Testing Farm Seeds. 



343 



lead merely to providing for foreign matter by sowing a larger quantity 

 of seed. 



The seed of most of tlie farm crops can be recognized with certainty 

 under careful examination as to its particular kind. Seed of different 



Fig. 11. — Mixture of seeds of awnless brome-grass (a), meadow fescue (b), Eng- 

 lish rye-grass (c), and chess, or cheat (il). The brome-grass seeds are dis- 

 tinguished by their greater length and flattened form. The seeds of chess 

 (d) are somewhat cylindrical, due to being folded lengthwise. They are thus 

 thicker than the awnless brome-grass seed and sometimes are awned. (En- 

 larged.) 



varieties of a kind as a rule can not be distinguished in this way. For 

 example, red clover seed can be distinguished from other seeds, but the 

 medium and mammoth varieties of red clover can not be distinguished by 

 their seeds. Seeds of varieties of individual kinds of plants usually 



must be grown to insure vari- 

 etal determination. This is 

 not a part of the usual seed 

 test. 



The first object of the test, 

 excepting with respect to va- 

 rieties, is to find out if the 

 seed is true to name. 



« 



The seed of certain farm 

 crops is rarely free from all 

 impurities. Miscellaneous im- 

 purities may appear or some one kind of foreign seed may be present as 

 an adulterant. Old seed of the same kind as the crop seed may constitute 

 an adulterant, a fact which becomes apparent in the germination test. 



^ -^.^^^J 



a 



Fig. 12. — Seeds of flax dodder (b double, c 

 single) and of flax (a), showing relative 

 sizes. (Enlarged.) 



