THE CLOVERS 229 



Seed Germination 



Determine the per cent of viability of twenty-five seeds 

 placed in germination without preliminary treatment, 

 allowing seven days for germination. 



Treat twenty-five other seeds from the same lot with 

 sulphuric acid for twenty minutes. Determine the 

 percentage of viability and compare quickness of germi- 

 nation with that of the untreated seeds. 



Root Nodules 



Dig up a thrifty clover plant carefully. Wash the 

 soil from the roots. See the little yellowish nodules on 

 them. 



Make a drawing of a root showing some of the nodules. 



Read pages 275-281, Farm Friends and Farm Foes. 



Clover Soils 



Bring to school a half pint of soil in which clover 

 thrives. 



Bring also a half pint of soil from a field in which 

 clover does not grow — one in a low situation or an old 

 pasture or meadow. 



Test each with blue and red litmus paper, simply 

 covering the paper with the damp soil. 



If the soil is sour the blue litmus paper will turn red. 



Clover does not thrive in sour soils. 



Now mix a little powdered lime with the sour soil, 

 stirring it up thoroughly and then letting it stand for a 

 day or two. Then test again. What effect does lime 

 have upon a sour soil? 



