332 



EDITH BELLAMY SHREVE 



Experiment 9. 



Object: (1) An investigation of the changes in turgidity between day and 

 night, as measured by the difference between water-intake at the roots and water- 

 loss by transpiration for the same period. (2) A comparison of the changes in 

 turgidity with the movements of the joints. 



TABLE 7 



Experiment 9. Correlation of movements of Opuntia and water-content of the 



tissues 



WATER-CONTENT 



Gain Loss 



Up 



Down 



E* 



Plant No. 13 



June 28, 6 p.m. 

 June 29, 6 a.m. 

 June 29, 6 p.m. 

 June 30, 6 a.m. 

 June 30, 6 p.m. 



□ 



Plant No. 14 



June 28, 6 p.m. 

 June 29, 6 a.m. 

 June 29, 6 p.m. 

 June 30, 6 a.m. 

 June 30, 6 p.m. 

 July 1, 6 a.m.. . 

 July 5, 7 p.m.. 

 July 6, 7 a.m.. . 

 July 6, 6 p.m.. 

 July 7, 7 a.m.. . 

 July 7, 6 p.m.. 

 July 11,6 a.m. 



□ 

 ■ 



■ 

 □ 

 ■ 

 □ 



* T = total transpiration for the period indicated. 

 A = total absorption for the period indicated.. 

 E = water loss per hour from standard atmometer. 



Material: Plants Nos. 13 and 14. No. 13 had been growing in the open until 

 a month before the time of the experiment, when it was cut off just above the 

 roots and placed with its lower end in a bottle of water. As soon as a large fibrous 

 root system had developed in the water the plant was considered ready for use. 

 No. 14 was a two year old individual which had been raised from seed in the 

 green-house. It was removed from the bed with a large fleshy root intact and 

 placed with its roots in a second bottle of water. Many of the small roots were 



