658 
Journal of Agricultural Research votxxni.No 8 
Tabus I .—Pentosan content of the different parts of the corn plant at various stages 
of growth —Continued 
[Calculated on the basis of ioo plants.] 
Series 
No. 
Age. 
Stage of growth. 
Part of plant. 
Dry 
weight. 
Pentosans. 
Total 
pentosans. 
Gm. 
Per cent. 
Gm. 
Duys. 
[Leaves . 
1 , 374-8 
17.6 
242.2 
Stalks. 
1,213.4 
16.3 
198.7 
Husks . 
75 1 - 2 
I 5*3 
114.9 
6 
87 
Silk forming. 
1 Cobs 
488.6 
9.0 
44 * 1 
Silk. 
126.8 
9-3 
11.8 
Roots. 
338.6 
20.3 
68.9 
Leaves. 
1,958.2 
18.1 
3562 
Stalks. 
2,405.2 
16.5 
398.8 
Husks. 
1,128.2 
25.6 
288.8 
7 
12 3 
Milk. 
A O 
17 . 4 . 
732.6 
] V-ODS. 
Silk . 
9 • W 
126.7 
14.5 
18.4 
[Roots . 
458-0 
19.6 
90.0 
[Leaves. 
i. 493 -o 
19.4 
290.3 
Stalks . 
1 . 950-5 
19*5 
380.7 
Husks . 
1,019.0 
33 -o 
336.4 
Q 
137 
Dent 
Com . 
3 , 554.2 
6.4 
227.4 
O 
Cobs . 
1,212.5 
31,8 
386.1 
Silk . 
93 -o 
19.9 
18.5 
[Roots . 
615.2 
21.8 
134-4 
It is apparent that there is an immediate increase in the absolute 
quantity of pentosans in the plant. Even at the first stage when the 
shoots are only about io inches high the increase in the quantity of 
pentosans in the plant over the quantity in the kernels is 66 per cent. 
This indicates the conversion of starch or other dry matter into pento¬ 
sans. At the second stage, when the shoots are only a few inches tal¬ 
ler, the increase has mounted to 80 per cent. At the third stage the 
increase is several thousand per cent and thereafter increases enormously 
at each stage of growth. It will be noted that at the first stage the 
dry weight as compared with that of the kernels is about 20 per cent 
less, as is to be expected. At the next stage the dry weight has again 
reached that of the com kernels and thereafter increases, except for the 
last stage where the dry weight is slightly less than in the preceding 
stage. It will be noted that throughout the growth of the plant the 
pentosans increase proportionately with the dry matter, the weight ol 
pentosans being approximately one-sixth that of the dry matter. 
Another fact of interest is the variation in the percentage of total 
pentosans in the different portions of the plant at the various stages of 
growth. From 7.4 per cent in the com kernel the percentage has in¬ 
creased to 11.6 in the tops, and 19.5 in the roots of the plants at the 
second stage of growth. From this stage to maturity the roots show 
only a slight increase. The tops have not as yet reached the maximum 
percentage and increase rapidly as the plant develops. As the different 
parts of the plant appear they contain a low percentage of pentosans, 
but there is a rapid increase as these parts develop. This is especially 
true of the cob, which shows an increase from 9 per cent to 32 per cent. 
