HOW TREES GROW 23 



life. It is made up of carbon, hydrogen, and 

 oxygen. The carbon is drawn from the car- 

 bonic^acid gas absorbed by the leaves ; the hy- 

 drogen comes from the soil water soaked up by 

 the roots ; some of the oxygen comes in by way 

 of the roots, the balance is breathed in by the 

 green stems and the foliage. 



Miss Going, in her book With the Trees, tells 

 us that: "The newly made starch in leaves 

 appears in tiny grains inside the chlorophyll 

 bodies or close beside them. It does not re- 

 main there and grow into larger starch grains, 

 but with the withdrawal of sunlight it seems to 

 melt away. It has been changed into fluid glu- 

 cose, and this travels slowly along, passing 

 through cell wall after cell wall, till it reaches 

 some growing part of the tree, where it is used 

 at once, or some resting place where it is turned 

 into starch again, and stored away to meet the 

 needs of the future. In spring all the starch 

 which the leaves can make is changed to glucose, 

 and used immediately, for growth. But in lat- 

 ter summer the tree puts it by. It may be saved 

 in wood or pith to feed next spring's blossoms 

 and shoots, or it may be packed into seeds and 

 support the tree's children during their in- 

 faincy." 



The wood of a tree is not active. Neither is 



