Distribution and Propagation. 43 



ence of which we could not otherwise 

 account for. 



Moreover, farmers sometimes test by 

 local trial the suitability of the various sorts 

 of farm seeds that are to be obtained in 

 foreign countries. This work has its dan- 

 gers as well as its benefits. In the old 

 world, as in the new, it is almost impos- 

 sible to buy seed in the open market entirely 

 free from the seeds of foul weeds. When 

 foreign seeds are distributed through the 

 medium of our agricultural experiment sta- 

 tions, a considerable degree of assurance is 

 furnished the farmer that he w^ill get pure 

 seed ; but it would probably be claiming too 

 much for those stations to say that, even 

 when the farmer takes this precaution, there 

 would be no danger. As long as farm 

 seeds are bought in the open market, there 

 will be some danger that the seeds of nox- 

 ious w^eeds will be brought to our farms by 

 means of them. 



2. Farm live stock. Very frequently weed 

 seeds are introduced upon a farm by being 

 carried in the hair or wool of live stock 

 brought from other localities. Sometimes 

 the w^eed seeds cluster about the hair of the 

 mane and tail. When the animals are given 



