148 Dr. F. Darwin and Miss D. F. M. Pertz. [June 15, 



2pm 4 6 8 10 12 2am 4 6 8 10 



Fig. 6. — Experiment 67. Diurnal behaviour of the stoma ta of Nicotiana. 

 Experiment 68 ; August 9, 1910. — Laurel (P. laurocerasus). Conditions as in 



Experiment 67. 





vTR. 







P.M. 





A.M. 







3.7 



39 -8 



12.12 





10 -7 



55 



45 -6 



2.6 





11-4 



4.56 



42-6 



3.37 





10-9 



5.11 



38 -4 



4.49 





14 -4 



6.22 



30 -9 



6.3 





28 -6 



46 



28 -3 



7.42 





43-4 



7.45 



18 -1 



9.5 





44-7 



8.7 



9 1 









57 



4-7 



Note.—T a 





9.17 



3 -8 



Expe 



riment 67. 



10.32 



5-8 







2pm 4 6 8 10 12 2am 4 6 8 10 



Fig. 7. — Experiment 68. Diurnal behaviour of the stomata oi-P. Imirocerasus. 



