Killing of Plant Tissue by Low Temperature 



197 



Material 



Rose Geranium, wet 



and turgid 



Rose Geranium, wilted. 

 Common Geranium, 



turgid 



Common Geranium, 



wet and turgid 



Common Geranium, 



wilted 



Common Geranium, 



turgid 



Common Geranium, 



wet and turgid 



Common Geranium, 



wilted 



Morning-glory, turgid. . 

 Morning-glory, wet 



and turgid 



Morning-glory, wilted.. 

 Morning-glory, turgid.. 

 Morning-glory, wet 



and turgid 



Morning-glory, wilted. . 



Coleus, turgid 



Coleus, wet and turgid 



Coleus, wilted 



Fern, turgid 



Fern, wet and turgid.. . 



Fern, wilted 



Fern, turgid 



Fern, wet and turgid.. . 



Fern, wilted 



Fern, turgid 



Fern, wet and turgid... 



Fern, wilted 



Mulberry, turgid 



Mulberry, wet and 



turgid 



Mulberry, wilted 



Date 



uly 



uly 



24 



24 



uly 24 



uly 24 



uly 24 



uly 31 



uly 31 



uly 31 

 uly 31 



uly 31 



uly 31 



Aug. 3 



Aug. 



Aug. 



Sept. 



Sept. 



Sept. 



Sept. 



Sept. 



Sept. 



Sept. 



Sept. 



Sept. 



Sept. 



Sept. 



Sept. 



Sept. 



Sept. 

 Sept. 



'12 



'12 



'12 

 '12 

 '12 



'12 

 '12 



'12 

 '12 



'12 

 '12 

 '12 



'12 

 '12 

 '12 

 '12 

 '12 

 '12 

 '12 

 '12 

 '12 

 '12 

 '12 

 '12 

 12 

 '12 

 '12 



9,'12 

 9,'12 



Tem- 

 pera- 

 ture 



-3 

 -3 



-3 



-3 



-3 



-2 



-2 



-2 

 -2 



-2 

 -2 

 -2 



-2 



-2 



-2.5 



-2.5 



-2.5 



-2 



-2 



-2 



-2 



-2 



-2 



-2 



-2 



-2 



-2 



-2 

 -2 



Num- 

 ber of 

 Leaves 



Percent- 

 age all 

 Killed 



4 



4 



4 

 4 

 4 



4 



4 

 3 



3 

 3 

 4 



4 

 4 

 4 

 4 

 4 

 5 

 5 

 5 

 5 

 5 

 5 

 5 

 5 

 5 

 5 



5 

 5 



Percent-I 



age 1 



Total I 



Surface 



Killed I 



Per- 

 cent- 

 age 

 Weight 

 Lost 



Average percentage surface killed, leaves of succulent 

 plants, turgid , 



Average percentage surface killed, leaves of succulent 

 plants, wilted 



100.0 

 100.0 



95.0 



90.0 



100.0 



100.0 



80.0 



100.0 

 100.0 



100.0 



0.0 



15.0 



100.0 



15.0 



25.0 



50.0 



100.0 



0.0 



15.0 



60.0 



5.0 



7.0 



20.0 



40.0 



55.0 



40.0 



5.0 



0.0 

 0.0 



50.3 

 51.4 



On January 22, 1913, apple roots from one-year-old seedling 

 stock were frozen to -9 C in 3}/^ hours: 

 (a) Two kept in water 18 hours. 



All were injured. The crown cuts slightly in cambium; 



and the second and third in cainltiuni and cortex severely. 



