370 
AMERICAN JOURNAL OF BOTANY 
[Vol. io, 
Table 3. Continued . 
Tree 
Branch 
Treatment 
Date 
Sampled 
Number of 
Leaves 
Area 
(sq. 
dec.) 
Dry 
Wt. 
(g.) 
Nitrogen 
Total 
(mg.) 
Nitrogen 
per sq. dec. 
In¬ 
crease 
per 
Unit 
Area % 
Nitrogen 
per g. 
mg. 
Rel. 
mg. 
Rel. 
c 
Leaves 
close to 
tip 
7/21 
10 
3477 
2.010 
4 
00 
21.2 
36.7 
Leaves 
close to 
base 
7/21 
10 
5 - 32 B 
3.I4O 
100.38 
18.8 
32.0 
c 2 
Upper 
leaves 
Check (a) 
10/7 
10 
4.199 
3-5679 
128.52 
30.6 
36.O 
c 2 
(b) 
10/7 
10 
3-857 
3.289I 
118.72 
30.8 
36.I 
c 2 
(c) 
IO/7 
IO 
3.670 
3.O776 
112.84 
30.7 
36.5 
c 2 
Id) 
10/7 
10 
4.076 
3.3948 
123.90 
30.4 
36.5 
c 2 
(e) 
10/7 
IO 
4.283 
3-7979 
133-28 
31 .1 
35.1 
Average 
30.7 
100 
36.O 
100 
Upper 
leaves 
c 2 
Ringed (a) 
10/7 
IO 
2.706 
2.I4OO 
30.24 
13.7 
14.I 
c 2 
( b ) 
10/7 
IO 
2.129 
2.OO87 
27.58 
13.0 
13.7 
c 2 
(c) 
10/7 
IO 
1.870 
I.6834 
23.94 
12.8 
14.2 
c 2 
t id) 
10/7 
IO 
4.644 
4-9979 
81.34 
ti 7-5 
f 16.3 
Average 
13.2 
43 
I4.0 
39 
Lower 
leaves 
Co' 
Check (a) 
IO/7 
IO 
5.263 
3-623 
115.92 
22.0 
32.O 
c 2 
(b) 
10/7 
IO 
5.412 
3-9376 
130.76 
24.2 
33-2 
c 2 
(c) 
10/7 
IO 
5.198 
3.6550 
101.08 
19.4 
27.7 
c 2 
(d) 
10/7 
IO 
4-599 
3.1287 
96.04 
20.9 
30.7 
c 2 
(e) 
10/7 
IO 
4-934 
3-7445 
133.00 
27.0 
35-5 
Average 
22.7 
100 
31.8 
100 
c 2 
Ringed (a) 
IO/7 
IO 
4.702 
4.1740 
75.64 
16.1 
18.1 
c 2 
(b) 
10/7 
IO 
4.212 
3.5381 
62.44 
14.8 
1 7-7 
Co 
(c) 
10/7 
IO 
4.270 
3-7556 
64.12 
15-0 
17.1 
c 2 
(d) 
10/7 
IO 
4-425 
3-9574 
70.56 
15-9 
17.8 
c 2 
(e) 
10/7 
IO 
3.960 
34688 
61.04 
15-4 
18.1 
Average 
15.5 
68 
17.8 
56 
t These leaves were rolled like the others but were larger and more basal; not included 
in average. 
above the ring was practically the same as that in the check. This ability 
of a narrow strip of phloem to allow for the transfer of an approximately 
normal quantity of nutrients is comparable to its ability to allow sufficient 
foods and nutrients to pass to insure approximately normal growth, as 
was previously found (Curtis, 1920). 
A somewhat similar experiment was performed with a lilac bush (Syringa 
vulgaris L.). In this case paired twigs were selected, and one of each pair 
was ringed just above the fork. The rings were made on the current year’s 
growth. It was hoped that it would be possible to analyze each twig 
