



Pholo: F. R. Hinkins & Son. 



SECTION OF AN OAK-TREE 



Wood formed in spring is light and open in texture; wood 

 tormed in summer is dark and close-grained. From the edge 

 of one dark zone to the edge of the next is an annual ring which 

 marks one year's growth. By means of these rings it has been 

 possible to ascertain the age of some red-wood trees to be over 

 2,000 years. The thickness and structure of the ring give clues 

 to the climatic conditions which obtained when it was formed. 



Pholo: F. R. Hinkins & Son. 



CROSS SECTION OF THE STEM OF THE BUTCHER'S 

 BROOM 



The dark circles are the bundles of conducting tubes which 

 provide for the passage of water and food-stuffs through the 

 plant, the clear spot near the edge of each bundle being the 

 largest water-conducting wood-vessel. Between the bundles 

 can be seen the large cells which make up the ground tissue; 

 while to the outside a darker ring marks the position of a band 

 of strengthening fibres. 



