948 
Journal of A gricultural Research 
Vol. XXIV, Na II 
TabIvE IX. Influence of water in moving nitrogenous and nonnitrogenous material from 
the stems into the wheat kernel 
Average 
Average 
Average weight 
weight 
percentage 
of nitrogen 
per kernel. 
of nitrogen. 
per kernel. 
Out of water: 
Gm. 
Gm. 
Whole heads. 
- 
Half heads. 
W* \J\J / X 
.0077 
2. 02 
2.38 
0. 000 loO 
. 000183 
In water: 
Whole heads. 
nj 0 
3 - 24 
3 - 23 
. 000389 
. 000487 
Half heads. 
• yj X 
.015 
The average weight of the kernels at the beginning of the experiment 
was between 0.0071 and 0.0077 and the nitrogen content varied from 
2.38 to 2.62 per cent. At the close of the experiment, whereas the per¬ 
centages of nitrogen were higher in the whole heads than in the kernels 
of the half heads, the total weight of nitrogen in both instances was 
practically the same. The weights of the kernels and percentage of 
nitrogen in the kernels of the plants which were placed in water had 
increased. The increase in the weight of kernels and the weight of 
nitrogen in the one-half of the kernels left on the head was found to be 
proportionally greater than was obtained for the average of all the 
kernels left intact or, as it is termed in Table IX, the whole heads. In 
other words, the increased amount of material in kernels left on one- 
, half the head if distributed to double the number of kernels would have 
given results similar to those found in all the kernels left intact on the 
head. Translocation of plant food material has been brought about, and, 
because of its more highly nitrogeneous character, it is believed that larger 
quantitip of v/ater are required to move the nitrogenous matter than 
are required to move the nonnitrogenous matter into the kernels. Accord- 
ingly, water should prove beneficial to high rather than low nitrogen 
conteiit. The protein of wheat depends first upon the supply of avail¬ 
able nitrogen {4, v. 10; 5) for the plant, and second upon movement of 
the nitrogenous material into the grain. 
RELATION OF PERCENTAGE OF MOISTURE IN THE KERNELS TO FILLING 
In addition to investigational work mentioned above, the weight of the 
grain, moisture, starch content, etc., were determined at the various 
stages of the development of the kernels. The samples were collected 
every other day, and observations for maximum and minimum tempera¬ 
ture and relative humidity were recorded. The results for weight and 
moisture content of the kernels have been plotted in'figure i. 
Apparently no filling occurs in grain having a moisture content of 40 
per cent or less. The vertical parts of the curves represent measure¬ 
ments made during periods of desiccation. 
The figures for maximum and minimum temperatures and relative 
humidity have not been submitted because it was impossible to show 
conclusive relationship between these figures and those for changes of 
weight of kernels during the period of development. There were 
periods in the development, however, where the cooler nights were 
favorable for greater increases in weight than was found to be the case 
where the warmer nights prevailed. Considering the changes in weight 
