Water in Trees under Australian Conditions. 
89 
Loss per hour per sq. metre, 3-9 grams. 
Loss per hour per stoma, *00005 milligram. 
Rate of ascent, 25*5 cm. per hour. 
Amount passed through similar branch under its own head = 0*4 gram 
per hour. Hence head of water required to produce transpiratory rate 
of flow would be at least forty times length of stem. 
The observations on rooted plants in pots were prolonged throughout 
the year, but only those data are given which represent various conditions 
at the different seasons. The appended curves give the relation between 
the temperature and the amount of evaporation from the plant and from 
a free surface of water. The hot wind is also a very dry one. Hence the 
enormous rise in the rate of evaporation, whereas the hot north wind about 
27 0 C. causes the transpiration to undergo a regulatory decrease. 
B. Trees in Pot. 
Eucalyptus corynocalyx (young tree with oval dorsiventral leaves, 
stomata on under surface only), area of transpiring surface, 5> I2 ° sq. cm * 
Winter. 
Date and 
Conditions. 
Loss per hour 
Loss per hour per sq. 
Temperature. 
18. 6. ’08 
per sq. in. 
free surface of wc 
16*5° 
1 v 7. ’08 
N. wind, dry 
Loss per 
33-2 grams 
stoma = *oooi6 milligram 
293 grams 
13 ° 
14. 10. ’oS 
Clear sky, no wind 22-2 grams 
Loss per stoma = .00011 milligram 
Summer. 
268 grams 
27 - 5 ° 
Clear, sun, slight 
N. wind 
395.8 grams 
707 grams 
26. 10. ’08 
Loss per hour per stoma = 00198 milligram 
2 4 0 
Clear, sun, slight 
S. wind 
97.9 grams 
597.8 grams 
28. 10. ’08 
Loss per 
hour per stoma = *000489 milligram 
22 * 5 ° 
2. II. ’oS 
Dull, no wind, little 
sun 
97*9 grams 
219*5 grams 
2 7 ° 
5. 11. ’08 
Hot sun, little wind, 
atmosphere moist 
325 grams 
536*6 grams 
21° 
23. II. ’08 
Dull, slight wind 
118 grams 
243.9 grams 
27 ° 
25. I I. ’08 
Hot sun, no wind, 
air moist 
195 grams 
439 grams 
33 ° 
30. IT. ’08 
Hot sun, no wind, 
atmosphere dry 
263*5 grams 
975.6 grams 
36 ° 
Hot sun, no wind, 
atmosphere dry 
295*8 grams 
1,805 grams 
