330 GEORGE HARRISON SHULL 



of a century of rest. This capacity to rest during considerable 

 periods of time prevents the extinction of a form under severe 

 competition, or temporarily unfavorable conditions, allowing 

 the organism to take advantage of any event which reduces or 

 removes the competition or restores conditions favorable to 

 growth, and in many cases it is also an important condition for 

 successful introduction into new areas. 



Darwin recognized the importance of the durability of seeds 

 in water as a condition favorable to the stocking of the islands 

 of the sea, and experimentally determined that some seeds could 

 withstand the action of artificial sea water for 137 days, and if 

 they should possess at the same time the ability to float, they 

 might be carried over long stretches of ocean and lodged under 

 favorable conditions for development on some distant strand. 

 Other European investigators performed similar experiments 

 and are said to have extended the time of submergence to 13 

 months. 



In the spring of 1904 an event occurred which raised in a 

 striking manner the question as to the length of time during 

 which a seed might remain submerged and still germinate. 

 Nachaquatuck Creek, whose submerged lower course forms 

 Cold Spring Harbor on the north shore of Long Island, was 

 dammed in three places about the fourth decade of last century, 

 in order to supply water-power for the turning of two woolen- 

 mills and a flour-mill, all of which have been long since abandoned, 

 the mills having either disappeared or fallen into decay. The 

 mill-ponds remain as delightful features, biologically and sceni- 

 cally, of Cold Spring Harbor. The lowest and largest of the 

 three ponds, known as St. John's pond, has a length of about 

 400 meters, a maximum width of 265 meters and includes an area 

 of approximately 8 Ha. (about 20 acres). 



end of the row of bottles, which were buried about twenty inches below the sur- 

 face of the ground. I should make an exception in the case of the acorns, which 

 were placed in the soil near the bottles and not inside the bottles. At the end of 

 five, ten, fifteen, twenty, twenty-five and now thirty years, sets of these seeds 

 were tested for vitality." 



After thirty years burial, seeds of the following species germinated: Amaran- 

 thus retroflexus, Brassica nigra, Capsella bursa-pastoris, Lepidium Virginicum, _ 

 Oenothera biennis, Rutnex crispus, Setaria glauca, Stellaria media. 



