Distrioutwn and Propagation. 51 



seeds thus carried fall by the way, and 

 start new centers of weed distribution. The 

 instinct for nest-building not infrequently 

 leads to similar results. In this fact we 

 find an explanation of the unexpected 

 appearance of weeds along the edges of 

 forests, and in other localities where the 

 soil has never been subjected to cultivation. 



//. IVild animals. Certain wild animals 

 are the local distributors of weeds, for, 

 being fond of a varied diet, they include 

 the seeds of certain weeds in their list of 

 desirable foods. Sometimes they bury or 

 store away weed seeds when layng up their 

 winter's supply. They also use the foli- 

 age and stems of weeds in building their 

 lairs or nests. When gathering these, they 

 sometimes attempt to carry loads which are 

 more than they can manage, and so leave 

 a part upon the way, for which they may 

 not return. The seeds that are thus dis- 

 tributed here and there on the soil, or are 

 dropped at the mouth of the burrow, or left 

 unconsumed in the nest, spring at length 

 into vigorous life, and commence again the 

 w^ork of weed distribution. 



12. Waters. Few agencies are more 

 potent in the distribution of the seeds of 



