220 



STUDIES OF TREES 



at that time is much lighter, softer and more porous than 

 that formed later in the season, which is usually quite hard 

 and dense. These two portions, known as early wood 

 or spring wood, and late wood or summer wood, together 

 make up one year's growth and are for that reason called 



annual rings. Trees such 

 as palms and yucca do 

 not grow in this way, 

 but their wood is not 

 important enough in this 

 country to warrant a 

 description. 



If the end of a piece 

 of oak wood is examined, 

 a number of lines will 

 be seen radiating out 

 toward the bark like 

 the spokes in a wheel. 

 These are the medullary 

 rays. They are present 

 in all woods, but only in 

 a few species are they 



ver y prominent to the 



unaided eye. Theso rays 

 produce the " flakes " 

 or " mirrors " that make 

 quartersawed (radially 



cut) wood so beautiful. They are thin plates or sheets of 

 cells lying in between the other wood cells. They extend 

 out into the inner bark. 



While much may be seen with the unaided eye, better 

 results can be secured by the use of a good magnifying 

 flass. The end of the wood should be smoothed off with a 



FIG. 146. White Oak Wood. 

 (Magnified 20 times.) 



