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BOTANY. 



Growth. 



Synopsis. 



An increase in the bulk or size of the plant. 



(Parts of the plant become longer and stouter.) 



Growth in length of the root takes place most actively a few 

 millimeters back from the tip. 



The region of elongation of the root changes as the root be- 

 comes longer. 



Growth in length is the result of the elongation of the newly 

 formed cells [the formative region (i.e., where new cells are 

 formed; is in the root .tip]. 



The stem grows in a similar way, but the region of elongation 

 extends over a greater area than in the root. 



As a result of the increase in the size of plants by growth, 

 great force is exerted, sufficient to move considerable amounts 

 of hard earth ; or, in the case of trees, to even split rocks, 

 or to lift up during growth the entire plant material in 

 trunk and branches. 



The energy of growth during the season, or during the life of 

 an annual, varies. It is low at first, as manifested by the 

 small size of the members, then it increases to a maximum, 

 then decreases. 



Material and apparatus. Seedlings of squash, or pumpkin, or peas, etc., 

 grown in a germinator free from earth. The seeds should be started a 

 week to ten days before they are wanted, so that the roots will be about 

 3cm to \cm long. (See demonstration 2 for preparing seedlings.) Sev- 

 eral moist chambers; large corks upon which some of the seedlings can be 

 pinned. 



India ink and crow-quill pen for marking the roots. 



Seedlings grown in soil in pots with the stems just appearing above 

 the soil. 



Potted begonias; entire corn plants (may be pressed and preserved dry); 

 or small but mature sunflower plants (also may be preserved dry). 



