Abstract
The property producing a field has a qualitative and a quantitative aspect. The former may appear as1, 2, 3,..., n possibilities in the source particles. Interaction lines representing the field must reflect these possibilities. Thus, one expects there to be1, 2, 3,..., n respective kinds of lines joining particles. The different lines interact with each other as well as with the particles at their ends. For gravitational fields,n is1; for electromagnetic fields,n is2; for chromodynamic fieldsn is3. Rest mass can be created by itself out of energy. But a positive-negative pair is the minimum possibility with electric charges, and a color-anticolor pair with quarks. A triplet of quarks or antiquarks, together with the appropriate neutrino, could also arise out of energy