What are "Stratified" Ginseng Seeds?

In your catalogue ginseng seeds are listed as "stratified". Could you define what that means?

Stratification is a method of storing seed until their dormancy mechanism has worn off. In a wooden box, thin layers of seed are alternated with fine sifted damp layers of sand and stored for a time period specific to the species in a cool place at a temperature -again- specific for the species. Since the box contains alternating layers(=strata) of seeds and sand, the process is called stratification.
We don't have any American or Asiatic ginseng seed until the fall at which time we rush them to all our customers who have ordered them during the year. They must be plantied as soon as they arrive. Stratified seeds are already beginning the process of germination and cannot be allowed to dry out. They are packaged and shipped moist and can easily rot if not removed from the package immediately and planted.