490 
Delf . — Transpiration and Behaviour of 
TABLE III 
A. Diameters of Successive Internodes. 
O') 
(m) 
0.354 cm. 
0.470 cm. 
0-334 „ 
0.342 „ 
0*338 », 
0-357 » 
0-326 ,, 
o *357 „ 
0.281 „ 
o- 33 i „ 
0.268 ,, 
0.270 ,, 
0.184 ,, 
o -233 „ 
s 
0.160 „ 
0.203 ,» 
. Results. 
Fig. 6. Outline obtained by removing celluloidii 
Height of Shoot 
= 5-30 cm. 
film from shoot of Salicovnici , and stretching i 
Mean Diameter of Shoot = 0.300 
upon squared paper. 
Surface Area of Shoot 
= 4-99 sq. cm. 
Surface Area of Film 
= 5-oo 
Error =0.2% 
In a second experiment of the same kind the film was removed without 
injury to the shoot, which was therefore dipped again into the solution, so 
that a second film was obtained. The measurements are shown in Table IV, 
and the films in Fig. 7. 
TABLE IV 
A. Diameters of Successive Internodes. 
(*) (w) 
0.288 cm. 0-324 cm. 
0302 „ 0.337 » 
0*275 „ 0*297 „ 
0*237 » °* 2 74 >, 
°* I 94 » 0-233 „ 
0.162 ,, 0.162 ,, 
B. Results. 
Height of Shoot = 0.257 cm, 
Mean Diameter of Shoot = 3.35 ,, 
Surface Area of Shoot =2.70 ,, 
Surface Area of Film (1) = 2-70 ,, 
(2) = 2-72 „ 
Error = 0.7% 
Fig. 7. Outline of two films obtained suc- 
cessively from the same shoot of Salicornia. 
The most obvious source of error in working with a celluloidin film is the 
difficulty of removing the film when it is sufficiently firm not to suffer dis- 
tortion, and is yet not wrinkled or shrunken. The preliminary experiments 
with a glass rod showed that if the film is not firm, it may stretch in its 
removal by as much as 20 % of the true area ; on the other hand, in 
removing a film from such a stem as that of Salicornia , the edges of the 
part first lifted sometimes shrivel, and then a very low value for the surface 
area would be obtained. It will be seen, however, that good films success- 
fully removed gave a very fair approximation to the calculated areas in the 
case of the glass rod, and they may also show a near approximation to the 
actual surface area in the case of the shoot. On the whole, then, it appears 
