Subject to all applicable provisions and limitations of the Class 520 Class Definition, this class provides for solid synthetic resins derived from at least one saturated material and from
A. a reactant which is a cellular material derived from a plant or animal source (other than diatomaceous earth, blood, cotton, or farinaceous flour),
B. a reactant which is a protein or biologically active polypeptide,
C. a reactant which is a carbohydrate or derivation thereof,
D. a lignin, tannin, or derivative thereof,
E. a reactant which is coal or bituminous material, an extract or derivative thereof, or a fatty still residue,
F. a reactant which is a natural resin or derivative thereof (other than tall oil or a derivative thereof).