Distribution and Propagation. 55 



single season ; and by the latter many weeds 

 are continually spreading and occupying 

 wider and wider areas. These powers of 

 reproduction enable weeds to multiply rap- 

 idly, without the aid of any of the agencies 

 previously mentioned, when once they have 

 been brought into new centers by one or 

 another of these agencies. 



With the agencies that have been men- 

 tioned continually engaged in the work of 

 weed distribution, and also with others that 

 have not been mentioned, the task of the 

 eradication of weeds at first thought seems 

 appalling. While the power of weeds to 

 multiply and spread is very great, the power 

 of man to destroy them is greater, unless 

 this limitless power is allowed to pass unu- 

 tilized with the rush of crowding oppor- 

 tunities. While it is true that there can 

 be no discharge in this war, it is equally 

 true that there can be no defeat for the 

 resolute tiller of the soil who persistently 

 and constantly strives to keep his farm 

 clean. 



It has already been mentioned that over 

 some of these agencies of weed distribu- 

 tion we can exercise but little or no control. 

 These are the agencies of nature — as wind 



