Flailed seed should be cleaned thoroughly with sieves and fanning mills to remove the inert matter and immature pods before it is sown or offered for sale on the market. It is recommended that whenever possible unhulled seed be run through a clover huller to hull the seed or through an Ames hulling and scarifying machine to remove the hulls and to scarify the seed. By this process the outer coat of the seed is scratched or broken. The scarifying increases the percentage of germination by facilitating the entrance of moisture. [Illustration: Fig. 13.--Thrashing sweet clover with a grain separator. Note the large sleds used for handling the plants from the field to the thrashing machine.] THE GRAIN SEPARATOR. A grain separator (fig. 13) is used more than any other machine for thrashing sweet clover. This is because more grain separators than clover hullers are found in localities where sweet clover is grown and because the ordinary clover huller will not handle a large growth of sweet clover satisfactorily. When the grain separator is operated carefully no trouble should be experienced in removing the seed from the plants, but it is necessary to make certain adjustments if the seed is to be hulled. The adjustments required will vary somewhat with the make of machine and the dryness of the crop. The riddles should be adjusted or changed so they will handle sweet-clover seed properly. Alfalfa or red-clover riddles will answer this purpose. The speed of the fan should be decreased, so the seed will not be blown over, and this usually will be accomplished when the speed is reduced to about one-half that used in thrashing grain. The number of rows of concave teeth which should be used will vary with the dryness of the plants and somewhat with their size. When it is not desired to hull the seed, one or two rows of concave teeth will be sufficient. Some operators believe that one or two rows are sufficient to hull 40 to 50 per cent of the seed when the plants are very dry. Those are exceptional cases, and hulled seed should not be expected unless more rows of concave teeth are used. If hulled seed is desired it is recommended that a full set be used and that these be set to run closer to the cylinder teeth than is customary when thrashing grain. Some operators replace two rows of the smooth, concave teeth with corrugated teeth. This practice is recommended wherever possible, as the corrugated teeth will facilitate greatly the hulling of the seed. Even where these changes are made, only a small percentage of the seed will be hulled if the pods are damp. If the plants have been permitted to make a very large growth the machine may clog unless the number of rows of concave teeth is reduced. Clogging may be overcome for the most part by feeding the bundles to the machine slowly. This precaution is necessary regardless of the size of the plants if the seed is to be removed properly and hulled.