100 
WM. CROCKER 
stituting it one of the bad weeds of Minnesota, the Dakotas and 
western Canada; while the latter grows rather readily in the late 
summer and fall and is killed by the severe freezing of winter. When 
in the eighties the Germans^ began introducing the wild legumes as 
forage crops they found one of the great drawbacks was the persistent 
dormancy of the seeds. Seeds of many plants have a dormancy that 
persists only until the spring following ripening. Others are carried 
over two or more winters in the quiescent condition, while still others 
have the germination of a single crop distributed over the growing 
seasons of from one to many years. 
The maximum time that seeds can lie in the ground in a dormant 
but viable condition is a matter of much interest and one that has 
received considerable attention. Numerous observations'* of the 
vegetation appearing upon soil freshly turned up by the digging of 
wells, ditches, the removal of buildings and the plowing of old meadows 
and pastures, indicates that various seeds may lie in the soil quiescent 
and viable for 25 or even 50 years. Peter took samples of soils at 
various depths from forests that had been grown upon meadow 
and farm lands for known periods ranging from 20 to 150 years and 
subjected these soil samples to germinative conditions. The samples 
from younger forests showed seeds of farm weeds and meadow plants 
prevalent, while in the older forests there was a gradual displacement 
by seeds of forest vegetation, and in the oldest forests only the latter 
appeared. The soil from forests 20 to 46 years old produced 41 species 
of farm weeds and 35 of meadow plants. In forests over 100 years 
old he still found Hypericum humifusum, Stellaria media and J uncus 
hufonius. From his work Peter concludes that seeds of certain plants 
may lie quiescent in the soil for more than 50 years still capable of 
germination when supplied proper temperature, light and moisture 
conditions. Perhaps Ewart has been over severe in his criticism of 
this rather careful work notwithstanding the possible errors neces- 
sarily involved in the method. However this may be, later and con- 
clusive experiments upon buried seeds tend to confirm Peter's con- 
clusions. 
Beal^ has found that out of 22 species representing 16 families, 
including common plants, mostly weeds, 11 species did not retain 
3 Michalowski, Wiirt. Wochenbl. Landwirtsch. 13: 175. 1894. 
* Peter. Nachr. Konigl. Ges. Wiss. 673. 1893; 373. 1894. 
' Beal, Vitality of Seeds Buried in the Soil. Amherst, Mass. 
