120 
AMERICAN JOURNAL OF BOTANY 
[Vol. io, 
decrease in size of the lemons there was a corresponding decrease in the 
water content. While there was not an actual decrease in water content 
from February io to March 9, yet the increase was very small, far from com¬ 
mensurate with previous increases. 
Table i. Growth rate, water content, acidity, and color of lemons at different stages of 
maturity 
Date, 1920 
and 1921 
Average 
Diameter 
(cm.) 
Percent, Each Color 
pH Value 
Water Content 
(percent) 
Green 
Silver 
Yellow. 
Stylar 
End 
Stem 
End 
Stylar 
End 
Stem 
End 
Sept. 10. 
2.17 
100 
4.46 
4.46 
53-97 
53.68 
Oct. 9. 
2.86 
100 
2.91 
3.08 
7542 
74-50 
Nov. 10. 
3-34 
100 
2.64 
2.71 
81.45 
81.61 
Dec. 10. 
3-63 
100 
2-54 
2.50 
83.03 
82.16 
Jan. 10. 
3-9i 
68.1 
31-9 
2.60 
2.64 
84.01 
84.21 
Feb. 10. 
4.60 
18.9 
75-8 
57 
2-57 
2-54 
85.57 
85.69 
Mar. 9. 
4-53 
11-4 
64-5 
24.1 
2-33 
2.36 
8574 
85.93 
Apr. 11. 
473 
6.8 
71.6 
21.6 
2.30 
2-33 
86.73 
86.72 
May 9. 
4.92 
4.8 
76.2 
19.0 
2.23 
2.27 
88.99 
88.59 
June 9. 
5.18 
One Lemon 
73-o 
25-1 
2.29 
2.33 
89.99 
88.82 
July 8. 
5.16 
One Lemon 
71.2 
26.4 
2.29 
2-33 
88.20 
87.30 
Average 
2.65 
2.69 
82.10 
8175 
The facts that on the dates of two measurements, March 9 and July 8, 
the lemons were actually smaller than at the time of the preceding meas¬ 
urements, and that these decreases in size were accompanied on March 9 
by only a very slight increase in water content and on July 8 by an actual 
decrease, raise the interesting question as to what may have been the cause 
of these conditions. The results of the following experiments give a direct 
answer to this question. 
1. Lemon branches about 45 cm. long, each bearing from 1 to 3 mature 
or nearly mature lemons, were brought into the laboratory. The lemons 
were detached from half of the branches while the remaining branches were 
left as brought from the grove. The detached lemons, the branches from 
which they had been taken, and the branches bearing lemons were all 
placed on the laboratory table. At the end of 24 hours it was found that 
the detached lemons, as nearly as could be detected by the touch, were 
firm and in normal condition while the leaves on the branches from which 
these lemons had been taken were wilted and drooping. On the other hand, 
the leaves on the branches to which the lemons were still attached retained 
their luster and were normally rigid and upright while the lemons on these 
branches had become quite soft to the touch. 
Further experimentation showed that the leaves on branches from which 
the lemons had been detached showed signs of wilting within a very few 
