FOREST TREE SEED AND SEED COLLECTING 159 



come from the kiln they are quickly transferred to the "churn 

 room" or extracting room, which is kept at a temperature of from 

 77 to 86 F. The churn consists of a cylinder with its sides con- 

 structed of thin bars between which the cones cannot pass but 

 which permits the passage of the seed. By rotating the churn 

 the seed rattles out as the cones slowly pass to the exit at the 

 lower end. As the winged seed with such foreign matter as it 

 contains falls to the floor it is conveyed to the wing-removing 

 room. 



23. DETACHING THE WINGS 



When the seed is first separated from the cones it is mixed 

 with a great deal of foreign matter, often from two to five times 

 as much as the volume of the clean seed. This consists of bits 

 of leaves, twigs, resin, small stones, and fragments of cone scales. 

 The more or less firmly attached membranous wings on the seed of 

 most coniferous species must be detached before it is cleaned of 

 its foreign matter. The essential requirements in removing the 

 wings are freedom from injuring the testa or shell of the seed and 

 the complete removal of the wing. Two methods are practiced, 

 viz., the dry method and the wet method. 



24. The Dry Method. The simplest way to remove the 

 wings from coniferous seed when but a small amount is treated 

 is to rub it through a sieve in which the mesh is sufficiently small 

 to prevent the passage of the seed with the attached wings. In 

 many establishments the seed when brought to the cleaning room 

 is placed in partially filled sacks which are tossed about and beaten 

 with soft leather flails until the wings are detached. 



In modern seed-extracting establishments the seed as it comes 

 from the churn room is run through specially devised winging ma- 

 chines. These machines are in the form of cylinders of heavy 

 wire with the mesh sufficiently small to prevent the seed with the 

 attached wings from passing through. Kapidly revolving, stiff 

 brushes within, rubbing against the drum, quickly remove the wings 

 without harm to the seed. 



25. The Wet Method. In the wet process the seed with the 

 attached wings is spread out on a tight floor to a depth of from 

 4 to 6 inches and sprinkled with water until the whole mass is 

 slightly moist. Light leather flails are used to free the seed from 

 the wings. The only danger is in permitting the seed to remain 

 on the floor in a moist condition until fermentation takes place. 



