— 149 — 



pr, 100 cm 2 (absolute transpiration) (Tb. 1) and 2. the relative 

 transpiration, viz. the transpiration in proportion to the evaporation 

 from a water surface of 100 cm 2 (The rate of evaporation = 100) 

 (Tb. 2). 



Table 1. Transpiration pr. 100 cm 2 leaf area pr. hour in g. 



(100 cm 2 = 50 cm 2 of the upper surf, -f 50 cm 2 of the lower surf.). 



1914 



U U 



28/ 

 /6 



7 7 



23 / 8 



30/ 

 IB 



7a 



Mean 





Moisture, % . . 



42 



52 



71 



64 



, 86 



67 









Temperature . . 



22.8 



15.5 



22.2 



19.0 



i9.6 



17.7 









Evaporation . 



4.52 



2.40 



1.81 



3.08 



0.78 



4.12 









Empetrum .... 



0.28 



0.23 



0.27 



0.41 





0.39 



0.32 







Vacc. Vit. idaea 



0.48 



0.28 



0.22 



0.37 



0.13 



0.63 



0.35 







Vacc. uligin. . . 



0.52 



0.34 



0.31 



0.62 



0.12 



0.72 



0.44 







Betula 



0.26 



0.27 



0.26 



0.47 



0.19 



0.50 



0.33 







1915 



/6 



13 / 6 



20/ 



n /i 



25 / 7 



15/ 



29 / 8 



12/ 

 19 



Mean 



Moisture, °/ 0 . . 



! 58 



44 



62 



79 



84 



73 



81 



67 





Temperature . . 



14.8 



14.4 



12.2 



16.4 



18.3 



18.5 



12.9 



16.7 





Evaporation . . 



4.25 



5.63 



1.48 



2.44 



0.99 



3.33 



0.74 



4.20 





Empetrum 



0.28 



0.32 



0.19 





0.19 



0.43 





0.25 



0.28 



Vacc. Vit. idaea 



0.28 



0.29 



0.20 



0.34 



0.16 



0.48 



0.13 



0.48 



0.30 



Vacc. uligin. . . 



0.31 



0.37 



0.24 



0.34 



0.18 



0.48 



0.09 



0.64 



0.33 





0.33 



0.30 



0.29 



0.44 



0.21 



0.48 



0.11 



0.44 



0.33 



Table 2. Relative transpiration. 



(Transpiration from 100 cm 2 leaf area in proportion to the 

 evaporation from a water surface of 100 cm 2 . The rate of 

 evaporation = 100.) 



1914 





2 7e 



% 



2 7 8 



30/ 



/a 



7» 



Mean 



Empetrum 



6 



10 



15 



13 





9 



11 



Vacc. Vit. idaea 



11 



12 



12 



12 



17 



15 



13 



Vacc. uligin. . . 



12 



14 



17 



20 



15 



17 



16 



Betula 



6 



11 



14 



15 



24 



12 



14 



