xiii, c, b Brown and Trelease : Shrinkage and Elongation 357 
Table II . — Measurements of shoots of plant 2 of Cestrum noctumum at 
various hours of the day and night. 
Tempe- 
rature. 
Evapo- 
ration 
per 
hour. 
Measurements. 
Time. 
Illumination. 
Shoot 
1. 
Shoot 
2. 
Condition of shoots. ^ 
p. m. 
1.30 
cc. 
1.38 
cm. 
4.05 
cm. 
4.55 
2. 30 
1.20 
4. 05 
4. 60 
Very slightly wilted. 
Straight. 
Curved upward. 
4.00- ... 

0. 84 
4. 10 
4.60 
6. 00 
27 
0. 90 
4.20 
4.70 
a. m. 
7.00 .... 
25 
0. 24 
4.60 
5.00 
Do. 
8. 00 
28 
0. 58 
do 
4.60 
5.05 
Do. 
9. 00 
29 
1. 34 
4.60 
5.00 
Slightly curved 
downward. 
Evidently wilted. 
. 10. 00 
31 
1.63 
do 
4.56 
5.00 
11.00 
29 
1.63 
Diffused light __ 
4. 60 
5.05 
Straight. 
12 noon 
30 
1.44 
Sun _ 
4.60 
5. 00 
Slightly wilted. 
p. m. 
1.00 
33 
2.30 
do . _ 
4.55 
5. 00 
Much wilted. 
2.00 
33 
2.40 
Partial shade- - . . 
4. 60 
4. 95 
Slightly wilted. 
3.00 
32 
2.11 
Shade _ . 
4.60 
5. 00 
Straight. 
4. 00 
32 
2. 21 
do __ _ 
4.60 
5.00 
Do. 
5.00 
30 
2.21 
do 
4. 60 
5.05 
Curved upward. 
6.00 
27 
1.34 
Dusk . . 
4.65 
5. 05 
Do. 
8.00 
27 
0.72 
Dark .___ 
4.70 
6.05 
Do. 
L 
give an accurate measurement of evaporation near the latter. 
The shoots on the second plant were not so vigorous in ap- 
pearance as those on the first and showed slower rates of 
growth; wilting was, moreover, less prolonged. The shoots on 
the second plant were first measured at 1.30 p. m., April 29, 
and measurements were continued until 8 p. m. on the follow- 
ing day. At the time of the first measurement they were exposed 
to direct sun and were very much wilted. An hour later they 
were in partial shade and were only slightly wilted. At 4 
p. m. they were in the shade and were straight, and at 6 p. m. 
they were apparently very turgid and curved upward. This 
whole period, therefore, may be considered as one during which 
the plants were recovering from a wilted condition, and during 
it both shoots elongated 1.5 millimeters. At 7 o’clock in the 
morning the following day they were still curved upward; one 
had increased in length 4 millimeters and the other 3. At 8 
o’clock they were still in the shade and still curved upward. One 
showed no change in length, while the other had increased 0.5 
millimeter. At 9 o’clock they were exposed to the direct sun. 
By 10 o’clock, while still in the sun, they were evidently wilted, 
