EXTRACTING AND CLEANING FOREST TREE SEED. . - 3S 
The amount of broken cone scales depends partly on the species 
and partly on the treatment to which the cones are subjected during 
extraction. Seed of species whose cones are very brittle naturally 
contains more extraneous matter of this character. With most spe- 
cies, however, it is possible to avoid breaking the cones badly if they 
are shaken out rather than crushed out. The common method of 
putting heavy blocks of wood in the shaker with the cones is excellent 
for species whose seed is hard to extract or whose cones are tough. 
For other species, however, this method is undesirable, since it not 
only increases the difficulty of cleaning the seed, but is apt to injure 
it. It is advisable, therefore, to use no more violence than necessary, 
even if this makes extraction slower. The loss of time will be more 
than offset by the greater ease of cleaning. Twigs and broken needles 
can be largely kept out by screening the cones before drying is begun. 
The presence of broken seeds depends chiefly on the treatment of 
the cones. which has been discussed. Empty seeds are also present 
in nearly all samples. Their proportion depends partly on the 
species, but mainly on the season. In a poor seed year empty seeds 
are usually abundant; in a good seed year comparatively rare. They 
can be separated from good seed only by fanning. 
The presence of resin in seed depends mainly upon the species. It 
is probable, however, that crushing or overheating the cones increases 
its amount. It is certain that overheating, by softening and melting 
the resin, makes 1t much harder to remove. When the cones are 
heated to such an extent that resin sticks to the seed, it is practically 
impossible to remove it. Dust is always present to a greater or less 
extent. 
REMOVAL OF WINGS. 
The seed of all western conifers commonly handled have wings, 
which are usually, though not necessarily, removed when the seed 
is cleaned. Removal of the wings probably decreases the germinative 
power of seeds to a small extent. - It so greatly facilitates the ease 
with which they can be handled, however, that the practice is almost 
universal. In the pines, the entire wing may be detached from the 
seed with comparative ease, particularly if the seeds are first mois- 
tened slightly. With other species, however, the wings form part of 
the seed coat, and can be removed only by actually breaking them 
off. Moistening the seed is therefore of doubtful value. 
By flails——One of the oldest and commonest methods of removing 
Wings is to work the seed over in seamless sacks, the mouths of which 
are securely tied. The sacks are beaten with light flails, usually of 
leather, or kneaded with the hands and knees. Sometimes tlie sacks 
are tramped under foot for a few moments, but this method impairs 
the quality of the seed. With the pines, to which this method is 
particularly applicable, the wings are more readily removed if the 
