Adaptation to Environment. 



311 



Expedition, relates the following remarkable instance of 

 resistance to cold by Cochlearia fencstrata, a member of 

 the mustard family, shown in its natural size by Fig. 162. 

 The cold was very 

 persistent, and of- 

 ten fell lower than 

 46° below zero, Cen- 

 tigrade. The plant 

 in question grew 

 upon the summit of 

 a rather high sand 

 hill near Pitlekai, 



exposed to the continuous and sharp 

 north and northeast winds. It began 

 to bloom in the summer of 1878, but 

 its full quota of flowers was far from 

 complete when winter arrived and 

 stopped its further development, 

 the inflorescence then consisting 

 of flower buds in different stages 

 of development, newly opened 

 flowers, faded flowers, and more 

 or less ripened fruit. There 

 were only a few shriveled re- 

 mains of the basal rosette of 

 leaves, but the upper leaves 

 were alive and fresh. In this 

 condition the plant was over- 

 taken by winter and exposed to its full severity. One 

 might expect it to be destroyed under such circumstances, 

 but this was not the case; for when the summer of 1879 

 began, the plant resumed its development where it left ofE 

 at the beginning of winter : the flower buds unfolded and 



Fig. i6z. 



Cochlearia fenesfrata, natural size. 

 After KjELLMAN. 



