PLATE 29 



A plant of bunchberry, Cornus canadensis, the seeds of which do not germinate 

 without chilling. 



Bunchberry seeds sown October 9, 1912, and chilled during the winter germinated 

 promptly the following spring. Another lot of the same seeds sown on the same date 

 but kept in a greenhouse at a temperature of not less than 55° F. showed no germina- 

 tion in 12 months. These seeds were then chilled for 2 months at a temperature of 

 35 to 40 F., and when brought back into the greenhouse they germinated within 

 a month. The very healthy plant shown in the illustration grew from one of these 

 long-dormant seeds. The exposure of seeds to winter weather is sometimes practiced 

 by gardeners, but they usually attribute its beneficial effect to freezing, which in all 

 the cases tried in these experiments is unnecessary. 



