156 



SCHOOL AND HOME GARDENING 



6. Age of Woody Plants. — The older pupils or other persons 

 may bring to school cross-sections of wood sawed from trees, posts 

 or logs. Studies may be made of these, counting the number of- rings 

 of hard wood which alternate with rings of softer wood. Note the 

 lines running in the direction of the spokes of a wheel. These ' 

 are rays of different tissue running toward the bark. 



In ordinary seasons of growth, a hard ring and a soft ring 

 of wood are added each year. The age of a tree may be 



a p p r X i mately determined by 

 counting the layers or rings of 

 hard wood between the center and 

 the bark. The new rings are 

 added each year outside the older 

 ones, and the bark is pushed out- 

 ward, year by year. This plan of 

 growth is found in all native trees 

 of the north and temperate zones. 

 " Quarter-sawed " lumber is 

 cut first through the center par- 

 allel to the " spokes " or rays run- 



FiG. 88.— ^Trees should be • n ,^ , rm i x* 



pruned before they are reset. (New nmg trom the Center. 1 he Deautl- 



ersey a lon.j ^^j quarter-sawed effect of lumber 



is produced by the exposure of the ray tissue on the surface. 



7. Age Shown in Twigs. — ^Let each pupil have a branch of 

 maple or other tree in winter condition. This should be examined 

 closely to see the location of the buds. Note that they are found on 

 the newest growth and seldom or never back of that. Each twig 

 has a terminal bud covered with bud scales. The bud is to form 

 the new shoot next season. As the shoot grows from the bud, the 

 outside scales drop off, leaving scars which remain for many years 

 at the base of each new shoot. Now, begin at the end of any twig 

 and look back along it until the first ring of bud scale scars is found. 

 This is where the growth began last year. Feel back again and find 

 the beginning of another year's growth. Thus trace the twig back 

 as far as you can and name the calendar year of each portion of 

 growth. Note how much more growth was made some years than 

 others. Can you account for this? Some seasons there would be 

 a number of side branches formed from lateral buds. Perhaps other 



