CHAPTER II 

 GROWTH AND NUTRITION 



THE well ripened seed, if kept dry, will remain dor- 

 mant, resistant to various injurious influences for several 

 years and still retain its vitality. After the second 

 year, however, there is a steady decrease in viability, 

 and after eight or ten years few or no seeds will germi- 

 nate. 1 



13. Germination. On the addition of water, and 

 with the proper temperature, the aleurone and starch 

 grains swell, the seed increases greatly in size and becomes 

 softer, and germination begins. As before stated (8), 

 the foundations of the first or seminal roots are laid 

 before germination in the hypocotyl. Each of these 

 seminal roots breaks through the coleorhiza independently 

 and becomes surrounded by a portion of it as a sheath. 

 Previously root-hairs from the coleorhiza itself fasten the 

 seed to the soil. The upward extension of the embryo 

 axis or mesocotyl is virtually the first internode of the 

 new plant, and is well developed in oats. In wheat it 

 is little developed, and not at all in barley. The coleop- 

 tile, inclosing the plumule pushes to the surface, and then 

 opens to allow the 2 to 4 leaves of the latter (the plumule) 

 to emerge. 



1 Of course, all stories about the growth of wheat, emmer, 

 and barley seeds that have lain with mummies in Egyptian pyra- 

 mids during many centuries have no basis in fact. 



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