180 OUTLINES OF FORESTRY. 



greatest importance. But if the other conditions 

 of heat, light, and nourishment exist, almost any 

 soil will be found that will be the best fitted for 

 some few of the great variety of plants. 



The germ or seed is in all cases derived from a 

 plant similar to that which is produced when such 

 seed grows and bears fruit. 



The soil forms the plant's cradle ; in it the plant 

 spreads its roots, and obtains the water and min- 

 eral ingredients required for growth. 



The moisture and carbonic acid taken from the 

 air by a plant during its active growth form the 

 principal part of the plant's structure; the various 

 mineral matters taken from the soil form but a 

 comparatively small part of such structure. 



During active growth in the presence of sun- 

 shine, plants take in or absorb carbonic acid from 

 the air. Under the influence of sunlight, this car- 

 bonic acid, together with its associated water, is 

 eventually decomposed, the carbon and hydrogen 

 being retained, and the oxygen thrown off into the 

 air. 



The mineral matters in the soil must exist in 

 such conditions as will permit of ready assimi- 

 lation. 



Every section of country possesses a nationality 



