49 2 Delf . — Transpiration and Behaviour of 
During the whole time of the experiment the plants were exposed out- 
side the laboratory in a position sheltered from wind and from the morning 
sun ; direct sunlight fell upon the plants only after 12 p.m., and until about 
4.30 p.m. It will be seen that the weighings of the crimson Salicornia and 
Suaeda were begun later in the day than those of the other two plants ; and 
accordingly both these plants show a higher initial transpiration value than 
the ‘ apple green ’ Salicornia. The maximum rate of transpiration per hour 
per 100 sq. cm. was attained by Suaeda. If the water content per 100 sq. cm. 
be taken as a rough measure of the degree of succulence of the plant, it will 
be seen (see Table VI) that Suaeda was also the most succulent of the 
plants examined, and it thus appears at once that the succulent habit is not 
necessarily due to or even coincident with a reduced rate of transpiration. 
TABLE VI 
Degree of Succidence of Mercurialise Salicornia , and Suaeda. 
Fresh Weight 
Dry W eight at ico° C. . . . 
Water Content per cent. . . 
Surface Area 
Water Content per 100 sq. cm. 
Merairialis. Apple Green Sal. 
0*560 grm. i*8ii grm. 
0*129 grm. 0*190 grm. 
76 - 97 % 89 - 5 % 
45.14 sq. cm. 24.43 sq. cm. 
0.95 grm. 6*5 grm. 
Crimson Sal. Suaeda. 
1-345 g rm - 2.240 grm. 
0-141 grm. 0-219 grm. 
89 - 5 % 9 °' 3 % 
17.44 sq. cm. 40*38 sq.cm. 
6*i grm. 10 grm. 
During the course of the experiment there is, except in the case of ‘ apple 
green ’ Salicornia , an initial transpiration value which quickly shows a con- 
Fig. 8. Curves showing average transpiration per hour per ioo sq. cm. in cut shoots not 
supplied with water, a = Mercurialis annua ; B = Salicornia annua (crimson red) ; c = Salicornia 
annua (apple green) ; D = Suaeda maritima . Ordinates represent loss of weight in grammes ; ab- 
scissae represent time intervals of one hour. Figures taken from Table V. 
siderable diminution. In Fig. 8 this is shown graphically ; the horizontal line 
representing the average transpiration during any given period of time. 
