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INTRODUCTION TO BOTANY 



means of roads helps to keep small fires from spreading, but 

 in warm dry weather a coniferous-forest fire under full head- 

 way makes such leaps that it is seldom stopped until it reaches 

 extensive clearings or rivers or other large bodies of water. 



FIG. 99. Oak trees growing in the open 

 White oak at the left and red oak at the right 



5. Parasitic fungi and the saprophytic kinds which cause the 

 decay of fallen trunks and branches or felled trees (figs. 182 

 and 199) should be burned, when this is not too expensive and 

 when it can be managed without danger of starting forest fires. 



