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THE ROYAL SOCIETY OF CANADA 

 Dockage on Cars Received at Terminal Elevators 



' Crop year Sept. Ist-Aug. 31st. 



2 Total dockage is expressed in tons and pounds, 

 represents pounds. 



The number after the dash 



Variations in Composition of Screenings 



The weed seed content of screenings varies considerably, depend- 

 ing on the kind of grain cleaned, place of growth and season or climatic 

 conditions. Most of the screenings accumulating in the elevators at 

 the head of the lakes are obtained from the cleaning of wheat. Dock- 

 age is set on only occasional cars of oats and barley, while the total 

 quantity of flax handled is comparatively small. 



The seeds of false flax (Camelina sativa (L) Crantz and C. 

 dentata Pers) which are the commonest impurities in flaxseed are 

 rarely found in other grain. Flaxseed screenings also contain a high 

 percentage of broken pieces of flax. These screenings are kept separate 

 from other grain screenings in some elevators and command a higher 

 price on account of their oil content. An elevator handling much flax 

 and mixing all its screenings together will have screenings widely 

 different from one where flax is not handled. 



Seasonal or local climatic conditions have a profound effect on 

 the amount of weed seed impurities occurring in grain and also on the 

 relative prevalence of the seeds of different species. 



