21 
from the mass of bases. A stout stake was driven into the ground until 
its top was exactly even with the tip of this leaf. All measurements given 
are from the top of this stake and are expressed in millimeters. Incre- 
ments since the preceding measurements are indicated by boldface type. 
The heights of the stakes were, respectively, 500 and 1,320 millimeters. 
The experiments began on February 8: 
Date | Leaf A. Leaf C | 
=n es ek, 
Feb. 10° MS Giges neck oie SO ees 
Feb. 17 | 2.5 1.5 190 150 
Feb, 22 3 oO 306 116 
Feb. 24 (16) fIB) Toss Siieoriee, rete 
Mar. 1 88 85 404 98 
Mar. 10 311 2238 550 146 
Mar. 17> 494 183 665 115 
Mar. 23¢ 659 165 772 107 
Mar. 30 784 125 885 113 
Apr. 64) 895 111 1, 004 119 
U 
«Plant watered. ¢ Watered last, March 20. 
> Leaf begins to expand. 4Marked part of both leaves expanded. 
The following contains a more detailed tabulation of the growth of 
these two leaves for a portion of the time included in the preceding one 
and shows the relative growth by day and by night. All measurements 
given are the increments during the preceding periods: 
| Leaf A. Leaf C. 
Date. Hour. se Aa eA Tasca 
Day. | Night. | Day. Night. 
POD, 22" °6:8;, 10, [ese eee | eS WL coe br 
9:8. coccc oe fa ee | ee ae 
| 2) re | be etiam, pea A oC! | _ (eee a 
Feb. 23 | 6a. m. |--.-.____ eee: ‘tole 5 
Ss 1s a eee | a eee | (1) aera 
| p.m. |. [Lae 1 Pe ne | 
Keb; 24-|-6:a. mi }L 2 ) | ee Se ts were. 11.5 | 
i og a alee es cay | a IA fl es een | 
Feb. 25 | 6 a.m. fea? scl el eee 15.5 
Mar. 10)) 6: a.m (2220252 J|o 0 oe eee Jonas soe 
6p. m. ose UWrtssesccsce 
Mar: 21 6ia. cine ps es ws a Sees | 1b - 
6p. m. bay Inge gia ee | Ohi pose | 
Mar, 12) 6a, cS ys Bl ee: | 18 | 
| 9p. m. (a eer 3 | ase | 
Mar. 13 | 6a. m, |__-_-__.- 15, [en se | | 
| ee 
*This interval follows the first watering of leaf A too promptly for the growth to be at all 
normal. 
A few measurements at other times agreed entirely with those given 
above in demonstrating that the measurable growth very largely took 
place at night, the diurnal growth of the plants which were seriously 
