398 
Journal of Agricultural Research voi. xxin. No. 6 
Tabus I.— Percentages of iron and manganese found in the different species of seeds — Con. 
GRASSES—continued 
. " . . ' i 
1 
Fc. 
Mn. 
Com (white H K ) . . 
Per cent. 
. OOI7 
. 0026 
. 0078 
Per cent . 
. 0007 
| . OOO4 
.0019 
Com (yellow) .. 
Cane (sorghum). 
Average. 
. OIO7 
i 
. OIII 
miscellaneous 
Sunflower 
Hemp_ 
Flax. 
Rape.. . 
Tobacco.. 
0.0034 
O. OO23 
. 0210 
.0165 
.OO85 
. OO38 
.OO59 
. OO46 
. 0240 
. OO7O 
In the foregoing results the following points of interest are worthy of 
mention. 
In the samples of wheat the average percentage of manganese is slightly 
greater than that of iron, which shows that the capacity of this plant 
for storing manganese in the seed is as great as its capacity for storing 
iron. This fact suggests the possibility that manganese may perform 
a function of equal importance to that of iron in the plant's metabolism. 
In one-half of the number of samples the iron was slightly greater than 
the manganese in the same sample. The largest percentage of manganese 
was found in the Ghirka variety and the largest percentage of iron in the 
Gypsy. 
In a previous article by the writer 7 it was pointed out that manganese 
occurs in greatest concentrations in the outer membranes of this seed 
and least in the starchy, glutinous material in the interior of the endo¬ 
sperm. It is therefore evident that'in the processes of manufacturing 
the highest grades of patent flour most of the manganese is removed in 
the offal. Then, if it should be proved that manganese is also a necessary 
element in the diet, it is apparent that patent flour would contain less 
manganese than whole wheat or graham flour. 
The average results for iron and manganese in oats show that these two 
elements are more nearly equally distributed than in wheat. 
In the preparation of oatmeal for human consumption the manganese 
would not be eliminated in the offal to the extent it is in the manufacture 
of flour from wheat. Therefore oatmeal affords one of the richest sources 
of manganese in food, and it is quite probable that it does add some 
nutritive value to this material. 
The average results for iron and manganese in garden peas and beans 
are approximately the same in each of the different kinds of seeds. It is 
also of interest to note that the iron content is more than six times the 
amount of manganese in these seeds. The iron content in peas and 
beans is almost three times that found in wheat and twice the amount 
* McHARGUE, J. S. THE OCCURRENCE AND SIGNIFICANCE OP MANGANESE IN THE SEED COAT OF VARIOUS 
SEEDS. In Jour. Amer. Chem. Soc., v. 36, p. * 33 *-* 536 ‘ 1914* 
