scattered (diffused) thru 

 the ring, we turn at once to the class of "Diffuse-porous woods." We now 

 note the size and manner in which the pores are distributed thru the ring. 

 Finding them very small and neither conspicuously grouped, nor larger 

 nor more abundant in the spring-wood, we turn to the third group of this 

 class. We now note the pith rays, and finding them neither broad nor con- 

 spicuous, but difficult to distinguish, even with the magnifier, we at once 

 exclude the wood from the first two sections of this group and place it in 

 the third, which is represented by only one kind, cottonwood. Finding the 

 wood very soft, white, and on the longitudinal section with a silky luster, 

 we are further assured that our determination is correct. We may now 

 turn to the list of woods and obtain further information regarding the oc- 

 currence, qualities, and uses of the wood. 



Sometimes our progress is not so easy; we may waver in what group 

 or section to place the wood before us. In such cases we may try each of 

 the doubtful roads until we reach a point where we find ourselves entirely 

 wrong and then return and take up another line ; or we may anticipate 

 some of the later mentioned features and finding them apply to our specimen, 

 gain additional assurance of the direction we ought to travel. Color will 

 often help us to arrive at a speedy decision. In many cases, especially with 

 conifers, which are rather difficult to distinguish, a knowledge of the locality 

 from which the specimen comes is at once decisive. Thus, northern white 

 cedar, and bald cypress, and the cedar of the Pacific will be identified, even 

 without the somewhat indefinite criteria given in the key. 



