TBM STBDOGLE FOB EXISTENCE 383 



Whenever plants are destroyed and ground is thereby- 

 unoccupied, there is a rush for the place which 

 may be likened to the rush of men to a newly 

 opened and fertile territory. 



482. There results a most confused and conglom- 

 erate population ; but in time certain elements 

 have persisted, and a few kinds of plants occupy 

 the area. A clearing is occupied by the wildest 

 confusion of growths, but, if fire and cattle do not 

 enter, a more or less uniform forest is the outcome. 

 If fire devastates the area, the battle is renewed. 

 If cattle invade, a pasture is the result ; and, in 

 the North, the plant which finally gains the vic- 

 tory, — because the one which can withstand the 

 grazing,— is June -grass. The farmer plows his 

 land and kills the plants. A horde of weeds is 

 waiting. If he sows grain, the land is soon occu- 

 pied and the weeds have little chance ; but if his 

 crops occupy only half the ground, — as with beets, 

 potatoes, and melons, — the battle wages the entire 

 season. If he were to leave his well -subdued 

 plowed land to care for itself, the battle would 

 wage most fiercely for a year or two, but the ob- 

 server would see that the fortunes change, for 

 while ragweed might hold the field one year, mul- 

 lein might hold it the next, and June -grass might 

 again win the final victory. If his plowed land 

 were full of the roots of briars and other wild 



