Poor Seed 



93 



care in cultivation and in fertilization. Old seed 

 produced in a favorable season may be preferred to 

 fresh seed but of an inferior quality, produced in a 

 bad season. 



Weight and Color of Seed. As a rule, light weight 

 seed is inferior to heavy seed of the same variety. 

 The weight of the seed is influenced by culture and by 

 imperfect fertilization which results in minute and 

 weak embryos. The weight of seed may be readily 

 determined by the water method. Place the seed in 

 a tumbler filled with water. After shaking and let- 

 ting it stand for a few minutes, the heavy ones sink 

 and the light ones float. Using this method, Stone 1 

 has shown that the heavy sinking seed give a higher 

 per cent, of germination than the lighter (see Tables 10 

 and n). 



Table io 

 Showing the Results of Seed Separation by the Water Method 



Name of Seed 



Lettuce 



Onion 



Onion 



Lettuce 



Onion 



Average 



Per Cent, of Increase in 



Germination of Light 



over Heavy Seed 



32. 



17. 

 142. 

 IOO. 



17- 

 61. 



1 Stone, G. E., Massachusetts Agr. Expt. Sta. Bui. 121 :3-i4, 1908. 



