The Water Relations of the Pine and the Silver Tree. 13 
These results are shown in graphical form in the figure on page 17. 
In connection with Experiment No. 33 it is to be noted that at the end 
of the experiment the Leucadendron leaves were very dried up, while the 
Pine needles still appeared fairly fresh. In fact the Leucadendron leaves 
were quite shrivelled up several days before the Pine needles began to die 
and turn brown. 
One or two determinations were made of the water content of fresh 
leaves, in the hope that this would throw some light on the results of the 
transpiration experiments. In Experiment No. 3 two twigs, one of Leuca- 
dendron and one of Pine, were kept in water overnight, and left on the 
roof of the laboratory with their cut ends in water for about an hour and a 
half the following morning. At the end of this period the fresh weight of 
the leaves was determined, and also their area ; they were then dried and 
the dry weight determined. In Experiments Nos. 22 and 24, two twigs were 
kept overnight in water, and a few leaves were picked from each the 
following morning. The fresh weight, area, and dry weight of each set were 
then determined. The result of these experiments was to show that the 
Pine leaves have a larger water content per square metre of leaf surface 
than the Leucadendron leaves, but a lower water content per cent, of fresh 
weight. 
Experiment No. 3. 
No 3 : Leucadendron. 
No. 3 : Pine. 
Leaf area ...... 
Fresh weight of leaves 
Dry „ „ . 
Water content ..... 
Water content per square metre leaf 
surface ...... 
Water content per cent, fresh weight 
1742 8 square cm. 
33 82 grm. 
1420 „ 
19-62 „ 
112-6 „ 
58 02 per cent. 
1090 square cm. 
36 45 grm. 
18 35 „ 
181 
1661 
49 66 per cent. 
Experiments Nos. 22 and 24. 
No. 22: Leucadendron. 
No. 24: Pine. 
Leaf area ...... 
Fresh weight of leaves 
Dry „ „ ... 
Water content 
Water content per square metre leaf 
surface ...... 
Water content per cent, fresh weight . 
173-48 square cm. 
2-995 grm. 
1-08 „ 
1-915 „ 
110-4 
63 93 per cent. 
115 2 square cm. 
3 145 grm. 
]-326 ., 
1819 „ 
1579 
57'84 per cent. 
A number of experiments were also performed with twigs of Leuca- 
