LIFE SPAN OF SEEDS 



37 



extend over a period of 100 years. So many seeds were still alive at the 

 40-year period that it was decided to test the other 12 samples at 10-year 

 periods, thus extending the experiment over a total period of 160 years. 



Table 3 gives the results of the tests for periods up to the sixtieth year. 

 The plus signs in the table show the kinds of seeds that still germinated ^^ 

 at the various periods. The seeds still germinating after 40, 50, and 

 60 years' burial along with the percentage for each and the percentage of 

 all those buried that still germinated are given in Tables 4, 5, and 6, 

 respectively. 



Table 4. Seeds Alive after 40 Years' Burial 



Percentage of all seeds buried still germinating: 8.2%. 



Table 5. Seeds Alive after 50 Years' Burial 



Percentage of all seeds buried still germinating: 8.2%. 



Table 6. Seeds Alive after 60 Years' Burial 



Percentage of all seeds buried still germinating: 4.8%. 



