Habits of Grozvth. 63 



cheat, while among our cultivated crops, 

 winter rye and winter wheat are winter 

 annuals. More commonly, annuals begin 

 to grow toward the approach of spring. 

 Common examples of summer or ordinary 

 annuals are ragweed, foxtail and pigweed, 

 while among our cultivated crops we have 

 corn, oats, flax, spring wheat, and many 

 others. It follows, then, that as annual 

 weeds can live but a single season, if the 

 plants of any particular sort of weeds of 

 this class on any farm are prevented from 

 ripening their seeds year by year through 

 successive years, the time must come sooner 

 or later when that sort of weed will be 

 completely destroyed on that farm. This is 

 true whatever may be the means that may 

 be adopted to prevent the seeds from ripen- 

 ing. In fact, the weeds would all be 

 destroyed in a single year were it not that 

 many seeds have great power to resist 

 decay, and many remain in the soil for 

 many years without their vitality being lost 

 or even impaired. Some seeds of this class 

 of weeds, as those of wild mustard, retain 

 their vitality for an incredible length of 

 time ; so that whenever they are brought 

 sufificiently near the surface by cultivation, 



