YIELD OF SEED. 685 



Larch-seed, when freed from the cones, is mixed with 

 pieces of wood and scales of various sizes, and any amount 

 of dust, from which it must be cleaned. The sifting process 

 is therefore tedious and the workmen must show much 

 patience. The seed is separated from refuse either hy 

 means of hand-sieves, or by fly-wheels, or by placing it on 

 water in a tub; the pieces of wood and scales sink to the 

 bottom, whilst the seeds float on the surface and are then 

 scooped off and dried, the dried seeds finally passing through 

 a corn-sifter. 



In Keller's seed-depot a small mill is used for removing the 

 wings from larch-seed, the grinders being made of vulcanised 

 caoutchouc and as far apart as the length of the seeds ; thus 

 the wings are removed by friction. A fly-wheel working 

 under the exit-funnel separates thoroughly the wings, dust 

 and worthless seed, from the good seed. 



6. Ifmfkiiiii Stlrrr-lir ('<>n<'S, <'tc. 



The cones of silver-fir usually fall to pieces on their way to 

 the seed-husking establishment ; the seeds are separated from 

 the large cone-scales by sieves. The wings are united to the 

 seeds and are removed by friction, or by trampling or beating 

 them in sacks. Similarly the seeds of Douglas-fir, Douglas 

 and Weymouth pines are cleaned. The cones of thuyas and 

 cypresses open readily when exposed to the sun, and the little 

 seeds are sifted free from the scales. 



7. Net Yield of Seed. 



The net yield of seed obtained from a certain quantity of 

 cones depends on several circumstances. The system of 

 husking followed is most decisive in this respect ; then the 

 condition of the cones (whether harvested in autumn, mid- 

 winter, or in dry, spring weather, after some of the seeds have 

 left the cones). The size of the cones and the number of 

 seeds they contain vary in different years, for in really 

 good seed-years cones are often smaller than usual and yet 

 contain more than the usual number of seeds. Lastly, the 



