6 BEGINNERS' BOTANY 



Struggle for existence and adaptation to conditions are 



among the most significant facts in nature. 



The sum of all the conditions in which a plant or an ani- 

 mal is placed is called its environment, that is, its surround- 

 ings. The environment comprises the conditions of climate, 

 soil, moisture, exposure to light, relation to food supply, 

 contention with other plants or animals. The orgajiism 

 adapts itself to its eiivii'onmcnt^ or else it weakens or dies. 

 Every weak branch or plant has undergone some hardship 

 that it was not wholly able to withstand. 



Suggestions. — The pupil should study any plant, or branch of a 

 plant, with referent'e to the position or condition under which it 

 grows, and compare one plant or branch with another. With animals, 

 it is common knowledge that every animal is alert to avoid or to 

 escape danger, or to protect itself. 2- It is well to begin with a 

 branch of a tree, as in Fig. 1. Note that no two parts are alike (Chap. 

 I). Note that some are large and strong and that these stand far- 

 thest toward light and room. Some are very small and weak, barely 

 able to live under the competition. Some have died. The pupil can 

 easily determine which of the dead branches perished first. He should 

 take note of the position or place of the branch on the tree, and 

 determine whether the greater part of the dead twigs are toward the 

 centre of the tree top or toward the outside of it. Determine whether 

 accident has overtaken any of the parts. 3. Let the pupil examine 

 the top of any thick old apple tree, to see whether there is any 

 struggle for existence and whether any limbs have perished. 4- If 

 the pupil has access to a forest, let him determine why there are no 

 branches on the trunks of the old trees. Examine a tree of the 

 same kind growing in an open field. 5. A row of lettuce or other 

 plants sown thick will soon show the competition between plants. 

 Any fence row or weedy place will also show it. Why does the 

 farmer destroy the weeds among the corn or potatoes? How does 

 the florist reduce compet jn co At? icwest terms! what is the result? 



