Alfalfa in Kansas. 



207 



FIG. 185. Seed pods of Sweet clover, 

 magnified. 



Fia. 186. Seed pods of Pur clover, 

 magnified. 



Fia. 187. Seed pods of Yellow Trefoil, 

 magnified. 



The tiny embryo stem, which lies partly below and partly above the 

 junction of the two cotyledons, or seed leaves, now begins to grow. The 

 part below the seed leaves (called the hypocotyl) grows very fast so 

 fast that it curves up in a loop, while the two seed leaves are still held 

 fast to the buried seed. By its growth it pulls the seed leaves out and 

 pushes its bent neck up through the soil, just like a bean, dragging the 

 seed leaves after it, and germination is then completed. 



The vitality or germinating power of alfalfa seed is easily tested. 

 Take two lots of one hundred seeds each at random from a sample, 

 exercising care not to choose or select the best-looking seeds, but simply 

 taking them as they come, rejecting all trash and broken seeds. Take a 

 piece of clean white blotting paper, 5 by 8 inches in size, folded across 

 the middle, and well moistened in clean, warm water. Lay a lot consist- 

 ing of one hundred seeds upon one of the halves of the blotter, scattering 

 them out over the surface so that they will not touch one another; fold 

 the other half of the blotter down, and place the folded blotter between 

 two ordinary dinner plates, the upper one inverted over the lower to 



