EBPEODUCTIVE ORGANS OP PLANTS. 305 



growing plant, shriveling and shrinking greatly in bulk, 

 and finally falling away and passing into decay. 



VITALITY OF SEEDS AND THEIR INFLUENCE ON THE 

 PLANTS THEY PRODUCE. 



Duration of Vitality. — ^In the mature seed when kept 

 from excess of moisture, the embryo lies dormant. The 

 duration of its vitality is very various. The seeds of the 

 willow, it is asserted, will not grow after having once be- 

 come dry, but must be sown when fresh ; they lose their 

 germinative power in two weeks after ripening. 



With regard to the duration of the vitality of the 

 seeds of agricultural plants there is no little conflict of 

 opinion among those who have experimented with them. 



The leguminous seeds appear to remain capable of 

 germination during long periods. Girardin sprouted beans 

 that were over a century old. It is said that Grimstone 

 with great pains raised peas from a seed taken from a 

 sealed vase found in the sarcophagus of an Egyptian mum- 

 my, presented to the British Museum by Sir G. Wilkinson, 

 and estimated to be near 3,000 years old. 



The seeds of wheat usually lose their power of growth 

 after having been kept 3-7 years. Count Sternberg and 

 others are said to have succeeded in germinating wheat 

 taken from an Egyptian mummy, but only after soaking 

 it in oil. Sternberg relates that this ancient wheat mani- 

 fested no vitality when placed in the soil under ordinary 

 circumstances, nor even when submitted to the action of 

 acids or other substances which gardeners sometimes em- 

 ploy to promote sprouting. Vilmorin, from his own trials, 

 doubts altogether the authenticity of the " mummy wheat." 



Dietrich, {Hoff. Jahr., 1862-3, p. 77,) experimented 

 with seeds of wheat, rye, and a species of Bromus, which 

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