Fig. 280. Section of grain of wheat.
The germ itself is also a very nutritious food for man; hence the seed is eaten, "baby and all." In the corn, those kernels with the largest germs have the largest food value, and, therefore, to-day corn breeders are developing kernels with very large embryos.
If we examine the microscopic structure of the food part of a grain of wheat ([Fig. 280]), we find that there are two outer layers, a and b. Next there is a row of cells d that divides these outer layers from the flour cells within. This is the aleurone layer. At e are the flour cells which constitute the central portion of the wheat kernel. They contain starch, and also gluten, and some oil, and some mineral substances. In grinding to make white flour, the miller tries to leave the aleurone layer of cells d with the outer layers a and b, for if it is mixed with the flour the latter spoils much sooner, and it is also darker in color. In the seed is a ferment that helps digest the food for the young plant.
In order to think more intelligently about our use of food, let us find out, if we can, which parts of the food stored up by the plant for its sustenance are used by us both for ourselves and our livestock. The intelligent farmer gives his stock a carefully balanced ration, i. e., food that is well proportioned for the growth and product of the animal. If he wishes his cows to give more milk he may give them more proteids in their food, and less starch and fat. If he wishes to fatten them he may give them a greater amount of starch and fat and less of the proteids. In order to know what these proteids and starch and fat mean, both to us and to the plant, we have to know a little chemistry. The following table may aid us in this:
| Nutritive substances which contain nitrogen. | { | Proteids (casein, gluten, legumen, etc., albuminoids, gelatine, white of egg, etc.). |
| Nutritive substances which do not contain nitrogen. | { | The carbohydrates (sugar and starch). Fats (oils, butter). |
| Mineral substances. | { | Lime, phosphorus, sulfur, etc./ |
The substances mentioned in the above table are all needful to sustain the life of man and beast. If we compare the body to a steam engine, then we can see that its whole framework is built out of the proteids, mineral matter and water. The starch and sugar and fats constitute the fuel used to heat the boiler and make the engine move. Strictly speaking the proteids are also used somewhat as fuel, as well as for framework. It is easily seen from this that in order to be healthy we should try to give ourselves food containing a proper amount of building material to repair the breakage and wear and tear in the engine, and also give ourselves enough fuel to make the boiler do its greatest possible work. For if we do not have sufficient building material we break down, and if we do not have sufficient fuel we lack energy. Food thus properly proportioned is called a "well balanced ration."
A well balanced ration per day for the average human being is as follows:
| Proteids, | .40 | lbs. |
| Starch, | 1.00 | " |
| Fats | .40 | " |
| Mineral matter, | .10 | " |
| —— | ||
| 1.90 | lbs. |
The above is the amount of nutriment necessary, and in addition to this there should be sufficient bulk to keep the digestive organs healthy. We are just now entering upon the era of intelligence in relation to our food. It seems strange that this intelligence should first be applied to our domestic animals rather than to man. As soon as the farmer discovered that to make his animals pay better he must give them the right proportions of building material and fuel for energy, he demanded that the agricultural chemists give him directions for mixing and preparing their food. But how few of the cooks in our land understand in the slightest degree this necessity for the proper proportions to our food! When they do we may look forward to entering upon an era of serene good health, when we shall have strength to bear and ability to do.
In answering the following list of questions you may be obliged to consult with the miller, or feed-dealer, but it is to be hoped that you will gain a clear conception of the parts of the seed used in making foods from cereals.