48 



Other seeds are spread by the wind, like dandelion, 

 having hair-like parachutes which render them 

 buoyant. (Others are provided with menibrarous 

 wings Some, for instance the tumi)le-weeds, dis- 

 tribute their seeds by curling into ball form, when 

 dr}^ In the fall breaking off near the root and are 

 blown about here and there by the wind, scattering 

 seeds as they go. Russian thistle is an example of 

 this. The heads of some grasses, like old-witch- 

 grass, have this same peculiarity. Some plants retain 

 their seed until snow is on the ground and then the 

 wind blows the seed over the surface of the snow. 

 Along the railroad, weeds are also scattered by dirty 

 stock-cars, by cattle and in hay and straw. Leaky 

 grain-cars drop much seed. On the slow track on 

 grades, especially the eastbound track bringing grains 

 from the west, there is usually a mat of weeds, 

 grains, etc. This is natural, as the trains running- 

 slow do not blow away the seed dropped by them. 



The question of the destruction of weeds is much 

 easier to speak about than to carry out. The pre- 

 vention of the introduction of weed-seeds can hardly 

 be accomplished. It would be recommended, however, 

 that all stock, vegetable and hay cars be thoroughly 

 cleaned and kept clean ; to be onh' cleaned at certain 

 specified places, at division termini. All refuse hay, 

 manure and dirt should be burned at these points. 

 Grain cars should be carefully watched at time of 

 loading to prevent leakage and kept in good repair. 

 Perennial weeds, especially those with underground 

 stems or large roots, must Vje kept cut close to the 

 ground to starve out the underground part. The 

 taking away of the leaves, deprives the plants of the 

 carbon dioxide of the air and so starves them out 

 gradually. Salt. kerosene, strong sulphuric or 

 hydrochloric or carbolic acid may be used with most 

 excellent result on the more pernicious ones growing 

 in patches. 



Weeds caused by certain conditions of the soil. 



