ON LAWN BEAUTIFICATION 



case are usually small and are provided with a 

 hard coating so that they are not destroyed by di- 

 gestion in the bird's or animal's stomach, but are 

 carried great distances and on reaching the ground 

 are usually in best condition to germinate. 



Most weed seeds have the ability to retain their 

 vitality for a long time. Farmers who have plowed 

 fields deeply have sometimes noticed that a certain 

 weed which was present the year before plowing 

 disappeared entirely for two or three years only 

 to reappear again later. This was due to the fact 

 that the seeds were placed by the deep plowing 

 several inches below the surface, and when the soil 

 was plowed deep again they were brought nearer 

 the surface. In some cases, seeds have been known 

 to retain their vitality for twenty years or more. 



Although weed seeds are provided with many 

 more contrivances to secure a wide distribution 

 than those here mentioned, this is not the only pro- 

 vision for their perpetuation. Living as they do 

 among many discouragements and difficulties it 

 has been necessary for them to provide protection 

 for the plants themselves against unfavorable 

 weather conditions and against animals. Some 

 weeds have the ability to withstand long and severe 

 drouths while others are able to grow where there 

 is a superabundance of moisture. Some are able 

 to withstand extremely low temperatures. 



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