50 i^v ccas. ^ 



p. Kailzvays. Railways seem to be a 

 wonderfully effective agency in the distri- 

 bution of weeds, by means of the fodder 

 supplied to the horses and other animals 

 used in constructing them, and the bedding 

 of cars in which live stock is carried. The 

 litter with which these cars are supplied 

 frequently contains noxious weed seeds ; 

 these, falling to the ground, grow in the 

 soil along the track and commence to repro- 

 duce their kind. A third explanation is 

 found in the fact that oftentimes the weed 

 seeds contained in the grain that is being 

 shipped escape through leaks in the cars 

 and fall to the sides of the track, where they 

 often find conditions quite suitable to their 

 germination. In these and other ways, the 

 railways of the country have become largely 

 responsible for the introduction of new and 

 troublesome weeds into localities where pre- 

 viously they were unknown. 



10. Birds. Birds carry weed seeds to 

 great distances. A sprig of a plant on 

 which the seeds have not left the capsules 

 in which they grew is caught up by a bird 

 and carried to some distant place where 

 the food which its seeds afford can be 

 enjoyed without molestation. Some of the 



