RESISTANCE BY LEAVES TO WATER LOSS 



21 



TABLE 4 



Index of Transpirino Power, Datura 



HOUR 



UPPER LEAF SURFACE 



LOWER LEAF SUB 



FACE 



ecedlng 

 )ur 



ENTIRE LEAF 

 SURFACE FOR 

 PRECEDING 

 HOUR 



At 6iid of 

 hour 



For preceding 

 hour 



At end of 

 hour 



For pr 

 he 



Actual 



Relative 



to 

 hour 22 



Actual 



Relative 



to 

 hour 24 



Actual 



Relative 



to 

 hour 24 



(September 2) 



















11 



0.298 







0.219 











12 



0.284 



0.291 



11.2 



0.460 



0.340 



21.9 



0.315 



14.8 



13 



0.287 



0.286 



11.0 



0.429 



0.445 



28.7 



0.365 



17.1 



14 



0.252 



0.270 



10.4 



0.440 



0.435 



28.0 



0.352 



16.5 



15 



0.338 



0,295 



11.4 



0.466 



0.453 



29.2 



0.374 



17.6 



16 



0.233 



0.286 



11.0 



0.415 



0.441 



28.4 



0.363 



17.0 



17 



0.186 



0.210 



8.1 



0.295 



0.355 



22.9 



0.282 



13.2 



18 



0.097 



0.142 



5.4 



0.140 



0.218 



14.0 



0.180 



8.4 



19 



0.050 



0.074 



2.8 



0.065 



0.103 



6.6 



0.088 



4.1 



20 



0.026 



0.038 



1..5 



0.022 



0.044 



2.8 



0 041 



1.9 



21 



0.026 



0.026 



1.0 



0.031 



0.027 



1.7 



0.026 



1.2 



22 



0.026 





T n 



i. . \j 



0.021 





1 7 





1 9 



23 



0.027 



0.027 



1.0 



0.017 



0.019 



1.2 



0.023 



1.1 



24 



0.027 



0.027 



1.0 



0.014 



0.016 



1.0 



0.021 



1.0 



(September 3) 



















1 



0.030 



0.029 



1.1 



0.017 



0.016 



1.0 



0.022 



1.0 



2 





0.030 



1.1 



U . Ui / 



0.017 



1.1 



0.023 



1.1 



3 



0.033 



0.031 



1.2 



0.024 



0.021 



1.3 



0.026 



1.2 



4 



0.038 



0.036 



1.4 



0.040 



0.032 



2.1 



0.034 



1.6 



5 



0.102 



0.070 



2.7 



0.124 



0.085 



5.5 



0.078 



3.6 



6 



0.118 



0.110 



4.7 



0.145 



0.135 



8.7 



0.122 



5.7 



7 



0.143 



0.131 



5.6 



0.178 



0.162 



10.4 



0.146 



6.9 



8 



0.143 



0.143 



6.0 



0.159 



0.169 



10.9 



0.156 



7.3 



9 



0.152 



0.147 



6.0 



0.171 



0.165 



10.7 



0.156 



7.3 



10 



0.200 



0.176 



7.1 



0.212 



0.192 



12.4 



0.1841 



8.6 



11 



0.222 



0.211 



7.5 



0.353 



0.283 



18.2 



0.247 



11.6 



12 



0.243 



0.253 



10.3 



0.413 



0.383, 



18.3 



0.268 



12.5 



13 



0.293 



0.268 



10.3 



0.394 



0.404 



26.0 



0.336 



15.8 



14 



0.240 



0.267 



10.2 



0.369 



0.382 



24.6 



0.324 



15.2 



spiring power indicated by our indices is very much greater for 

 the lower than for the upper leaf surface; for the former the 

 range is from 0.014 (24 hours) to 0.466 (15 hours), or from unity 

 to 33.1; for the latter surface it is from 0.026 (24 to 22 hours) to 

 0.298 (11 hours), or from unity to 11.5. It is again apparent 

 that the minimum index for the lower surface (0.014) is much 



