568 
Journal of Agricultural Research 
Vol. XXI. No. 8 
Table) XVIII .—Summary of results of experiments I to IX —Continued 
Ratio of 
roots to tops 
relative to 
that of con¬ 
trols taken 
as ioo.« 
Assimilation relative to that of controls 
taken as 100.<1 
Mean assimi¬ 
lation of ni¬ 
trogen (N), 
Experiment No. 
Nitrogen 
(N). 
Phosphoric 
acid (P 2 0 ;,). 
Potash 
{K2O). 
phosphoric 
acid (P- 8 > 4 , 
and potash 
(K-jO), rela¬ 
tive to that 
of controls 
taken as 
100 . a 
I. 
J 12 
j 0^ 
79 
01 
74 
82 
06 
88 
I. 
106 
03 
I. 
106 
88 
84 
62 
J 7 
68 
90 
66 
46 
43 
65 
26 
37 
66 
35 
59 
70 
II. 
III . . ... .. 
124 
192 
I -,0 
69 
A s 
Ill. 
67 
hi. ...'........... 
12 I 
9 0 
49 
65, 
45 
8 1 
76 
28 
-IV.. . ... .... ....... 
180 
IV . 
144 
170 
101 
42 
57 
7 7 
iv......;.. 
20 
40 
IX, ; . .JV . . , . : . . . .... : . . . 
76 
68 
76 
.• y,.:.-v. 
0 
81 
. 53 
1 7 
3 ° 
4 t 
64 
46 
2 7 
63 
•'IX. . 
i(k) 
' ' '153 
• 1 11 
42 
•? I 
VI. 
85 
05 
VI. . <.. 
/ 
■ ■■»« 
2 7 
0 1 
5 2 
2 3 
33 
-7 3 
ix';:;.. 
1 73 
j 87 
VII. 
A Z 
0 'i 
3° 
06 
VI 1 . 
1 7 7 
VIII.. 
227 
24 
v) 
14 
4 * 
J c 
1 j 
°Tlie control plant:; were those grown with all their roots in the complete solution. 
The more important facts established in the preceding experiments 
are as follows: • < 
1. Depressions in growth and-in assimilation of nutrients were roughly 
proportional to the incompleteness of the solutions afforded the roots, 
or, in other words, proportional to the extent the nutrients were restricted 
to separate portions of the roots. 
2. Assimilation did not diminish with increasing subdivision of the 
roots among different solutions, unless the division entailed increased 
localization of the supply of the various nutrients. 
3. The more growth and assimilation were depressed by division of 
the roots among incomplete solutions the higher was the ratio of root 
growth to top growth. However, the relation between diminution in 
assimilation and increase in the root to top ratio was not quantitatively 
proportional. 
4. When different portions of the roots were supplied with different 
nutrient solutions, the roots in the more complete solutions generally 
made the greater growth and had a more bushy habit of growth. In the 
solutions lacking two elements the main roots were longer than in the 
more complete solutions, the lateral roots were fewer, and the laterals 
were farther apart on the main root. 
