As noted in Sec. 780.804, it is ginning of seed cotton which
converts the cotton to marketable form. Section 13(b)(15), however,
provides an exemption only where the cotton is actually ginned ``for
market.'' (Wirtz v. Southern Pickery, Inc. (W.D. Tenn.) 278 F. Supp.
729.) The ginning of cotton for some other purpose is not exempt work.
Cotton is not ginned ``for market'' if it is not to be marketed in the
form in which the ginning operation leaves it. Cotton is not ginned
``for market'' if it is being ginned preliminary to further processing
operations to be performed on the cotton by the same employer before
marketing the commodity in an altered form. (Compare Mitchell v. Park
(D. Minn.), 14 WH Cases 43, 36 Labor Cases 65, 191; Bush v. Wilson &
Co., 157 Kans. 82, 138 P. 2d 457; Gaskin v. Clell Coleman & Sons, 2 WH
Cases 977.)