for the shades of blue and violet draperies. As a chemist, Chevreul first tested the wools dyed in black in his workshop and compared them with those dyed in the best places from London and Vienna. After a careful comparison, he realized that the quality of the dyed material was not in question. This led him to raise a brilliant hypothesis: the lack of strength of the blacks was not due to the dyes or their uptake but was a visual phenomenon related to the colors juxtaposed to the blacks. This new discovery was all the more surprising as Chevreul, being a chemist, was not prepared to admit that the cause of the phenomenon he observed “is certainly at the same time physiological and psychical” ([12], p. 101).

Indeed,the United States is governed by

both international convention and U.S. law.

         A.    The Convention on International Trade in Endangered Species of Wild
               Fauna and Flora

       International trade in African elephants and other protect wildlife is governed by the

Convention on International Trade in Endangered Species of Wild Fauna and Flora (“CITES”).

27 U.S.T. 1087; T.I.A.S. 8249, Mar. 3, 1973. This treaty, which establishes requirements for

importing and exporting covered species, categorizes species into three appendices, depending

on the level of protection each species requires. Relevant here, Appendix I includes species

threatened with extinction, and Appendix II includes species for which trade is