Exemption under section 13(b)(4), like exemption under section
13(a)(5),
depends upon the employment in the actual activities named in the
section, and an employee performing a function which is not necessary to
the actual conduct of a named activity, as explained in Sec. 784.106, is
not within the exemption. It is also essential to exemption that the
operations named in section 13(b)(4) be performed on the forms of
aquatic life specified in the section and not on other commodities a
substantial part of which consists of materials or products other than
the named aquatic products. Application of these principles has been
considered generally in the earlier discussion, and further applications
will be noted in the following sections and in the subsequent discussion
of particular operations mentioned in the section 13(b)(4) exemption.
