356 CO. ROSENDAHL 



was made to transplant into the same kind of soil as the plants 

 were found in, and rich sandy loam was used for practically all. 



Most of the plants as soon as they had been potted and put 

 into flats were divided into two sets, one of which was put into 

 the forcing house at once, the other was left outside to freeze. 

 This work was completed about the middle of October. A few 

 of the plants left outside, were given only a slight freezing — 28°F. 

 for about four days^ — and then transferred to the forcing house. 

 The remainder were kept outside until December 16 to 18, and 

 thoroughly frozen. They were then all taken in and left in the 

 potting room to thaw out for two days. After this they were 

 transferred to the forcing house and placed alongside the others, 

 so that throughout the forcing period they were all under the 

 same light, temperature, and moisture conditions. 



The following observations and data are copied from the notes 

 kept, and for convenience will be set down in tabular form. It 

 should be stated that there was no intention at the outset of 

 gathering these data for publication and that the notes were taken 

 only in a fragmentary manner. Only such facts as might prove 

 of interest and value in individual cases were recorded and 

 hence no uniformity or consecutiveness runs through the notes. 

 They are given here in the brief disconnected manner in which 

 they were recorded. 



The temperature of the forcing house throughout most of the 

 period ranged from 60° to 65°F. during the day, while the night 

 temperature averaged 15° less or 45° to 50°. Towards the end 

 of the period — March 15 to April 15, the day temperature rose 

 considerably higher than 65°. 



In those cases where the plants were put into the greenhouse 

 without any previous freezing, results were almost wholly nega- 

 tive as far as flowering was concerned. The plants made con- 

 siderable growth although uniformly slower than in the cases 

 where they were thoroughly frozen. Only occasionally were 

 flowers produced and then only in limited numbers and sometimes 

 intermittently. It would seem from this, together with the 

 results shown in table II, that the stimulus of thorough freezing 



