210 



WHERE PLANTS GROW 



peat. When dug out and dried, peat may be used as fuel. 

 Finally it may decay and make a vegetable soil known as 

 muck. When thoroughly decayed, plants become vege- 

 table mold or humus. New plants grow on peat or muck, 

 and the accumulations year by year tend to raise the level 

 of the bog, and the surface finally becomes so high as 

 to support plants of the high lands. An important agent 

 in the formation of peat bogs is sphagnum moss. New 

 moss grows on the old, and the bog becomes higher as 

 time goes on. (Fig. 374.) 



376. A landscape devoid of vegetation. Western United States. 



365. Plants Contribute to Scenery. — Aside from sky 

 and air, natural scenery depends chiefly on two things: the 

 physical contour of the earth; the character of the vegeta- 

 tion. Contrast the aspect of winter and summer scenes as 

 expressed in vegetation. (Fig. 375.) Imagine any land- 

 scape with which you are familiar to be devoid of plants. 

 Compare Figs. 376 and 377. 



Review. — What is meant by environment? By habitat? Flora? 

 What determines where plants shall grow? What is an aquatic plant? 



