(JUoun^atn {paxtiB 



with sod that tree seeds find no opening, and 

 grass thus holds possession for decades, and, 

 in favorable places, possibly for a century. 



Trees grow up around these areas and in due 

 time the grassy park is surrounded by a forest. 

 The trees along the edge of this park extend 

 long limbs out into it. These limbs shade and 

 kill the grass beneath. Tree seeds sprout where 

 the grass is killed, and these seedlings in turn 

 produce trees with long limbs reaching into the 

 park. These shade and smother more grass and 

 thus advance the forest another limb's length. 

 Slowly but surely the park is diminished. 



Struggling trees may sometimes obtain a place 

 in advance of the others or a start in the centre 

 of the park, and thus hasten the death of the park 

 and speed the triumph of the trees. A mere in- 

 cident may shorten the life of a park. A grizzly 

 bear that I followed one day, paused on a dry 

 point in a park to dig out some mice. In reach- 

 ing these he discovered a chipmunk burrow. 

 By the time he had secured all these he had 

 torn up several square yards of sod. In this 

 fresh earth the surrounding trees sowed tri- 



235 



