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1904] BERGEN—TRANSPIRATION OF EVERGREENS 293 
Pistacia, 1-4 per cent.; Rhamnus, 4-6 per cent. The results of the 
determinations of comparative transpiration are as follows: 
Ratros L088 oF SUN Leaves _ 
Loss or SHADE LEaves 
Olea Pistacia Q. Ilex Rhamnus 
a fare etc 
I, Sun leaves in sun and shade leaves in 
e. 
ee. 3.04 4.60 10.70 7-90 
et. 1.45 2.20 BS 2.25 
Average of all values obtained....._. 2.10 3-70 6.35 5-91 
II. Both kinds of leaves in full sunlight. 
ns. 2.25 2.24 3-99 1.43 
ta aa aa I.17 1.00 0.96 0.52 
Average of all values obtained....___ 1.47 L.70 2.04 0.98 
III. Both kinds of leaves in the shade. 
ee 97 2.58 2.70 2.61 
ao... 0.81 0.68 0.93 tea 
Average of all values obtained....... 0.90 1.87 1.86 1,86 
Summing up the results of the experiments on comparative trans- 
piration (taking into account some aberrant values not included in 
the table above given), the following conclusions may be stated: 
1. Under the conditions normal for each class (I), sun leaves 
transpire from three to ten times as much as the shade leaves of the 
Same species, 
2. With both 
classes of leaves under abnormally equal conditions 
Ul and IIT) the sun leaves of the species studied usually transpire 
more than one and one-half times as much as the shade leaves.® 
a averaging the averages of II and III, it appears that the 
Bi a of transpiration of sun leaves and shade leaves is about 
“manifest in sunshine as in the shade. 
abe = thinnest and most poorly nourished shade leaves con- 
a... more sharply with sun leaves in their behavior than do 
is th ty normal leaves which have developed in the shade. This — 
eer De! cause for the difference between maximum and 
Q. Pay results, particularly noticeable in the transpiration of 
_ babies is quite at Variance with what would probably be the a priori opinion 
Pflanzen, agian Seg directly contravenes the statement of WIESNER (Biologie der 
