THE ASSOCIATION OF CHARACTERS 261 



reached by selecting on the ground of seeds of equal size, or 

 simply on the base of choosing the largest seeds. Apart 

 from these general correlations there are two minor points, 

 for which I might call your attention. The first is indicated 

 by the common proverb : 



One year's seed 

 Is seven years' weed. 



It means, that a large number of weeds and other wild 

 plants produce seeds, only a part of which will germinate 

 in the next spring. Another part will sleep in the soil and 

 only be awakened in the spring of the following year, whilst 

 the more resistant kernels will stand two or more years and 

 come into germination after this prolonged period of rest. 

 Some spare seeds may even rest as long as six or seven years; 

 whence the saying quoted. This rule is not at all limited 

 to weeds, but embraces the different sorts of clover and of 

 other allied leguminous forage plants. 



Now, here also, we observe a correlation between the 

 size of the seeds and the time required for their germination. 

 As a rule, the smaller seeds have the thickest and hardest 

 coats, as we have already seen, and it is exactly the extreme 

 resistance of the coats, which causes them to lie dormant 

 for so long a time. If we sow seeds of common clover or 

 of the crimson species (Trifolium incarnatum) on a layer 

 of moist blotting paper, we can easily pick out day after day 

 those which produce their rootlet. In the main the larger 

 seeds will thus be seen to germinate first, and after a week 

 or more only the small kernels remain. Among these, 

 some will germinate during the next weeks, but some spare 

 ones will remain dormant until the next year. 



Evidently it is of high practical interest, in the first place, 

 to have all or nearly all the seeds of a sowing germinating 

 in the same spring, and in the second place to have them all 

 coming up in the same week or at least as nearly at the same 



