34 GROWTH OF PLANTS 



in the region, on recently excavated soils, or similar phenomena on recently- 

 plowed meadows or pastures of long standing. Peter " studied the seed 

 content of soils of the forest that had been planted on meadow, swamps, or 

 pastures for known periods and kept free from open land plants by deep 

 shading. In general, as the age of the forests increased, seeds of field plants 

 became more scarce and those of forest plants more abundant in the soils 

 of the forest. He found seeds of the following in deeper layers of soils of 

 forests 100 years old: Hypericum humifusum, Stellaria media, and Juncus 

 hujonius. In soils of forests 20 to 46 years old, he found seeds of a large 

 number of open-land plants belonging to various genera, such as Thlaspi, 

 Plantago, Sinapis, Juncus, Stellaria, Stachys, Anagallis, Polygonum, Cheno- 

 podium, etc. Peter concludes that seeds of some meadow and swamp plants 

 may lie in the soil more than fifty years, still capable of germination. 



Ewart 27. p. 182-183 has the following to say about the reliability of Peter's 

 conclusions: "Peter's observations are good evidence of the readiness of 

 dispersal of certain seeds, but as evidence of their longevity are quite un- 

 trustworthy. They contain a grain of truth buried in a mass of inaccuracy. 

 The same applies to all similar records of supposed old seed in soil or under 

 water being germinable, from the classical case of Mummy Wheat down- 

 wards. Here and there long-lived seed has accidentally been hit upon, but 

 in the great majority of cases the records are incorrect." Later accurate 

 records of Beal and the United States Department of Agriculture on the life 

 span of seeds buried in the soil lead one to conclude that the claims of Peter, 

 and others mentioned above, may be true in the main and that Ewart's 

 criticism of their claims is far too severe. Ewart was especially concerned 

 because the seeds that Peter claimed had long life in the soil were mainly 

 small. The buried seed results, as we shall see later, show that very small 

 seeds as well as larger seeds may live for long periods in the soil. 



There is little doubt of Ohga's "^ claim of great age of the Nelumbo nucifera 

 seeds he excavated from a naturally drained lake bed in Manchuria. The 

 seeds were buried about 1.5 meters deep in a layer of gray mud covered in 

 turn by a layer of peat and a layer of loess. The eroding river which drained 

 the lake has now cut a channel through the lake bed about 13 meters deep. 

 Since there were no Nelumbo plants growing in the region, and the seeds were 

 buried so deep, Ohga concludes that the seeds were from plants growing in 

 the lake before it was drained. Judging from the rate at which the river is 

 eroding its bed, the age of the trees growing on the land since drainage of 

 the lake, and the record of a family that has been farming the drained lake 

 bed for several generations, Ohga concludes that the seeds have been 

 buried for at least 120 years and more likely for 200 to 400 years. They still 

 give perfect germination after treatment of coats. 



United States Department of Agriculture buried seed project. The most 

 extensive buried seed project on which considerable data have already 

 accumulated is that of the Seed Testing Laboratory " of the United States 

 Department of Agriculture, designated hereafter as U.S.D.A. These seeds 



