69, 



SO thp.t v/hen a limited amount of v/ater is present it would 

 a,t once "be absorbed by this hairy surface.Dried curled leaves 

 were placed in a moist chamber in order to determine the 

 water absorbing power of each surface of of the leaf. When 

 those unsealed leaves which had been kept in the desiccator 

 and which were completely curled after drying, v/ere later 

 placed in the moist chamber, they gained 44,53^ of their weigh-t 

 during the first tv/enty four hours and became fully expanded. 

 During the second day the gain was 4.84^, on the third 4,53^, 

 on the fifth 6,15% and during the sixth and seventh days the 

 leaves showed no more gain in weight. The average total percent 

 of gain for the v:hole week amounted to 60.10^,Those leaves 

 whose upper surfaces only were sealed gained during the first 

 day 16.29^,on the second 3.45^,on the third 7.8^,during the 

 fourth 1,32'^, during the fifth 0,63^ and during the sixth 

 and seventh days together the gain observed was only 0,62% 

 making a tota3]of 30. 61^. At the end of the fifth day these 

 leaves began to mnfolc. r.nd by the end of the sixth day they 

 were fully expanded, The leaves whose lower surfaces were 

 sealed showed a gain of only 1.25^ during the first day, of 

 1.64^ during the second day, of, 52^ during the fourth, and of 

 0.01^ during the fifth and sixth days together thus making 

 for the whole week a total gain of only 3.42^.Thi£ gain in 

 weight was accompanied by no appreciable difference in the i 

 physical appearance of the leaf. Whether any part of the observed 

 gain in these three experiments was due to the actual 

 condensation by the leaf itself of the water vapor present 



