Dormancy and Germination of Seeds 269 



few legumes have germinated after storage for 80 years. Experi- 

 ments have shown that the seeds of a number of our common 

 weeds will withstand burial deep in the soil for more than 30 

 years. The seeds of water plants will remain alive under aerated 

 water for the same length of time. The seeds of several land 

 plants have remained alive under water for periods of from 4 to 

 12 years. It is therefore safe to say that the seeds of most culti- 

 vated plants deteriorate rapidly after 2 years; that the seeds 

 of many wild plants remain alive for 5 to 10 years ; and that a 

 few may live under favorable conditions 25 to 50 years. No 

 seeds are known to have remained alive 200 years. 



Storage of seeds. One of the important conditions for the 

 storage of most seeds is that they be kept dry. When seeds are 

 stored for long periods in soil, the absence of germination seems 

 to depend on lack of sufficient oxygen. The same is probably 

 true for storage under water. Seeds like those of the soft maple 

 live longest when kept cool and moist. 



In general, seeds may be kept longer and show greater vitality 

 if they are thoroughly mature when harvested. Corn and wheat 

 seeds lose their vitahty rapidly when not mature and well dried 

 out. The seeds produced in wet seasons usually show poorer 

 germination than those produced in dry seasons. Moreover, 

 corn matures late in the autumn, and unless its water content 

 falls below 20 per cent before killing frosts come it is sure to be 

 injured. Corn that is to be used for seed the following year should 

 be gathered as soon as mature and placed in racks, so that it will 

 dry out rapidly. 



The changes that take place during storage that lead to the 

 death of the embryo have been much studied. One important 

 fact discovered is that during prolonged storage the proteins are 

 gradually coagulated or changed into insoluble forms, so that 

 when the seeds are planted the proteins do not become soluble 

 and the protoplasm dies. Seeds will not remain alive, therefore, 

 after their proteins have coagulated. Since this takes place 



