Killing of Plant Tissue by Low Temperature 



l8: 



Table 12. Showing Percentage of Proteids in Frozen and 

 Unfrozen Sap from Tissues of Apple, Pear, Peach and Plum. 



In no case does there seem to be any conclusive indications 

 that proteids were precipitated by temperatures low enough to kill 

 the plant tissue. Since there was no precipitation from the sap of 

 tender twigs in early autumn, sap was not taken from twigs later in 

 the season. 



Cabbage and other succulent plants grown in the greenhouse, 

 some well watered, some under dry conditions and others grown out 

 of doors, also well watered but under conditions where they would 

 withstand lower temperatures than would those grown in the green- 

 house, had each an abundance of sap expressed, half of it being frozen 

 to a temperature that would kill those well watered in the greenhouse, 

 but would not kill those grown out of doors. Samples of each of 

 these frozen and unfrozen were analyzed for proteids, with the re- 

 sults shown in the following table: 



