THEIR ANCIENT LINEAGE 



they resist the storms of every season, the winter's 

 cold, the summer's heat. They are a most wonder- 

 ful expression of life, year by year adding to their 

 dimensions — often through centuries — flourish whilst 

 generations of mankind come and go, reach their 

 optimum, produce seeds to perpetuate their kind, 

 and finally obey the law inevitable: die, and give 

 place to others. Their structure built of myriads 

 of minute cells piled on and around each other and 

 differentiated into tissues of varying thicknesses and 

 forms as best adapted to the work each has to per- 

 form in the life economy of the whole organism. 



The big roots firmly anchor the tree to the earth 

 and give off tiny rootlets that absorb water and 

 various food salts in solution which are carried up- 

 ward through special tissues to the leaves. The 

 leaves — the lungs and chemical laboratories of the 

 tree — breathe in from the air during daylight a gas 

 deleterious to man (carbon dioxide), break it up, ex- 

 hale a part as pure oxygen essential for the life of the 

 animal kingdom, and combine the remaining carbon 

 and oxygen with the water and food salts supplied by 

 the rootlets into simple forms of sugar, in which man- 

 ner they are immediately available as food to nourish 

 the tree's growth in all its complicated parts. So 

 much of these sugars not at the moment wanted is 

 converted into forms of starch and stored away for 



7 



