Exposure Effect on White Pine Seedlings 169 



An attempt was also made to determine the rate of loss with 

 the same kind of stock. Twenty seedlings were washed free of 

 soil and shaken until all free water seemed to have been evapor- 

 ated, and were weighed at intervals of about 10 to 15 minutes, 

 being exposed between weighings on a transplant board to a 

 slight draught in an open window; temperature being 28° C, 

 hygrometer 100 per cent. The following series resulted : 



Only twice as much evaporation had taken place after an hour 

 as during the first 13 minutes. To determine whether the roots or 

 the tops were responsible for this retardation 10 plants were cut 

 at the root collar and weighed, roots and tops separately, from 

 time to time. The following interesting results appeared. 



